Climate Control

Attempts to regulate the air conditioning (AC) and commercial refrigeration markets for the benefit of the environment are nothing new. During the past 25+ years, various legislative actions have limited the use of various refrigerants that depleted ozone or emitted greenhouse gases, both of which have been shown to contribute to global warming potential (GWP). 

The most recent actions, including the EPA’s Significant New Alternatives Policy (SNAP) program and the much more recent American Innovation and Manufacturing Act (AIM), are further driving growth of low-GWP refrigerants. While this is good news for the environment, these low-GWP refrigerants are not without their own challenges. They may increase energy consumption, introduce added safety risks and require significant equipment modifications. 

 

A history of efforts to benefit the environment 

Refrigeration systems contribute to the emission of greenhouse gases when a leak occurs of a high-GWP refrigerant. The two refrigerants most commonly used in the early days of refrigeration were ammonia and carbon dioxide (CO2). Both proved to be problematic for different reasons. Ammonia is toxic and carbon dioxide requires extremely high pressures to operate in a refrigeration cycle. 

As a result, both refrigerants lost popularity when Freon 12 (dichloro-diflouro-methane) hit the market. Among other benefits, Freon is extremely stable, non-toxic, and operates at moderate pressures. Unfortunately, it was also shown to have a high ozone depletion potential (ODP), which is the primary reason is has since been banned from use globally. 

Numerous other refrigerants have also been banned through SNAP, which was established under the Clean Air Act to identify and evaluate substitutes for ozone-depleting substances. The EPA has since published numerous rules about what is and is not acceptable under SNAP, creating tremendous confusion in the industry. The policies established under SNAP took on greater meaning due to the AIM Act, which went into effect in 2020. The AIM Act requires the EPA to implement a phase down of the production and consumption of hydrofluorocarbons (HFC refrigerants) to reach approximately 15% of their 2011-2013 average annual levels by 2036. HFCs are of particular concern since they are classified as potent greenhouse gases that contribute to climate change. 

 

Pros and cons of preferred low-GWP alternatives carbon dioxide (CO2) and propane (R290) 

Tighter environmental legislation is opening the door for increased demand for low-GWP refrigerants.  

Two of the more popular options on the market today are CO2 and propane (R290). Both have a long history in refrigeration but have recently again emerged as front-runners due to their low environmental impact. CO2 is the more commonly used for many reasons, including: 

• Environmentally safe with a GWP rating of 1 
• Non-toxic and non-explosive, which means it is safe for use in public locations, such as supermarkets 
• Less expensive than synthetic refrigerants 
• Non-corrosive to most component materials and compatible with most compressor lubricants 
• High density, which allows for a smaller pipe size 
• Less noticeable pipeline pressure drops 
• High heat transfer efficiency so heat exchangers can be smaller 
• SNAP-approved for use in many different types of systems 

A key challenge of using CO2, however, is that it operates at a far higher pressure than other natural and synthetic refrigerants. This increases the risk of leaks which, in turn, necessitates the use of more durable, costly components and piping to handle the greater pressure and added controls and other safety features, many of which increase energy consumption due to high ambient temperatures. 

As a hydrocarbon, R290 provides several equally attractive benefits, including superior thermodynamic properties and greater heat capacity. These combined characteristics allow R290 to absorb more heat at an accelerated rate, resulting in higher device energy efficiency with faster temperature recovery and lower energy consumption.  

More importantly from an environmental standpoint, R290 (like all hydrocarbons) has no ozone depleting properties and a low GWP of 3. It is also compatible with materials commonly used in the construction of refrigeration and air conditioning equipment, is readily available and relatively inexpensive. It can be stored and transported in steel cylinders similar to how other common refrigerants are handled.

A major concern about R290 is that it’s highly flammable. That’s why refrigerant charge limits are in place, as well as other special safety standards when using R290. 

 

Overcoming the challenges of CO2 

The higher operating pressure of CO2 creates a few design challenges. But most of these can be overcome, albeit at a higher cost. Key are material upgrades, such as thicker-walled piping or high-strength K65 copper alloys. 

Parker manufactures an array of valves, seals and controllers that are specially rated for CO2 high-pressure refrigeration systems. This includes pressure-rated electric expansion valves, ball valves with integrated pressure relief, stepper motor-driven pressure regulating valves, pulse width modulation valves that manage refrigerant flow and pressure-regulating gas cooler/flash gas bypass valves.

Steel piping is also being used in some instances for high pressure CO2 and the addition of electronic controls which can monitor and record pressures, temperatures and additional parameters. This includes pressure-rated electric expansion valves, ball valves with integrated pressure relief, stepper motor-driven pressure regulating valves, pulse width modulation valves that manage refrigerant flow and pressure-regulating gas cooler/flash gas bypass valves. The use of remote monitoring systems is growing. Not only is remote monitoring a safer option, but it is also in response to the current shortage of trained HVAC technicians, allowing companies to monitor multiple systems and locations with fewer workers. 

 

Overcoming the challenges of R290 

With the high flammability of R290, refrigerator manufacturers need to make the necessary system design changes to align with applicable UL and ASHRAE standards that include charge limits, marking requirements and ventilation requirements. System charges of up to 150 grams are currently allowed for most R290 applications, though a few are even lower. Proposed and under-revision UL safety standards seek to raise this limit as high as 500 grams for open refrigeration appliances, and 300 grams for closed appliances. While some systems or applications would remain with more restrictive charges, these increases promise to open R290 to many more applications and enable new applications. 

To address flammability concerns, Parker manufactures innovative filter driers and thermostatic expansion valves (TEVs) that are designed to minimize the amount of refrigeration system charge when using flammable refrigerants.that are designed to minimize the amount of refrigeration system charge when using flammable refrigerants. 

In addition, some system manufacturers use a sealed design that seals off the spark inside by isolating the R290 from the electrical switch assembly. This type of design reduces the potential for explosion by stopping the gas from entering the electrical switch compartment. 

Another option is to fit the leak detection and control systems such that, when activated, it will pump down the propane charge into a liquid receiver and then shut off the electrical supply. If the compressor is enclosed, a ventilation fan must be installed and activated by the leak detection system to remove any gas that might leak from the compressor into the enclosure. 

 

Preparing for an uncertain future 

Despite the ongoing changes and obstacles presented by various environmental regulations in the U.S. and abroad, the good news is that the necessary product and material innovations are already available to help engineers overcome the design challenges presented by low-GWP refrigerants, such as CO2 and R290.  

 

This article was contributed by Parker Sporlan Division.  

 

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This Climate Control blog is to review the basic refrigeration cycle and the interaction between the four basic components. The four basic components are the compressor, condenser, expansion device, and evaporator. Let's look at each component and its function and then look at what happens when we do not properly match these components.

 

Compressor:

The compressor is the transition point from the system's low-pressure side to its high-pressure side. Its purpose is to compress the cool low-pressure gas/vapor at the evaporator pressure up to the condenser pressure. In the compression process, the heat from compression and possibly motor heat increases the gas's temperature. The vapor entering the compressor is also superheated, which further increases during the compression process. At the discharge of the compressor, the refrigerant is a high-temperature, high-pressure superheated gas. Figure 1 below shows the ideal refrigeration cycle graphically on a Pressure-Enthalpy Diagram. The vertical axis is pressure, and the horizontal axis is enthalpy, or the heat content of the refrigerant per pound of refrigerant circulated. The compressor is the sloped line on the right side. The upper horizontal line is the condenser, the lower horizontal line is the evaporator, and the vertical line on the left is the expansion valve. Please note this is an ideal refrigeration diagram. There is no superheat exiting the evaporator or subcooling exiting the condenser. For a more detailed explanation of the P-H diagram, please refer to Sporlan Form 5-200 in our website's literature section under HVACR Educational Material.

Figure 1.

Condenser:

We task the condenser with removing the heat absorbed in the evaporator, the heat of compression, and heat added by the compressor motor (as long as we use a hermetic or semi-hermetic compressor). This heat removal comes in two forms. First, the gas is desuperheated since the gas exiting the compressor increases in temperature above the saturated condensing temperature. Desuperheating is a sensible temperature change that can be measured as a decrease in temperature as the heat is removed from the gas. After the gas is desuperheated, it is in saturated conditions. At this point, additional heat removal condenses the gas into a liquid and is where the condenser gets its name. This heat removal occurs at a constant temperature and pressure until all the gas is condensed into a liquid, referred to as latent heat change. Keep in mind that the pressure is still at the same pressure when it exited the compressor, minus any small pressure loss from flow losses. Also, anytime there is liquid and vapor present, you are in saturated conditions, such as in the condenser or evaporator. You can use a Pressure-Temperature chart to determine the corresponding temperature from the measured pressure. Be aware of the difference and when to use dew point or bubble point when using a blended refrigerant. After the gas completely condenses into a liquid, any additional heat removal results in a temperature drop or sensible heat change. When the temperature drops below the condensing temperature or the saturated condensing temperature, the liquid is subcooled. Subcooling means we cool the refrigerant below the saturated temperature or, in this case, the condensing temperature. Subcooling is beneficial to prevent the refrigerant from flashing or reaching saturated conditions before the expansion device. Flashing can occur due to pressure drop from pressure losses in the tubing and accessories ahead of the expansion device. Any gas bubbles (flashing) can severely affect the TEV flowrate by reducing the refrigerant volume that can pass through the expansion device orifice.
 

Expansion device:

The expansion device is the transition point from the system's high side to its low side. The expansion device drops the pressure from the high side pressure, referred to as the discharge pressure or condenser pressure, to the low side pressure. You may also refer to the low side pressure as the suction pressure or evaporator pressure. For this example, we use the Thermostatic Expansion Valve (TEV) as the expansion device. Other expansion devices could be a capillary tube, fixed restrictor, automatic expansion valve, or an electric expansion valve. These devices all have their benefits when weighing cost and performance or efficiency. The thermostatic expansion valve or TEV controls the superheat exiting the evaporator. In doing so, it controls the proper amount of refrigerant flows into the evaporator under all load conditions. As the load increases, the superheat increases driving the TEV further open to match the amount of refrigerant boiled off in the evaporator. Vice versa, if the load decreases, the superheat decreases driving the TEV in a more closed position.
 

Evaporator:

The evaporator is the component that the other components are supporting. The evaporator removes the heat from the space you want to cool, whether it is a walk-in cooler or freezer, supermarket case, or an A/C unit. When the refrigerant leaves the TEV, it is a refrigerant liquid and vapor mixture. The vapor exiting the TEV is due to the refrigerant boiling at the lower pressure and cooling the liquid down to the desired evaporator temperature. When the refrigerant mixture enters the evaporator, it continues to boil at constant pressure and temperature. As it changes from a liquid to a vapor, it absorbs the heat flowing across the evaporator at the desired temperature. Evaporators may also be used as heat sinks to cool computer chips, machinery, or other items.

 

Matching or mismatching of components:

The secret to an optimally performing refrigeration or air conditioning system is matching all the components to balance the system. If one or more of the components are oversized or undersized, poor performance could result and higher energy costs.

For example, let us start with a 3 ton or 36 MBH(36,000 BTU/hr) system with all the components properly matched for the load. When we match the components correctly, we maintain the desired evaporator temperature at design conditions. Let us analyze what would happen if we replaced the 36 MBH compressor with a 48 MBH compressor, with everything else remaining the same. The first issue is the higher cost for a larger compressor, but we selected a larger compressor in this case. Since the compressor is now larger, the evaporator's pressure with a larger displacement compressor operates at lower suction pressure and lower evaporator temperature. Lower suction pressure results in a compressor that can cause short cycling, higher energy cost, and a shortened compressor life. Lower suction also causes a higher TD (temperature difference) across the evaporator coil, increasing its BTU capacity. It can also result in a different relative humidity than desired and possible coil frosting or icing since the TD is now higher across the coil. The increase in TD also causes an increase in the evaporator capacity and results in a higher flow rate than design through the expansion valve. If not sized for the new compressor, the TEV is not large enough for the system and starves or operates at a higher superheat. The compressor EER or Energy Efficiency Ratio also decreases due to the lower operating suction pressure meaning less BTU removed per Watts of energy consumed.

The result of installing a smaller compressor would be the obvious lower system capacity and not meeting the required design conditions or comfort for space. Also, the TEV would be oversized and could hunt. Also, the evaporator would operate at a higher pressure/temperature resulting in possible poor humidity control.

Moving around the system, if everything else is equal, what happens if the condenser is oversized? The drawbacks to an oversized condenser would be increased system refrigerant charge and increased equipment cost, and possibly operating issues during cold ambient conditions. However, there are benefits to an oversized condenser when properly evaluated by equipment manufacturers. Everyone has noticed that condensers are much larger than in past years on residential air conditioning units. The condensers in these systems have increased in size to meet the new SEER ratings, and a larger condenser helps increase the SEER rating of the system and reduce energy consumption.

An undersized condenser results in higher discharge temperatures, added stress on the compressor, and higher energy cost. It could also cause oil and refrigerant breakdown and result in a premature compressor failure.

It is always wise to properly size the TEV to match the compressor and evaporator capacity. Undersized TEVs starve the evaporator resulting in low suction pressure and poor system performance and temperature control. A starving valve (high superheat) can also cause high discharge temperatures and compressor overheating. An oversized TEV can result in TEV hunting because it overshoots its superheat setpoint due to the oversized valve port. Additionally, a hunting oversized valve could cause flood back to the compressor and damage to the compressor. A hunting valve also causes poor system performance as the valve overfeeds and underfeeds.

Evaporators need to be correctly sized to extract the correct amount of heat to meet the design load. If undersized, they operate at a lower suction pressure affecting/reducing the space's humidity and causing the compressor to operate at a lower pressure than design, resulting in higher energy costs. If oversized, it could result in better energy efficiency, but it could adversely affect the humidity, which could be undesirable if used for comfort cooling. Sizing the evaporator becomes a balancing act like the other components between comfort or desired result and energy efficiency.

 

Conclusion:

These are just some examples to look for when installing or replacing equipment components. As well as these examples, there are other considerations when diagnosing a system; a change in entering air temperature, relative humidity, outdoor air temperature, dirty filters or condensers, and many other factors. When troubleshooting, look at the basics and check temperatures and pressures. If these numbers are not correct, check and verify what could be influencing the pressures and temperatures.

 

HVACR Tech Tip Article contributed by Pat Bundy, application engineer, Sporlan Division of Parker Hannifin

 

 

 

 

Additional HVACR Tech Tips helpful for you: 

HVACR Tech Tip: 12 Solutions for Fixing Common TEV Problems

HVACR Tech Tip: Understanding and Preventing Superheat Hunting in TEVs

HVACR Tech Tip: Considering a Refrigeration System Retrofit? Part 1

Annual Walk-in Energy Factor (AWEF) is an energy standard by the Department of Energy (DOE) that measures electrical energy input versus its cooling capacity. All commercial refrigeration equipment manufacturers should comply with the AWEF rating specified by the DOE. HVAC equipment of 3000 ft² or less must conform to this new requirement. All new walk-in installations should be with an AWEF compliant unit. Furthermore, anytime a replacement unit is installed, it needs to comply with AWEF.

There are several ways original equipment manufacturers (OEMs) can achieve the AWEF rating. These include adding an electric expansion valve, oversizing the condenser, on-demand defrost, among others. However, the most economical way to achieve AWEF is to lower or float the system head pressure.

Traditional head pressure settings are anywhere from 180 psig to 295 psig, depending on the system refrigerant. This setting maintains the system's high side temperature and pressure like a summer condition year-round. OEMs are now using head pressures as low as 123 psig for medium-temperature applications and 100 psig for low-temperature applications. This lower head pressure setting significantly impacts expansion valve sizing. In the winter, the cold temperatures allow for more compressor capacity. However, less capacity is available from the expansion valve counteracting the compressor capacity.

An expansion valve's capacity is determined by the liquid temperature and pressure drop available. The colder the liquid temperature, the more available capacity the valve has; the greater the pressure drop, the greater the available capacity. In winter, the expansion valve has a colder liquid temperature, but there is very little pressure drop available to the valve due to reduced head pressure resulting in a much lower available capacity. The result is a larger than expected expansion valve needed in AWEF applications.

In the below example, look at what happens in the system before lowering head pressure. Using R-407A, 100°F condensing temperature (238 psig), 5°F subcooling, and -10°F (15 psig) saturated suction temperature, there is 192 psi available to the valve in this scenario, assuming an appropriately sized distributor with about 31 psi drop across it.

If the head pressure gets floated down to 100 psig, there is much less available capacity. At the colder temperature, the compressor now has approximately 2.7 tons. The cold liquid temperature makes the distributer oversized, so we only get 14 psi across it, resulting in an available pressure drop of 71 psi across the expansion valve.

To counteract this problem and make sizing valves easier for our customers, Parker Sporlan has researched compressor efficiencies, distributor sizing, and valve sizing at the maximum summer condition and the minimum winter condition for AWEF applications. Bulletin 500-10-AWEF provides expansion valve capacity information for AWEF applications. The bulletin helps the contractor and wholesale counter employee to be able to accurately size and select the proper expansion valve for AWEF applications. The values presented in 500-10-AWEF provide maximum and minimum BTU/hr load at the unit's rated condition. Most times, this rating is at 105°F condensing temperature and 96°F liquid temperature. Recommendations in Bulletin 500-10-AWEF are per AHRI 1250. This bulletin helps provide thermostatic expansion valve selections for AWEF applications. Download Parker Sporlan Bulletin 500-10-AWEF.

View how to properly size an expansion valve for a DOE AWEF compliant system in this short video.

 

HVACR Tech Tip Article contributed by Jason Forshee, application engineer, Sporlan Division of Parker Hannifin

 

 

 

 

 

Additional HVACR Tech Tips helpful for you: 

HVACR Tech Tip: Basic Troubleshooting Given Three Measurements

HVACR Tech Tip: Principles of Thermostatic Expansion Valves

HVACR Tech Tip: Where Should the TEV External Equalizer Be Installed?

As we introduced our Parker Sporlan webinar series we realized that we couldn't possibly answer all the questions in that short amount of time. We decided to create Climate Control blogs to answer some of the more pressing questions. This is the third of three blogs answering questions from our Supermarket Seminar Series: Metering Devices, TEVs.
 

TEV - Selection:

Q: What is the minimum pressure difference across the TEV?

A: The existence of pressure-drop helps to facilitate flow through the thermostatic expansion valve or TEV. At some point, flow won’t occur if the pressure drop is too low. Manufacturers will typically provide ratings for expansion valves with a minimum pressure drop of 30 psid across the TEV. This does not include the pressure drop that would occur across the distributor if present in the system and the pressure drop across the evaporator.

Q: The pressure drop across TEV in the Correction Factor table ranges widely, 30 to 275 psig. How does a TXV with a widely varying condensing pressure act, say a freezer that condenses from 150 psig winter to 250 psig summer?

A: The ratings in the capacity tables for Sporlan TEVs are in accordance with ANSI/ARI Standard Number 750. The proper valve selection is critical to offering a good balance of control over the varying conditions. The TEV will ultimately attempt to control superheat at the bulb location even under varying conditions. As conditions vary, a situation may occur that is beyond the ability of the TEV to control superheat at the bulb location. Adjustment or replacement of the TEV may be required. In more extreme cases, there may exist a need for the hot gas bypass to control low side pressures and a head pressure control system to control high side pressures in order to stabilize system conditions. You stack the odds in favor of the TEV being able to control superheat with stable conditions. We recommend using our Virtual Engineer program to properly select valves based on those varying conditions.

Q: We need a TEV rated for R449A, but we don't have it in stock. Could we use a similar TEV rated for R22 as a replacement?

A: The mass flow rate for R449A is 7 to 10% higher compared to R22 depending upon system conditions. The Net Refrigerating Effect (NRE) of R22 is slightly higher compared to R449A as expected. In general, the existing R22 TEV will serve as a suitable replacement for the R449A application; however, this is no guarantee. It is good practice to evaluate the existing components with appropriate selection software or ratings tables using the new system conditions.
 

TEV - System & Valve Analysis:

Q: In the age of energy savings and reduced head pressure during cool weather conditions, what should we watch out for? How would we detect a problem with the TXV?

A: The TEV is intended to control superheat at the sensing bulb location. Determining the superheat at the bulb location is one way to determine if something is amiss. Careful product selection and system commissioning is ever important today. System monitoring during various conditions is key with these new reductions in head pressure (walk-in coolers, etc.). There are many system parameters that should trigger an alarm condition and ultimately indicate some control problem has occurred. Low or High superheat at the bulb location would be one such condition. Unfortunately, a problem may not be detected until the case is warm and the product has been lost. Utilization of Sporlan’s Virtual Engineer program can assist with proper valve selection and help get things started correctly.

Q: On the MOP charge migration concern, wouldn’t heating the element affect valve function?

A: Yes, it will but in a good way. If the thermostatic charge constituents have all migrated to the diaphragm housing, the TEV will not be operational and it will not be controlling superheat at the bulb location. By warming the diaphragm housing or element, the charge constituents will be forced back into the bulb, once again making the TEV operational. A warm rag on the diaphragm housing can be used to determine if charge migration has occurred. The diaphragm housing should always be warmer than the bulb, especially with MOP-style thermostatic charges.

Q: If hot gas for capacity control is being utilized and introduced before the evaporator, how does that affect the bulb and valve?

A: In this instance, the hot gas will be mixed in the evaporator with the refrigerant being introduced from the TEV. The TEV will simply do its job of controlling superheat at the bulb. It will be influenced by the load on the evaporator and the hot gas that has been introduced at the inlet of the evaporator. In this scenario, the TEV will continue to act as the same superheat control that it did prior to the introduction of the hot gas. However, it will also act as a desuperheating device to temper the discharge gas.

Q: Why don’t manufacturers use bleed ports more often since it helps start the compressor?

A: Good question, maybe we should ask the equipment manufacturers. Bleed Ports are handy for restarting a unit against a pressure differential, for fine-tuning TEV capacity, for maintaining minimum suction pressure during startups when the system is equipped with a micro-channel condenser and the list continues. However, bleed ports prevent TEVs from seating tightly and this can complicate the ratings process for manufacturers.

Q: Why do compressor manufacturers generally expect a higher superheat at the compressor inlet as compared to the evaporator outlet?

A: The TEV is intended to control superheat at the sensing bulb location. As the superheated refrigerant travels through the suction line on the way to the compressor inlet, ambient conditions can contribute to the superheat of the refrigerant. This can happen if the suction line is uninsulated or if it is routed through high-temperature areas on the job site. This becomes a balancing act. Too little superheat at the compressor inlet and a flooded condition may damage the compressor. Too much superheat and the compressor may overheat.

For more information on TEVs see Parker Sporlan Bulletin 10-10-8, Bulletin 10-9, Bulletin 10-10.

For more information on Parker Sporlan products please visit our website.

 

Article contributed by Jim Jansen, senior application engineer, Sporlan Division of Parker Hannifin

 

 

 

 

 

Additional resources on HVACR Tech Tips:

Parker Sporlan Supermarket Seminar Series: Metering Devices, TEVs - Q&A Part 1

Parker Sporlan Supermarket Seminar Series: Metering Devices, TEVs - Q&A Part 2

HVACR Tech Tip: Understanding and Preventing Superheat Hunting in TEVs

HVACR Tech Tip: Everything You Want to Know About Superheat

ZoomLock MAX press-to-connect flame-free refrigerant fittings help to improve productivity for HVACR contractors and technicians on the job. Having the ZoomLock MAX complete system equipped with all the sizes and configurations you will need simply saves time and improves safety and efficiency.

This post is the last blog in our series providing answers to the top FAQs on ZoomLock MAX. The Q & As cover refrigerants and oils, and installation technicalities for fittings, leaks, sealing, temperature, and system compatibility. 

 

Applications

ZoomLock MAX fittings are designed for the following applications:

• Refrigeration

• Air Conditioning

• Heat Pump (Refrigeration Side)

 

Download the full list of FAQs in this handy guide and learn more about ZoomLock MAX.

 

  Q: What approved refrigerants are for use with ZoomLock MAX?

A: ZoomLock MAX is approved for use with R-32, R-134a, R-404A, R-407C, R-407F, R-410A, R-507, R1234ze, R1234yf, R-718, R-450A, R-513A, R-448A, R-449A, R-407A, R-427A, R-438A, R-417A and R-422D. 
 

Q: What approved oils are for use with ZoomLock MAX?

A: Use ZoomLock MAX for approved POE, PAO, PVE, AB, and mineral oils. The O-ring has been tested successfully with PAG oil; however, you should not use PAG oil with copper systems due to the potential for corrosion of the copper material.
 

Q: If ZoomLock MAX leaks on installation, can you braze the fitting rather than cutting out the joint and having to replace the missing tube?

A: No, if a pressed fitting is leaking, the fitting must be cut out and replaced. You should not attempt to braze the fitting as you may melt the O-ring material and thus introduce contaminants into the system that could cause other system issues.
 

Q: Is there a concern about ice building up and then thawing under the fitting in a horizontal or vertical configuration?

A: No, ZoomLock MAX has been thoroughly freeze/thaw tested.
 

Q: Are there any concerns with corrosion where installations are made in coastal areas or with cleaning agents?

A: No, ZoomLock MAX has been Acid Salt Spray tested to ASTM G85. As with all copper installations, avoid exposure to ammonia.
 

Q: Does the O-ring compensate for imperfections in the tube to make a tight seal?

A: Yes, the O-ring does compensate for small/minor scratches on the surface of the tube. However, avoid imperfections adjacent to the crimp area such as scratches, incise marks, and tubing that is not round. Reference copper piping standard for roundness.
 

Q: Product specifications state that the application temperature limits are -40 F to 300 F, what happens if we go beyond that limit?

A: If you use ZoomLock MAX in an application that the fitting goes beyond the specified limits of the O-ring, then there is an increased likelihood that a leak can occur due to the compromised O-ring.
 

Q: How clean are ZoomLock MAX fittings?

A: ZoomLock MAX fittings comply with the cleanliness standards as required in the Copper Tube Standards EN 12735-1 and ASTM-B280. Keep the zip closure bag sealed to protect fittings from contamination.
 

Q: How do the fittings cope with vibration from the system?

A: Vibration is a recognized cause of leaks, design the system, and install to comply with all local standards and codes of practice, which aim to minimize vibration. Extensively tested ZoomLock MAX fittings ensure the joint doesn’t leak as a result of system vibration and complies with the following standards:

• ISO 14903, Temperature Pressure Cycling and Vibration Test

• UL 109 - 8, Vibration Test

• UL 207, Fatigue Shock Test
   

Q: Will the O-ring be damaged if acid develops in the refrigeration system?

A: Good installation practice, a nitrogen purge during any brazing (not required with ZoomLock MAX mechanical fittings), a deep evacuation, and the proper installation and use of filter-driers containing new and effective molecular sieve desiccants prevent many system failures including the buildup of acid within the system. When selecting which desiccant material is best for an application, consider water capacity, refrigerant and lubricant compatibility, acid capacity, and physical strength, which are essential characteristics of desiccants.
 

Q: When pressed, small size fittings, mainly elbows, may allow a small amount of rotational movement at the joint. Will this affect the security of the joint?

A: No, some rotational movement is quite acceptable, the joint will not leak, nor will it come apart under the pressure loading and during system operation. Some joint movement is good and allows for expansion and contraction in the system pipework.
 

Q: Is ZoomLock MAX suitable for medical gas applications?

A: No, ZoomLock MAX is not suitable for medical gas applications.
 

Q: Can you press a fitting more than once?

A: No, only press ZoomLock MAX fittings once.
 

Q: Is ZoomLock MAX approved for drinking water systems?

A: No, do not use ZoomLock MAX for drinking water systems.
 

Q: Can ZoomLock MAX be used on heating and hot water systems?

A: No, use ZoomLock MAX for air conditioning and refrigeration applications only.
 

Q: I need to pull a vacuum, how deep of a vacuum can I pull?

A: Pull 200 microns for a deep vacuum.

 

Improved productivity equates to more profitability for your business

ZoomLock MAX technology is the next generation of the press–to–connect copper refrigeration and air conditioning fittings—and flameless connections. Now, HVACR professionals can safely make secure leak-free connections in seconds without the use of a brazing torch or press tool. Adding all that time savings allow for more scheduled jobs and greater profitability potential for your business.

Ready to learn more? Visit the ZoomLock MAX website to download the full FAQs sheet, schedule a demo, watch it in action, get training support, locate a distributor, and get started today!

 

 

 

 

 

 

 

Article contributed by Chris Reeves, product manager, Contaminant Control Products, Sporlan Division of Parker Hannifin. For more information on Parker Sporlan products please visit our website.

 

 

 

 

Related, helpful content for you:

ZoomLock MAX Press-to-Connect Refrigerant Fittings FAQs–Part 1

ZoomLock MAX Press-to-Connect Refrigerant Fittings FAQs– Part 2

HVACR Tech Tip: What Every Technician Needs to Know About Refrigeration Oils

HVACR Tech Tip: Guide to Servicing Blended Refrigerants

Parker Sporlan Supermarket Seminar Series: Metering Devices, TEVs - Q&A Part 1

 

ZoomLock MAX press-to-connect refrigerant fittings are changing the way HVACR professionals connect refrigerant lines. By using ZoomLock MAX, you, the HVACR technician can connect refrigerant lines in seconds, boosting efficiency while providing the safety and reliability you expect from Parker.

This post is the second in our series providing answers to the top FAQs on ZoomLock MAX fittings. The answers cover crimping, jaws, tools, and compliance. 

 

Applications

ZoomLock MAX fittings are designed for the following applications:

• Refrigeration

• Air Conditioning

• Heat Pump (Refrigeration Side)

 

Download the full list of FAQs in this handy guide and learn more about ZoomLock MAX.

 

Q: Where do I crimp ZoomLock MAX fittings?

A: Crimp with the jaw straddling directly over the O-ring section of the fitting, as in the image below.

 

Q: How many crimps can you complete on a complete battery charge?

A: That is tool dependent; consult the tool manufacturers owner’s manual.

  Q: How do you know when to service the tool?

A: That is tool dependent; consult the tool manufactures owner’s manual.

  Q: What is the expected life of the jaws?

A: ZoomLock MAX jaws are laser hardened and have a finite life expectancy. We encourage each customer to have the jaws and tools serviced and checked annually or every 10,000 crimps depending on which comes first.

  Q: What tool manufacturers and models are ZoomLock MAX jaws compatible?

A: Please refer to the Press Tool Compatibility table below.

  Q: What is the expected lifetime of the jaws and how do you know when you need to replace the jaws?

A: Check jaws at the latest one year after the purchase or after 10,000 pressings (according to whichever occurs first) by an authorized Rothenberger testing center. Repeat these checks at the latest one year or another 10,000 pressings after the previous inspection. During jaw inspection, check the jaws for operating and functional safety and wear parts (e.g., springs). Functionally and operationally safe jaws are returned.

  Q: Where can replacement batteries and chargers be purchased?

A: That is tool dependent; check the tool manufacturer owner’s manual.

  Q: Can you use ZoomLock MAX to crimp to aluminum, steel, or stainless steel?

A: ZoomLock MAX is designed explicitly for copper to copper connections.

  Q: What standards and codes is ZoomLock MAX compliant with, and what approvals does it hold?

• UL Listed: Refrigerant fitting SA7511.

• UL Listed: Approved use for field and factory installations.

• UL 109 - 7 Pull test is compliant.

• UL 109 - 8 Vibration test is compliant.

• UL 1963 - 79 Tests of Gaskets and Seals used in Refrigerant Systems compliant.

• ISO 5149-2:2014, Refrigerating systems, and heat pumps - Safety and environmental requirements - Part 2: Design, construction, testing, marking and documentation, compliant.

• ISO 5149-2 - 5.3.2.2.3 Strength pressure test is compliant.

• ISO 14903 - 7.4 Tightness test is compliant.

• ISO 14903 - 7.6 Pressure temperature vibration tests (PTV) compliant.

• ISO 14903 - 7.8 Freezing test is compliant.

• ASTM G85 -11 Standard Practice for Modified Salt Spray (Fog) Testing compliant.

• ASHRAE 15 - 2016 Safety Standard for Refrigeration Systems compliant.

• ASME B31.5 - 2016 Refrigeration Piping and Heat Transfer Components compliant.

• 2018, 2015 - 2012, 2009, and 2006 International Mechanical Code (IMC), certified ICC-ES, PMG-1440.

• 2018, 2015, 2012, 2009 and 2006 International Residential Code (IRC), certified ICC-ES, PMG-1440.

• 2018, 2015, 2012, 2009, and 2006 Uniform Mechanical Code (UMC), certified, ICC-ES, PMG-1440.

  Q: Does ZoomLock MAX work on both hard and soft copper?

A: Yes, ZoomLock MAX is a press fitting system for use with hard, half-hard, or annealed copper tube conforming to EN12735-1 or ASTM-B280.

  Q: What is the guarantee on ZoomLock MAX fittings?

A: The product has a 10-year guarantee from the first date of purchase. 

  Q: What is the material used to make the O-ring?

A: Hydrogenated Nitrile Butadiene Rubber (HNBR).

  Q: What is the expected life of the O-ring in the system?

A: The expected life of the O-ring, if used within the product specifications for temperature and pressure, is at least 25 years. The product has a 10-year guarantee from the first date of purchase.

  Q: Are there any storage issues, including where the fittings are stored in vehicles and exposed to extremes of high or low temperature?

A: No, the product is not subject to degradation under normal storage conditions, provided it is kept in original packaging and not exposed to direct sunlight for long periods.

 

The time-saving solution for HVACR technicians and contractors

ZoomLock MAX technology provides a leak-proof connection, eliminating brazing, flames, fire spotters, or risks from installing traditional HVACR fittings. Now, HVACR technicians and contractors can install piping in seconds with NO torch, NO hot work permits, and NO fire safety equipment.

Ready to learn more? Visit the ZoomLock MAX website to download the full FAQs sheet, schedule a demo, watch it in action, get training support, locate a distributor, and get started today!

 

 

 

 

 

 

 

Article contributed by Chris Reeves, product manager, Contaminant Control Products, Sporlan Division of Parker Hannifin. For more information on Parker Sporlan products please visit our website.

 

 

 

 

Related, helpful content for you:

ZoomLock MAX Press-to-Connect Refrigerant Fittings FAQs–Part 1

34 Frequently Asked Questions on the Smart Service Tool Kit

HVACR Tech Tip: Refrigerant Piping Expansion and Contraction

HVACR Tech Tip: Interchangeable Cartridge Style Thermostatic Expansion Valves Save Time & Money

Defining Our Unique Contribution to the World

Parker Sporlan’s ZoomLock MAX press-to-connect refrigerant fittings, designed for the air conditioning and refrigeration markets, allows HVACR contractors to make secure leak-free connections in seconds. That equates to less time on the job and more profit for your business.

ZoomLock MAX provides a clean, leakproof connection for refrigerant lines up to 700 psi. By eliminating concerns about gas and flames, ZoomLock MAX gives you more flexibility in where and when you can work, plus there is no need to nitrogen-purge the lines. This post is the first of three blogs answering your top FAQs on the product.

 

Applications

ZoomLock MAX fittings are designed for the following applications:

• Refrigeration

• Air Conditioning

• Heat Pump (Refrigeration Side)

 

Download the full list of FAQs in this handy guide and learn more about ZoomLock MAX.

 

Q: My jaws sometimes get stuck on the fitting after crimping. What can I do to make it easier to remove the jaws?

A: Applying a thin coating of WD-40 or similar lubricant to the jaw before starting a job should help.

 

Q: Why is it significant that ZoomLock MAX is “UL Listed”?

A: UL Listed provides approval by UL for field and factory installation. UL Recognized products limit products to being factory installed only.

  Q: What is the #1 suggestion to ensure safety?

A: Follow all our steps on prep and installation.

  Q: What is the #1 cause of leaky fittings?

A: Possibly, skipping the prep and installation steps causes the tube to leak.

  Q: What is a “deep” scratch, and how do you clean this?

A: Your fingernail can feel a deep scratch. Try using a new piece of Scotch-Brite abrasive pad. Alternatively, use a 340 grit sandpaper/cloth.

  Q: Can you show an example of a “good” copper tube surface after sanding?

  Q: How do I know the correct insertion depth when pushing the ZoomLock MAX fitting onto the copper tube?

A: Use the depth gauge provided or the Minimum Insertion Depth chart below (Table 1) to determine the correct insertion depth. Mark the tubing with a permanent marker to indicate proper insertion depth on every tube.

  Q: Do you have a solution for crimping onto swaged tubing like that coming out of the condenser and evaporator on residential units?

A: No, we do not have a specific product designed to crimp over the swaged tubing. However, if there are at least 2 inches of straight copper tubing after the flared end and is accessible with the jaws, you may cut the flared end off and crimp directly to the tube. 
 

Q: What is the minimum braze distance from the ZoomLock MAX fitting?

A: See Table 2.

  Q: What is the minimum distance between ZoomLock MAX fittings?

A: See Table 3.

 

Solutions for HVACR technicians and contractors

ZoomLock MAX press-to-connect flame-free refrigerant fittings are popular with HVACR contractors and technicians who are looking for more flexibility, safety, and efficiency. The biggest benefit of that improved efficiency is more productivity and increased profit potential for you!

Visit the ZoomLock MAX website to learn more, get engineering support, locate a distributor near you, and get started today!

 

 

 

 

 

 

 

Article contributed by Chris Reeves, product manager, Contaminant Control Products, Sporlan Division of Parker Hannifin. For more information on Parker Sporlan products please visit our website.

 

 

 

 

 

Related, helpful content for you:

Parker Sporlan Supermarket Seminar Series: Metering Devices, TEVs - Q&A Part 1

Parker Sporlan Supermarket Seminar Series: Metering Devices, TEVs - FAQs Part 2

HVACR Tech Tip: Top 5 FAQs About Thermostatic Expansion Valves (TEVs)

HVACR Tech Tip: Maintaining Refrigerant Flow in Thermostatic Expansion Valves

34 Frequently Asked Questions on the Smart Service Tool Kit

As we introduced our Parker Sporlan webinar series we realized that we couldn't possibly answer all the questions in that short amount of time. We decided to create Climate Control blogs to answer some of the more pressing questions. This is the second of three blogs answering questions from our Supermarket Seminar Series: Metering Devices, TEVs.

 

TEV - Balanced Port Valves

Q: In my experience, balanced port valves can operate at a much lower pressure drop than a standard valve. Is this correct? And why do they work much better at a lower head pressure in the winter?

A: Balanced port valves are typically utilized to neutralize the opening force on a TEV that could be contributed by high side pressure. This comes into consideration with high-pressure refrigerants, like R-410A, and large capacity systems. The Balanced Port does allow the valve to modulate down to approximately 25% of rated valve capacity vs. 30% for a non-balanced or conventional valve. Customers have selected oversized balanced port valves for some applications. This selection technique contributes to the valve's ability to adequately function in winter conditions in the absence of head pressure controls.

Q: What applications require balanced port valves versus internally or externally equalized valves?

A: Balanced port valves are used in many applications ranging from small refrigeration units to large air conditioning systems. Please refer to the previous Question and Answer for more details regarding balanced port valves. Internally equalized valves sample evaporator pressure at the valve's outlet fitting and are suitable for use on systems with low-pressure drop across the evaporator coil. Externally equalized valves sample evaporator pressure at the installation point of the equalizer line. This is typically downstream from the sensing bulb of the Thermostatic Expansion Valve. An externally equalized valve is required if the pressure drop across the evaporator is high or a distributor is fitted in the system.

Q: Are balanced port valves available as either internally or externally equalized? And do they come in larger tonnage for HVAC?

A: Yes, balanced port valves are available as internally equalized and externally equalized versions. Balanced port valves are available in small, fractional tonnage capacities and are available up to 70 tons and more depending upon the refrigerant and the application.

 

TEV - Adjustment

Q: What is the part number of that superheat adjustment tool? This information would be handy for our technicians.

A: The superheat adjustment tool is only available through the Sporlan Store. Please contact your Sporlan Field Sales Engineer for assistance.

Q: Packing nut versus adjustment nut, is this the same item?

A: No, these two items are not the same. Some TEVs are manufactured with a packing nut. The packing nut is used to loosen or tighten the adjustment stem packing material around the adjustment stem. The adjusting stem is used to change the superheat setting of the TEV, and it may be accessed once the seal cap has been removed. If the TEV has a packing nut, it must first be loosened in order to allow the adjustment stem to be easily turned to set superheat. The packing nut must then be retightened to reduce leakage around the adjustment stem. Finally, the seal cap must be reinstalled as the final protective measure against leaks.

Q: Have you had issues with turning the adjustment too far and turning the disc to where it will not allow you to adjust the valve anymore?

A: It is possible to damage the adjustment mechanism on a TEV through abuse by using a wrench that is too large, etc. While this is not common, it can happen. If it does, either replace the valve or replace the adjustable bottom cap assembly.

 

TEV - Thermostatic Charge

Q: When is it recommended to use a ZP thermostatic charge?

A: Use the ZP thermostatic charge for low-temperature refrigeration systems, with evaporator temperatures ranging from 0ᵒF down to -40ᵒF, and when it is necessary to limit evaporator pressure during pulldown.

Q: What is the difference between Z and ZP thermostatic charge?

A: The Z and ZP thermostatic charges have the same low temperature operating range. Use both for evaporators with temperatures ranging from 0ᵒF down to -40ᵒF. However, the ZP has the maximum operating pressure feature built into the thermostatic charge and can limit evaporator pressure during pulldown. The Z thermostatic charge does not include this feature. The Z and ZP thermostatic charges are not intended as replacements, and each serves its own unique purpose.

 

For more information on TEVs see Parker Sporlan Bulletin 10-10-8, Bulletin 10-9, Bulletin 10-10.

For more information on Parker Sporlan products please visit our website.

 

Article contributed by Jim Jansen, senior application engineer, Sporlan Division of Parker Hannifin

 

 

 

 

 

Additional resources on HVACR Tech Tips:

Parker Sporlan Supermarket Seminar Series: Metering Devices, TEVs - Q&A Part 1

HVACR Tech Tip: Understanding and Preventing Superheat Hunting in TEVs

HVACR Tech Tip: Everything You Want to Know About Superheat

Defining Our Unique Contribution to the World

As we introduced our Parker Sporlan webinar series we realized that we couldn't possibly answer all the questions in that short amount of time. We decided to create Climate Control blogs to answer some of the more pressing questions. This is the first of three blogs answering questions from our Supermarket Seminar Series: Metering Devices, TEVs.

 

TEV - Installation

Q: What if you can only mount the sensing bulb on a vertical suction line?

A: There are times when no other option is available. When one of those times happens, go ahead and install the bulb on the vertical suction line; however, this is a compromise. But how about installing an appropriate length of horizontal tubing at the evaporator outlet and before entering the trap for the riser? Now there is adequate room on a free-draining, horizontal length of tubing to install the bulb.

Q: If you must place the bulb on a vertical line. Does it matter how it is oriented, tail up or tail down?

A: Keep in mind, the vertical line is not the preferred location; however, there are times when no other option is available. If the thermostatic charge is a liquid type, the position of the capillary tube makes little to no difference concerning the bulb. If it is the MOP style charge, it might make a difference. If that is the case, it would be best to install the bulb with the capillary tube pointing toward the sky or "tail up" as you have suggested. Then, route the capillary tube so that it is physically above the bulb location and even insulate it as a final precaution.

Q: Should the sensing bulbs or the thermistors, in the case of electrically actuated-electronically controlled expansion valves (EEVs), be insulated on the pipe?

A: Yes, insulating the bulb or thermistor is good practice. This helps reduce external influences on the bulb or thermistor. It also helps to manage condensation.

Q: Do we need to apply thermal mastic between the sensing bulb and the pipe?

A: If you follow Sporlan's recommended installation practices, thermal mastic should not be required.

 

TEV - Internally & Externally Equalized Valves

Q: What is the max evaporator pressure drop before you need an external equalizer?

A: The pressure drop is rather small, in the range of 1 to 3 psid depending upon the refrigerant. Keep in mind, an externally equalized valve is necessary any time a refrigerant distributor is present in the system. One could substitute an externally equalized valve as a replacement for an internally equalized valve in just about any application. You simply need to install the equalizer line appropriately. The reciprocal is not true. If an externally equalized valve is required, an internally equalized version of the valve will not suffice.

Q: Why is the equalizing line connected downstream of the sensing bulb?

A: However unlikely, it is possible for an internal leak to develop in some thermostatic expansion valves (TEVs). In the event of a pushrod seal leak, refrigerant could be introduced into the low side of the system by way of the external equalizer line. This possible leak could influence the operation of the TEV by inadvertently cooling the sensing bulb and thus telling the valve to modulate to a more closed position. Positioning this connection downstream of the sensing bulb minimizes any interaction with the sensing bulb in the event an internal leak does occur in the TEV.

Q: Is the pressure tube typically connected after the distributor and before the coil?

A: If by "pressure tube," you mean the equalizer line, no, it must be installed and connected downstream of the evaporator. And better yet, it should be connected to the suction line downstream of the TEV sensing bulb. The distributor is on the inlet side of the evaporator between the TEV and the evaporator

Q: I've never seen an externally equalized valve with the second tube leaving the TEV. Are they uncommon?

A: No, externally equalized valves are not uncommon at all. In fact, most of the valves that Sporlan manufactures are externally equalized.

Q: Typically, I use an externally equalized valve for 4,000 BTU and up. Is that a correct approach?

A: It is a safe bet to utilize the externally equalized valve for almost any application. If the pressure drop across the evaporator coil is greater than 1 to 3 psid depending upon the system refrigerant, an externally equalized TEV is required. If there is a distributor in the system, an externally equalized valve is required.

For more information on TEVs see Parker Sporlan Bulletin 10-10-8, Bulletin 10-9, Bulletin 10-10.

For more information on Parker Sporlan products please visit our website.

 

Article contributed by Jim Jansen, senior application engineer, Sporlan Division of Parker Hannifin

 

 

 

 

 

Additional resources on HVACR Tech Tips:

HVACR Tech Tip: Understanding and Preventing Superheat Hunting in TEVs

HVACR Tech Tip: Everything You Want to Know About Superheat

HVACR Tech Tip: Where Should the TEV External Equalizer Be Installed?

In a basic vapor-compression refrigeration cycle there are 4 primary components that we need to consider. 

1. Compressor: Compresses low pressure temperature vapor to a high pressure temperature vapor.
2. Condenser: Vapor rejects heat to ambient (air, water, etc.). Vapor condenses to liquid. Pressure constant if no glide.
3. Metering Device: Device has a small orifice, high pressure drop. Liquid changes from 100% liquid to saturated liquid vapor mix with an associated drop in pressure at relatively constant enthalpy.
4. Evaporator: Refrigerant absorbs heat from the refrigerated space. Refrigerant boils/changes phase. This should be 100% vapor at the evaporator outlet.

 

The modern refrigeration system

The modern refrigeration system is advanced and can seem complicated and each one is different. Some installations have multiple/distributed racks throughout the store. Other designs include one or more compressor racks in a mechanical room with split suctions intended to satisfy both low and medium temp refrigerated cases. These systems may include different refrigerants, condenser types, unloading, sub-coolers, heat reclaim and head pressure control.

The condenser is located on the high side of the system and is connected to the discharge line. Installed near the condenser may be heat reclaim and split condenser valves along with head pressure controls. The heat reclaim and split condenser valves are part of a complete head pressure control package.

 

Heat reclaim valve integral

During the refrigeration process, heat is transferred from a place where it is objectionable (like the place you are trying to cool or freeze) to a place where it can be rejected, like the great outdoors. The transferred heat to the ambient can be used for another purpose instead of rejecting it. By utilizing the 3-way heat reclaim valve, the otherwise discarded energy can be redirected to provide supplemental store heat or to preheat water.

When the valve is de-energized, it’s flow exits through the valve to the normal condenser. Note: refrigerant should be bled from the reclaim coil (or the condenser coil in some instances) to the suction side of the system when not in use. 3-Way valves (ex. S12D13B) with internal bleeds can bleed refrigerant from the idle condenser or use an auxiliary solenoid valve, restrictor and check valve as an optional method.

The 3-Way solenoid valve is energized when reclaimed heat is required. This sends refrigerant through the reclamation heat exchanger (the water heater in this case) and then on to the normal condenser. In the series arrangement, the water heater de-superheats the refrigerant and the condensing process occurs in the normal condenser. Refrigerant should not condense in the water heater. In the series arrangement refrigerant always flows through the normal condenser. When the reclaim coil is idle, trapped refrigerant should be bled to the suction to be utilized in the remaining parts of the system. The check valve should be used in the reclaim “pump out” or bleed line whenever the reclaim heat exchanger is exposed to temperatures lower than the saturated suction temperature of the system. This will prevent refrigerant migration to the coldest location in the system which could be the coil.

 

 

When piped in parallel, the heat reclaim coil must be large enough to fully condense the refrigerant on the high side. Because the heat reclaim valve is a solenoid style product, it shifts as opposed to modulates, and 100% of the system refrigerant flow will go to one coil or the other. Remember, the idle coil should be drained of refrigerant either by using an auxiliary solenoid valve or the optional internal bleed feature of the B-version 3-way heat reclaim valve. The B-version is only capable of bleeding one condenser coil back to the suction side. The remaining condenser will need an auxiliary solenoid to bleed refrigerant when that coil is idle.

 

There are three possible malfunctions for a heat reclaim valve:

1. Coil burnout.
2. Failure to shift to reclaim mode.
3. Failure to shift to normal mode.

Coil burnouts are extremely rare unless caused by one of the following:

1. Improper electrical characteristics.
2. Continuous over-voltage, more than 10%.
3. Under-voltage of more than 15%. This applies only if the operating conditions are such that the reduced MOPD causes stalling of the plunger, which results in excessive current draw.
4. Incomplete magnetic circuit due to the omission of the plunger assembly during reassembly.
5. Mechanical interference with movement of plunger which may be caused by a deformed enclosing tube.
6. Coil energized while not installed on a valve.

Failure to shift to reclaim mode:

1. Coil burnout.
2. MOPD greater than specifications.
3. Restricted high pressure pilot connection. Pilot connection requires a 50 psi differential (discharge to suction).
4. May not have allowed sufficient time to pump out the reclaim coil while in the normal mode.

Failure to shift to normal mode:

1. Stray voltage holding plunger up.

2. Restricted, closed service valve, or capped suction connection on pilot.

In addition to these failure modes, dirt or contamination is ultimately one of the biggest system problems that can occur. There may be a possible refrigerant leak causing low receiver level if flash gas is present at the expansion valve outlet. As a temporary fix, you can deactivate the reclaim. If the heat reclaim output is too low, there is likely a head pressure control issue.

For additional information on 3-Way Heat Reclaim Valves, download Parker Sporlan Bulletin 30-20 or visit the product page here. For more information on HVACR products and literature visit Parker.com/Sporlan.

 

HVACR Tech Tip Article contributed by Jason Forshee, application engineer, Sporlan Division of Parker Hannifin

 

 

 

 

 

Additional HVACR Tech Tips helpful for you: 

HVACR Tech Tip: Basic Troubleshooting Given Three Measurements

HVACR Tech Tip: Principles of Thermostatic Expansion Valves

HVACR Tech Tip: Where Should the TEV External Equalizer Be Installed?

What’s changing in HVAC? It might be simpler to ask what isn’t changing.
According to Steve Yurek, the president and CEO of the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), the industry is facing change on all fronts.

1. There’s trade uncertainty due to the imposition of tariffs.
2. A federal government that is unwilling to deal with environmental and energy issues.
3. And rapidly rising temperatures tied to increasing greenhouse gas emissions affecting urban building codes.

And that’s just for starters.

Now add in the level of change contractors and distributors are facing on the job - with new refrigerants, growing automation, complex sensing and monitoring technologies, the advent of smart controls, predictive residential diagnostics, the ongoing push for green buildings, even how contractors are communicating with customers - and perhaps it’s understandable why HVAC professionals seem to be a vanishing breed. In fact, the Bureau of Labor Statistics (BLS) estimates the current HVAC technician shortage at 70,000, with an additional 115,000 new HVAC/R professionals are needed to meet the demand within the next four years.

 

Check out our infographic

 

Download the related white paper, How to Capitalize on HVAC/R Trends to Drive Business Growth and learn what actions contractors and distributors must take now, to capitalize on environmental responsibility trends.

 

 

 

 

 

Read more about this topic:

How Greener Materials and Technologies Are Impacting the HVACR Industry

HVACR Trends in Green Building with GreenStar and LEED

The IoT is Transforming the HVACR Industry--Are Stakeholders Ready?

How to Use Virtual Engineer for HVACR Product Selection

 

 

 

 

 

 

To obtain reliable performance with solenoid valves on refrigeration or air conditioning systems, it demands careful consideration of application requirements during the selection process. Parker Sporlan offers a wide variety of solenoid valve sizes and styles which may be employed in refrigeration and air conditioning systems to electrically control refrigerant flow. Solenoid valves are electrically operated ‘stop-valves’. These are either fully open or fully closed. Remember these do not modulate flow.

Two basic solenoid valve types

Solenoid valves are typically classified according to the stem and plunger action.

1. Direct acting – Energizing the coil directly opens the main port of the valve allowing full flow. A direct acting valve pulls the plunger against inlet pressure and is typically limited to small applications or where there is a low-pressure differential across the valve.
2. Pilot operated – Energizing the coil opens a pilot port which releases pressure above the main disc/piston/diaphragm allowing it to move to an open position for full flow.

A pilot operated valve makes use of pressure differential across the valve to allow for higher flow capacities without the need of a large solenoid coil. A minimum of 1 psi pressure differential is required to allow the disc/piston/diaphragm to return to its normal position. This is THE key statement, without a minimum pressure drop across the valve, once in operation the main port will not return to normal.

 

Why is sizing important?

There has always been a tendency in the industry to select solenoid valves based on line size. However, due to the pressure drop required for proper operation, this policy is risky and not recommended.

In other words, if a liquid line solenoid valve is being selected for a system having 5/8-inch OD liquid line, there is a tendency to select any valve having 5/8 ODF connections. For example, we have 4 valve series with 5/8 OD connection sizes ranging from 6.0 tons to 23 tons. If a capacity of 15 tons is required, choosing solely based on line size can lead to detrimental scenarios.

1. Under-sizing and a starved evaporator.
2. Grossly oversized valve which will not have the minimum 1 psi pressure drop and its disc/piston/diaphragm will NOT return to its normal position.

  Sizing

Choose solenoid valve based on system capacity with a minimum of 1 psi pressure drop. Then choose from available connection sizes. If the desired connection sizes are unavailable, bushings and couplings can be used to adapt to the existing line size, which will NOT affect valve performance.

Example: 15 ton, R410A, Liquid Line Solenoid valve with 5/8 OD connections:

Options:

1. E14, a little over 3 psi pressure drop across the valve and has 5/8 OD option
2. E19, a little over 1 psi pressure drop across the valve only 7/8 OD option

In this example, the E14 would be the best option. The reason is the load on the system may drop thus causing a marginally sized valve to be too big.

For more information on solenoid valves please see Parker Sporlan Bulletin 30-10. For various HVAC and Refrigeration product information and solutions visit www.Parker.com/Sporlan.

 

Article contributed by Henry Papa, sales engineer, Sporlan Division of Parker Hannifin.

 

 

 

 

Additional resources for you:

HVACR Tech Tip: What You Need to Know About Flooded Head Pressure Control

HVACR Tech Tip: Everything You Want to Know About 3-Way Heat Reclaim Valve Applications

HVACR Tech Tip: What is Important in Refrigerant Distributor Performance?

Simple maintenance steps for system reliability

There are simple steps that an HVACR technician can take during their routine spring and fall inspections or at any time when onsite to enhance reliability. The good news is that most of the items listed below are commonly followed for system efficiency and capacity maintenance but also positively affect system reliability. Performing these simple steps greatly enhances the probability that a system will last its full design life.

1. Maintain coil cleanliness. Dirty coils lead to reduced airflow, cooling capacity, efficiency, and increased compressor operating temperatures. One compressor manufacturer told me that overheating compressors is the number 1 cause of compressor failure. Coil cleaning saves on operating costs while enhancing system reliability and avoids unnecessary system downtime and repair costs.
2. Maintain proper charge quantity. Undercharged systems cause the compressor and all system components to work unnecessarily. Low charge also causes higher compressor operating temperatures which lead to failure over time. Properly charged systems run efficiently and cool keeping compressor temperatures low.
3. Fix leaks. Leaks lead to low charge and all the problems discussed in the prior blog Protect Your System During Install With These Steps. In addition, as refrigerant leaks out, moisture and air will enter the system albeit in small quantities. The Catch-All® will protect the system by capturing the moisture, at least until its capacity is fully used. After this, even small intrusions over time leads to oil or refrigerant degradation, corrosion, and other equally bad results.
4. Change the Catch-All filter-drier. During normal operation the Catch-All filter-drier is capturing any water molecules that are in the system components, capturing the wear particles from compressor operation and other particles flushed from components or tubing. In essence, it is similar to the oil filter on your car or truck engine and needs to be replaced on the AC system you are working on. Below are the guidelines for when to replace the Catch-All filter-drier:
   1. Anytime the system is opened. It is not possible to know how much capacity of the Catch-All has been used nor how much contaminants will be added to the system during the repair. Replacing the Catch-All ensures it has sufficient capacity to capture the introduced water and debris and capture the materials normally expected to be generated over time.
   2. Anytime the See-All moisture indicator shows water is present. Water will react and that reaction is always detrimental. The Catch-All capacity has been exceeded and needs replacing.
   3. Anytime the Catch-All pressure drop causes loss of subcooling or 5 psi pressure drop. The Catch-All has captured enough solid debris to cause excessive pressure drop. If the filter-drier is cooler than the inlet side tubing, then subcooling has been lost and the Catch-All needs replacing. The Catch-All, like air filters, need replacing when it has done its job.
   4. Anytime an acid check of the oil shows high acid level. When the TA-1 acid test kit shows high acid, it has surpassed the capability of the Catch-All. It is imperative to replace the Catch-All and remove the acid as quickly as possible before it harms system components. In addition, review the compressor operation to ensure it is not experiencing a slow burnout (internal electrical short) that is turning refrigerant and lubricant into acids, sludge, and solid debris. If a compressor burnout has occurred, follow the clean-up procedure in Parker Sporlan Bulletin 40-10. Below are some of the key steps in this process:
      • Install an oversized liquid line Catch-All to dry the system, capture acid, and solid debris. This protects the TEV from plugging.
      • Install a properly sized suction line Catch-All to rapidly capture acid and solid debris to protect the compressor.
      • Replace the two Catch-Alls until pressure drop of both stops increasing and acid level is satisfactory when checked with the TA-1 acid test kit.
5. After clean-up operation is completed. Once any clean-up is done, replace the liquid line Catch-All with a standard size and remove the suction line unit or replace it. This renews the protection the Catch-All and provides for continued contaminant control. This step is often overlooked.

For more information on sizing filter-driers and system clean-up procedures please see Parker Sporlan Bulletin 40-10. For various HVAC and Refrigeration product information visit www.Parker.com/Sporlan.

 

Article contributed by Glen Steinkoenig, product manager, Contaminant Controls, Sporlan Division of Parker Hannifin.

 

 

 

 

Additional resources for you:

HVACR Tech Tip: How to Apply Filter-Driers on Heat Pumps for System Protection

HVACR Tech Tip: Protect your System During Install With These Steps

HVACR Tech Tip: When Should a Catch-All Filter-Drier be Changed?

In today’s world where time is precious, doing the job right the first time is critical. Your customers want reliability and appreciate the attention to detail that will ensure their system provides cooling or heating when they want it. So how does one minimize the callbacks and warranty servicing on the units they installed or serviced? Using the best contamination control practices is a good starting point.

All HVACR technicians learn the basics when they go through technical school but many of us may have forgotten a few of the not so obvious steps. So, a quick refresher may help you improve the quality of your installations, increase your customer satisfaction and referrals that drive repeat business, growth, and the bottom line.

  Good contamination control starts with the install

1. Keep out debris. There are many opportunities for dirt, solder, flux, copper chips, etc. to be introduced during the installation of the air-conditioning or refrigerating unit. Minimizing the introduction of solid materials is easy by covering the open connections to the system and ensuring tubing and components are free of chips, burrs, caps, etc.

2. Use flushing products correctly. Flush products can be used to clean the tubing and/or coils being reused to remove residual oil, wear particles, burnout residue, etc. Too often a technician will inject the cleaner and then let gravity drain the fluid to the collection device. Most flush systems recommend using pressurized air or nitrogen to blow out all of the liquid. If this step is not completed, much of the flush will remain in the tubing and will eventually evaporate but will leave behind all of the debris that would have been ejected.

3. Install a high performance filter-drier. Many of today’s air-conditioning and heat pump comfort conditioning systems come with a filter-drier, some even come installed. Installing the provided unit only costs a few seconds of braze time and some alloy and gas but will provide the unit with all of the reliability which the system design engineer intended and validated. If the unit did not come with a filter-drier, then installing a properly sized high quality, time proven Catch-All® can ensure contaminants like water, acids, sludges and varnishes are captured before they can react with system materials. These materials may react with compressor windings leading to compressor burnout or cause copper plating which reduces bearing clearances or poor valve seating eventually causing failure. Or they can deposit in the expansion device restricting flow or proper modulation of thermostatic or electric expansion valves. Loss of superheat control can lead to lack of cooling if the evaporator is starved or even worse, flooding of liquid back to the compressor causing bearing washout and eventual compressor failure.

4. Install a See-All® Liquid and Moisture Indicating Sightglass. This is the only device that can provide a real-time look at the worst system contaminant of them all, water. It also indicates if subcooling is present when it is solidly full of liquid or if it has been lost when vapor bubbles are seen. For negligible cost, it enables the technician to quickly see if the refrigerant has excessive water in it, if the filter-drier needs changing, and a quick check of system charge with just a glance.

5. Eliminate brazing scale. During brazing, the hot copper can react with oxygen from the air to form copper oxide. This black flakey scale readily detaches from the tubing wall and is pushed around by the refrigerant clogging fine ports and passages in valves, compressors, etc. wreaking havoc on their functionality. Purging the line with nitrogen stops this reaction and should be an everyday practice. 

6. Evacuate the system prior to charging. Pulling a strong vacuum, 500 microns or per manufacturer's instructions, to remove the air has never been easier. Today’s dual stage vacuum pumps are easily capable of achieving this level of vacuum. This eliminates the air that wants to react as well as ensuring full condenser capacity and reduces compressor work. It will also pull water from the tubing surfaces and other components in the system leaving less highly reactive materials in the closed system.

7. Charge the system properly. A properly charged system will provide the required cooling or heating with the least energy usage and system runtime. Conversely, a low charge will provide less compressor cooling along with poor system capacity/efficiency. Overheating the compressor eventually leads to compressor failure, carbon debris, and sludge-like material formation that will adversely affect the replacement compressor.

8. Clean-up large systems quickly and completely. Large multiple compressor and multiple evaporator systems are much more difficult to assemble without introducing significant solid debris, moisture, and air. Changing the cores in the liquid line shell and using a secondary filter will capture moisture and solid trash quickly and effectively, even down to very small particles. The clean-up is complete when the See-All indicates the system is dry and the cores/filter-elements have been replaced so they can continue to capture generated debris.

 

Follow these steps to ensure reliability

Following these simple steps eliminates many of the reliability-robbing contaminants and provides the ability to monitor and remove any contaminants that made it into the system. In addition, the Catch-All will continue to capture solid debris, sludges, moisture, and acids protecting the TEV and compressor. However, routine maintenance of systems can significantly improve their reliability and should not be neglected. 

For more information on sizing filter-driers and system clean-up procedures please see Parker Sporlan Bulletin 40-10. For various HVAC and Refrigeration product information visit www.Parker.com/Sporlan.

 

 

Article contributed by Glen Steinkoenig, product manager, Contaminant Controls, Sporlan Division of Parker Hannifin.

 

 

 

 

Additional resources for you:

HVACR Tech Tip: How to Apply Filter-Driers on Heat Pumps for System Protection

Use of Suction Line Filter-Driers for HVAC Clean-up After Burnout

HVACR Tech Tip: When Should a Catch-All Filter-Drier be Changed?

Not everyone is familiar with all the intricacies of HVACR as we are at Parker Sporlan and that’s okay. Whenever you have questions, you can always contact our world class Technical Support team or check Parker.com/Sporlan for in-depth information and guidance. Our Climate Control Blog has many of the answers you need for questions on most topics, so dig in. Below, we’ve answered some of the most frequently asked Thermostatic Expansion Valve (TEV) questions – you’ll find easy answers to your need-to-know questions.

  Where should the TEV external equalizer be installed?

The purpose of the external equalizer is to sense the pressure in the suction line AT THE BULB LOCATION and transmit it to the TEV diaphragm. This usually means installing the external equalizer immediately down stream from the bulb. This ensures the correct pressure is signaled to the TEV. In some situations, this “ideal” location may not be possible. In these cases, an alternate location could be used. However, the pressure at these locations must be nearly identical to the pressure in the line where the bulb is located. In other words, alternative locations are acceptable as long as these pressures are essentially the same as when the system is operating at full load. In the past there has been concern about installing the external equalizer “up-stream” from the bulb. This was due to the possibility of refrigerant leaking past the TEV push rods, passing through the equalizer line and into the suction line, thus falsely influencing the TEV bulb temperature. Today, with Parker Sporlan’s TEV design, this possibility is virtually eliminated.

  Where should the TEV’s bulb be located?

In general, the TEV bulb should be installed on a straight section of horizontal suction line. When the compressor is above the evaporator – Locate the bulb on a straight, horizontal line, pitched slightly down, immediately after it leaves the evaporator. A short trap should follow before the vertical line rises to be connected to the compressor suction. With the line pitched down, any liquid refrigerant and/or oil will pass into the trap, away from the bulb. As the trap fills with oil, the velocity of the refrigerant will carry the trapped oil into the vertical section and be returned to the compressor. When the compressor is below the evaporator – No trap is required after the bulb location, but the line should be pitched slightly down to prevent any liquid refrigerant or oil from being trapped at the bulb location. When several evaporators are installed both below and above the common suction line – Observing the same principles outlined above, the piping should be arranged to prevent the accumulation of oil and/or refrigerant at the bulb location. Also, traps installed in the suction lines of evaporators prevent the refrigerant from one evaporator from entering the suction line of another evaporator.

  Should a Parker Sporlan Thermostatic Expansion Valve (TEV) be adjusted after installation?

Before leaving the factory, a specific superheat setting is made on each and every Parker Sporlan TEV. A standard superheat setting has been established for every size and every thermostatic charge. This standard-setting provides the proper superheat on the average system to which the particular TEV size and charge is likely to be applied. Therefore, in most cases, a superheat adjustment on the job will not be necessary. Parker Sporlan recommends a change in the superheat adjustment only after it has been determined that it is required. Careful measurement of the operating superheat, using the recommended procedure, will establish if a change would be beneficial. To reduce the superheat, turn the adjusting stem COUNTERCLOCKWISE. To increase the superheat, turn the adjusting stem CLOCKWISE. When adjusting the valve, make no more than one turn of the stem at a time and observe the change in superheat closely to prevent over-shooting the desired setting. On adjustable TEVs, Parker Sporlan attempts to position the adjusting stem at the half-way point when it is at the standard-setting. This allows maximum adjustment in both directions. Parker Sporlan supplies a number of OEMs with non-adjustable TEVs. The OEM determines the superheat setting through laboratory testing of the unit. Some of these valves can be converted in the field to adjustable models.

  How can I tell if my TEV is adjustable?

Most of the TEVs listed in Parker Sporlan Catalog 201 or Bulletin 10-10 will be adjustable unless there is an “N” stamped in the valve body as part of the nomenclature (i.e. NSVE-5). Many of the valves made specifically for OEM customers are non-adjustable. One way to tell if a valve is adjustable or non-adjustable is to look at the bottom cap. Adjustable expansion valves will have a threaded joint between the valve body and bottom cap as well as a threaded joint between the bottom cap and a hex seal cap that is removable to expose the adjusting stem. Non-adjustable valves, on the other hand, will generally have only one threaded joint between the valve body and bottom cap. An exception to this rule is a factory adjustable valve with two threaded joints and a smooth, round non-removable seal cap. Many non-adjustable valves can be converted to adjustable by changing the bottom cap assembly. Contact Parker Sporlan’s Technical Support department for more information. They will need all the information you can get from the valve’s markings to assist you. CAUTION: Never attempt to determine if a valve is adjustable by removing the bottom cap assembly unless the system has been pumped down, it could result in serious injury.

  Can I replace the powerhead on my Parker Sporlan TEV and how do I know what to get?

With a few exceptions, most Parker Sporlan thermostatic expansion valves manufactured after 1993 have replaceable thermostatic elements. The exceptions are valves with an “H” before the valve nomenclature (i.e. HSVE-10), the now obsolete Platform valves, and the relatively new HX valve. The Platform and HX valves can be identified by a stainless steel element. The valves with the “H” in the nomenclature have had the elements soldered to the valve body at the customer’s request. Parker Sporlan makes replacement element kits that are available through Authorized Sporlan Wholesalers. The thermostatic elements on Parker Sporlan expansion valves are identified by a series of numbers and letters. The number (i.e. 33, 43, 83, etc.) identifies the element size, while the letters (i.e. VGA, RC, JCP, etc.) identify the refrigerant and thermostatic charge. A replacement element kit can be obtained based on that information. For example, a valve with markings on the element of 83 and VCP100 will require a KT-83-VCP100 element kit. (For more information on element identification, consult Bulletin 210-60.) If markings on the element are no longer legible, contact Parker Sporlan’s Technical Support team for help in selecting a replacement element. They will need all the information available from the valve body, and a description of the application. To completely identify a Parker Sporlan thermostatic element the following information is required:

• Element size number

• Refrigerant Thermostatic charge

• MOP (Maximum Operating Pressure) if other than standard E

• Capillary tubing length

• Bulb size if other than standard

For more information on Thermostatic Expansion Valves (TEVs) download a copy of Bulletin 10-10. For more troubleshooting information download a copy of 12 Solutions for Fixing Common TEV Problems - Form 10-143.

 

HVACR Tech Tip Article contributed by Jason Forshee, application engineer,  Sporlan Division of Parker Hannifin

 

 

 

 

 

Additional HVACR Tech Tips helpful for you: 

HVACR Tech Tip: Basic Troubleshooting Given Three Measurements

HVACR Tech Tip: Principles of Thermostatic Expansion Valves

HVACR Tech Tip: Where Should the TEV External Equalizer Be Installed?