Because discharge gases have leaked through the rings and into the crankcase, the suction pressure will also be higher than normal. The resulting symptom will be a lower head pressure with a higher suction pressure. The symptoms for worn rings on a compressor are very similar to leaky valves.The typical 410a pressures on a 95 degree day are as follows; Liquid pressure: 296.4 psi. Vapor pressure: 295.5 psi. See all other pressures for R410 on different temperatures of the day from -49°F to 150°F below.Because discharge gases have leaked through the rings and into the crankcase, the suction pressure will also be higher than normal. The resulting symptom will be a lower head pressure with a higher suction pressure. The symptoms for worn rings on a compressor are very similar to leaky valves.Watch on. Compression ratio is the ratio of head pressure to suction pressure in an HVAC/R unit. Generally, compression ratios approach 2.5:1 on high-efficiency, 16+ SEER A/C systems. The highest compression ratio in A/C compressors is typically 11:1. Refrigeration compression ratios tend to be quite a bit higher (up to 26:1). low head pressure generally causes insufficient refrig-erant to be fed to the evaporator. 2. Any system using hot gas for defrost or compressor capacity control must have a normal head pressure to operate properly. In either case failure to have sufficient head pressure will result in low suction pressure and/or iced evaporator coils. I have a heat pump with very low pressure on the suction side. I put a new thermastatic control valve thinking the valve my not be working. I still have very low pressure side( Pressure is 10-15 with normal at 45) Evaporator is new with sensing bulb properly installed. I noticed evaporator freezing although the blower is working.By contacting an HVAC technician, you can get your AC system’s suction pressure back to normal levels. If you are experiencing a problem with your air conditioning or heating call us at 512-336-1431 to schedule an appointment. We’ll be glad to come out and take a look at the issue. 1431-183 A/C & Heating proudly serves Round …By contacting an HVAC technician, you can get your AC system’s suction pressure back to normal levels. If you are experiencing a problem with your air conditioning or heating call us at 512-336-1431 to schedule an appointment. We’ll be glad to come out and take a look at the issue. 1431-183 A/C & Heating proudly serves Round …KITCO NEWS -- Gold slightly pressured Tuesday, and iiTrader’s senior strategist Bill Baruch says it's because of the downward pressure lower copper and crude prices are having ...The yen weakened past 150 to the dollar Thursday, adding pressure on officials to intervene in the markets to shore up the currency. Jump to The Japanese yen weakened to above 150 ...Working for a micromanaging boss can feel like being in an unhealthy relationship, but you don't have to cringe in fear or keep your head low hoping that you don't attract their at...What is the normal suction pressure for adults?-100 to -120 mmHg. 11. What is the normal suction pressure for peds?-80 to -100 mmHg ... What are the contraindications of suctioning? Occluded nasal passages, nasal bleeding, epiglottis or croup, acute head face or neck injury, bleeding disorder, laryngospasm, irritable airway, and upper ...The children who would most benefit from quality early education are also the ones who tend to miss school the most. But there's a silver lining. Head Start, the childcare program ...Head pressure: 400 lbs. Condenser air in: 140º F. I guess Condenser air out: what; about 160º F. I am guessing? LSC is: 30º F. - so the system has plenty of refrigerant in it Suction Pressure: 105 lbs. Suction Line Temp: 65º F. SSH: 30º - so the evaporator does not have enough refrigerant in it. What am I missing? PHM-----low head pressure generally causes insufficient refrig-erant to be fed to the evaporator. 2. Any system using hot gas for defrost or compressor capacity control must have a normal head pressure to operate properly. In either case failure to have sufficient head pressure will result in low suction pressure and/or iced evaporator coils.im in the field 3 years now and this is the first time ive come across this. residential split system 1.5 tons and i had a good suction pressure but my head …While many of us may have become comfortable with this “new normal” during the pandemic, it can seem overwhelming to head back outside with regions beginning to reopen.Terms in this set (24) When a redfrigeration systems's suction line is noticeably cold instead of just being cool, it probably contains___refrigerent. low-pressure liquid. When a refrigeration systems's liquid linw is noticably hot instead of just being warm. probably contains ____ refrigerant. high-pressure vapor. At an absolute pressure of 101.3 kN/m 2 (normal atmosphere) the boiling starts at 100 o C. Net Positive Suction Head - NPSH. The Net Positive Suction Head - NPSH - can be defined as. the difference between the Suction Head, and; the Liquids Vapor Head; and can be expressed as. NPSH = h s - h v (3) or, by combining (1) and (2) Restriction in the Refrigerant Flow. Another cause of low suction pressure high head pressure can be a restriction in the refrigerant flow. This can be caused by a blockage in the refrigerant lines or a problem with the compressor, and can lead to low suction pressure and high head pressure. 3. Faulty Compressor.Feb 8, 2023 · The normal operating pressure for R-404A in a freezer at a temperature of 70 degrees Fahrenheit and a suction temperature of 30 degrees Fahrenheit would be around 9.6 psi. The low pressure should be 18-20 psi while the high pressure should be around 200 psi. However, this can vary depending on the specific conditions of the freezer and the ... I've done a few new installs lately. residential splits, r22 and normal conditions say 80 degrees and not humid. when charging the units i was getting a good suction pressure, around 68-70psi, the ...They seem low, check pressure at the compressor, unless there's a long distance between the evap and the cond unit it should get you close enough. your pressures are low, 200-225/55-60 would be closer 90* SCT would be 200psig and 25* SST would be 60ish ... with 175 head 50 box temp i would expect suction to be low 30s to 20s. ice …It's tempting to head to the Caribbean this winter but here's why you might want to avoid the trip -- even to islands with low COVID-19 infection rates. Editor’s note: This post ha...With a TXV 'all' of these situation/conditions will have normal suction pressure: Overcharged ... SH normal; SC high; amps high; RH control/normal. Of the 3 causes 'only' overcharge has a higher than normal subcooling; that's its distinctive differentiating clue. Dirty condenser or low condenser airflow; SH & SC norm; amps high; RH control/norm.it is. Turned it on again. Head pressure starts at 250 suction pressure at max. Sucks down to about 90 on suction side but you can see it struggling to get to 90. It keeps going back to 100. Discharge gets down to 200 and condenser fan shuts of. Then pressure rise to 250 head pressure then fan comes back on.Glad I am positive on what it is.An inefficient compressor is usually indicated by a _____ head pressure and _____ suction pressure. Lower than normal, higher than normal. It is desirable for refrigerant in the suction line tube to be slightly superheated in order to. Insure liquid refrigerant does not enter the compressor.My suction is running at 45psi and head is at 110psi. I checked evap coil and filter and both were clean, so I figured it was low on R22. I added 7 lbs. (factory charge is 7.25 lbs) and pressures did not change. The suction line is frosting up to the compressor. I'm starting to think I have a bad reversing valve.224. Post Likes. Ambient is pretty low. From my experience you should be around 130-150 psi and 14-18 psi when box is at 38 and ambient is between 80-95 degrees. If this unit is going to be in a hot restaurant kitchen I would definitely try to …In the cooling mode, running in outdoor temperatures below 55 degree without a "low ambient control' will cause symptoms very similar to low refrigerant. The cold outside air will cause the head pressure to drop which, in-turn, causes the suction pressure to drop. Try blocking part of the outdoor fan discharge to increase head pressure. Heating.Do it until all the pressure from the low side AC is out before disconnecting everything you used. e. Disconnect the Compressor. Now, after releasing the pressure from the low side AC, disconnect the line connecting the low-pressure side of the compressor to the suction line. Finally, open the valves.Article ID: 64. Last updated: 16 May, 2017. Cooling. Re: Low Suction Pressure. A heat pump or air conditioner runs with a lower-than-normal suction …Restriction in the Refrigerant Flow. Another cause of low suction pressure high head pressure can be a restriction in the refrigerant flow. This can be caused by a blockage in the refrigerant lines or a problem with the compressor, and can lead to low suction pressure and high head pressure. 3. Faulty Compressor.R134a Pressure Chart for Refrigerators, Prep Tables & More. bytechtownadmin. R134a refrigerant is an ethane-based hydrofluorocarbon used in a wide variety of refrigeration equipment, HVAC units and cars. Used as a primary replacement for R12 refrigerant, R134a refrigerant is considered a safe option because it has non-toxic and non-flammable ...The system actually works fairly well even on hot days, its just 2-3 degrees off the thermostat setting. The suction pressure is 95 PSI, about 28 degrees, but the superheat is normal, at 10. The liquid line pressure is fine, the outside coil is clean and the subcooling is 10, which is what the manufacturer calls for.Low suction/low head pressures. Bevearage air Prep table not cooling-. R134a, AEA4440YXA hermetic. pressures were about what they should be for a cap tube system (roughly 150/25 psi) but just blowing around warm air. Plate said 7 oz of R134A but I pull out 2 lbs so I evacuate and recharge with 7oz and now the pressures are way down.This will cause the following symptoms: Low evaporator (suction) pressure; High evaporator and compressor superheats; Low compressor amp draw; Short-cycling on the low-pressure control; Somewhat high discharge temperature; Low condensing (head) pressure; Low condenser split; and.There are three main reasons why a compressor will simultaneously have a low head pressure and a high suction pressure: 1. Bad (leaky) compressor valves; 2. …What should my normal operating pressures on 410a systems be? R410a suction pressure may be around 120psi, and R410a head pressure may be anywhere from 225psi to 350psi. Many conditions could apply here, there’s absolutely ‘no’ set point pressure for 410a, r22, or anything else. Educate yourself on whats going on in the heat transfer process.Although cryptos enjoyed strong performances earlier, a lack of fundamental catalysts may apply some pressure on the sector. The fiat alternative narrative isn’t quite panning out ...Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. If the system is continuing to cool it may be doing so at reduced capacity, observed as a loss of up to ten degrees of temperature drop across the coil.Suction pressure is on the low side; it pulls refrigerant into the compressor. Head Pressure: Pushes refrigerant through. Suction Pressure: Pulls it back for compression. This push …The typical 410a pressures on a 95 degree day are as follows; Liquid pressure: 296.4 psi. Vapor pressure: 295.5 psi. See all other pressures for R410 on different temperatures of the day from -49°F to 150°F below.This will cause low suction pressures, high superheats, low amp draws, and low head pressures. Also, the symptoms of a restricted TXV system are very similar to a system with a refrigerant undercharge. However, the undercharged system will have low subcooling levels. ... Normal evaporator (suction) pressure. High superheats. Low amp draw.be very nearly equal on both LP and HP gauges. The actual static pressure will depend on the ambient temperature. To ensure it is on the right level, refer to a static pressures table applicable for R134A refrigerant (N.B. not shown on this poster). A low static pressure means a too low system charge, indicating a leak that must be found and ...Efficiency Ratio (EER) is similar to that of R-22. Discharge pressure is only slightly higher and suction pressure is only slightly lower than R-22, so in most cases, existing system pressure settings can be used. While the existing Thermal Expansion Valve (TEV) sizing and power head can be used with R-438A, the slightly lower suctionOften, liquid refrigerant will accumulate in the bottom of the condenser and receiver, and condenser subcooling readings will be normal to high because of this. The system will have symptoms of low suction pressures, high evaporator and compressor superheats, normal to high condenser subcooling, low compressor amp draws, and low head pressures.How to Fix Low Suction Pressure Issues. If there is excessive moisture in system: replace the drier. If you find a flattened or kinked hose: replace the hose. If the compressor pistons have worn out: replace the compressor. If there is a shortage of refrigerant: add refrigerant. If there is a leaking compressor head gasket: replace the head gasket.Number 2 is incorrect, metering device part depends on system to system. High load is correct. Look at your liquid line temps, subcooling and approach temps. They will help diagnose high head issues. There is another cause of high head pressure, mismatched (higher btu) compressor. Different refrigerant in the system.Mar 9, 2022 ... Supermarket Refrigeration-High Suction & Head Pressure Troubleshoot on call(Bad motor and subcooler). Gendron HVAC-R•15K views · 31:38. Go to ...How to Check Subcooling. Attach the thermometer to the liquid line. This time, near the condenser. Then take the head pressure in Psi and convert it to the temperature on the pressure/temperature chart. Assuming you are dealing with a R22 system, let’s say the head pressure is 260Psi. This will convert to 120F.While a blood pressure of 120/80 is normal for people over 18, for those under age 18, normal is based on a percentile rating for the teen’s age, height and gender, according to Ki...One of the leading causes of low suction pressure is refrigerant leakage. When refrigerant leaks occur, the system's refrigerant charge decreases, resulting in reduced pressure levels. Leaks can occur at various points, including connections, joints, valves, or even within the coils themselves. 2. Dirty Evaporator or Condenser Coils.Luckily, there is a pressure instrument that can detect whether or not your head pressure exceeds the normal range and is too high. Head pressure is okay as long as it isn’t outside the normal range. If a high head pressure is detected, you will need to call your local professionally licensed air conditioning service team. What Determines ...Our diagnostic sheet shows that liquid line restrictions cause low suction pressure and normal to low head pressure, not high head pressure. That’s because the compressor requires refrigerant of a specific density to pump refrigerant into the high side of the system; when the suction pressure is low, the compressor can’t move as much ... To diagnose a bad TXV, look for: Low evaporator pressure. High evaporator and compressor superheats. Low compressor amp draw. Short cycling on the low-pressure control. Higher than normal discharge temperatures. Low condensing pressure. Low condenser split. Normal to high condenser subcooling. Jul 8, 2019 · High Suction Pressure R-410a. i went to check an 3.5 ton a/c brand is a ICP (international comfort products) Model WAPL424A1, not cooling my pressures were low side 185 to 190 and high side was around 350 on a 107F hot day. It has a piston as a metering device and compressor was running at 11.50 amps and RLA is 17.25 amps. NPSHr —The net positive suction head required is the measurement of the amount of fluid pressure energy required by the pump. The NPSH available to the pump should be more than what the pump requires. If there is not enough NPSHa, the pump will cavitate. As a result, the performance and reliability can be compromised. In an even …What should my normal operating pressures on 410a systems be? R410a suction pressure may be around 120psi, and R410a head pressure may be anywhere from 225psi to 350psi. Many conditions could apply here, there’s absolutely ‘no’ set point pressure for 410a, r22, or anything else. Educate yourself on whats going on in the heat transfer …By Bryan Orr. September 26, 2022. Share this Tech Tip: Every now and then, a tech will call me and give me the same story of woe. They're working on a system and have the …You are showing low head. Look at it this way. If everything is working properly you would have 8°-12° SC and 10°-20° SH. So lets look at just the SH side first. …Feb 8, 2023 · The normal operating pressure for R-404A in a freezer at a temperature of 70 degrees Fahrenheit and a suction temperature of 30 degrees Fahrenheit would be around 9.6 psi. The low pressure should be 18-20 psi while the high pressure should be around 200 psi. However, this can vary depending on the specific conditions of the freezer and the ... I have a heat pump with very low pressure on the suction side. I put a new thermastatic control valve thinking the valve my not be working. I still have very low pressure side( Pressure is 10-15 with normal at 45) Evaporator is new with sensing bulb properly installed. I noticed evaporator freezing although the blower is working.Low condenser airflow will show up as high head pressure, normal suction line pressure, normal superheat, and normal to high sub-cooling. See details at SUPERHEAT …307. Post Likes. Low suction/low head pressures. Bevearage air Prep table not cooling- R134a, AEA4440YXA hermetic. pressures were about what they should be …High suction and low head does not bode well for the compressor. ... Non condensables will raise head pressure, because they don't condense. ... didnt check wet bulb, but condensate draining so close to normal couldnt tell a difference. Reply . 07-26-2011, 09:13 AM #16. Mr Bill. View Profile View Forum Posts View Forum Threads ...I have a suction pressure of 70, converted temp of 41, suction line temp of 51, head pressure of 250, converted temp of 117, head line temp of 96. Air entering condenser is 82 and exit is 100. Air entering evaporator is 76 and exiting is 52.Low Side Pressure (Suction Pressure) 110-140 psi: 70-140 psi: High Side Pressure (Condensing Pressure) 300-350 psi: 250-400 psi: The above pressure range is based on the following operating conditions. ... Sometimes, improper brazing work may not cause a leak during normal days when the mini split working pressure is low.Posted: 7/6/2012 2:35:12 PM EDT. My HVAC contractor recently saw head pressure of 350-400, normal to low suction. He diagnosed it as a restriction in the condensor coil, replaced condensing unit. The "changeout team" that installed the condenser saw exactly the same situation on the new unit. They left and now waiting for a re-evaluation from ...So we replace the compressor (same model #), replace the liquid line filter dryer, and evacuate to 500 microns. I weigh the charge in per the manual = unit's orignal charge + addl ounces per foot of lineset - total of 5# 6 oz. Start unit up, damn it, looks wrong immediatelY: Suction: 149.5 psi. Suction Temp: 55.4*F. HIGH SUCTION PRESSURE / LOW HEAD PRESSURE ISSUE. Hey guys, need some help i am working on a carrier
The fact that these readings are normal indicates the low suction pressure is not caused by low refrigerant, but insufficient heat getting to the evaporator. CAUSE … The normal operating pressures for R404A in a walk-in cooler typically range between 55-70 psi on the low side and 210-250 psi on the high side. However, these pressures can vary based on the specific application and ambient conditions. Feb 26, 2023 · Step 4: What’s a Normal Pool Pump Pressure? Normal pool pump pressure can vary depending on your pool’s size and the specific pool pump you have installed. However, most pools have a normal pressure range of 10-20 PSI. If your pressure falls outside this range, you may need to adjust your pool pump settings or seek professional help. You are showing low head. Look at it this way. If everything is working properly you would have 8°-12° SC and 10°-20° SH. So lets look at just the SH side first. What causes high SH, low on charge or a restriction. 8° SC would discount the low on refrigerant right. That leaves a restriction.In a 2-ton capillary tube system, the unit does not develop full capacity. Heat pressure is low and suction pressure is high. What is the problem?Read also: R410a Pressure Chart High and Low Side. psi: Pound per square inch, unit of pressure. FAQ What is the normal suction pressure on a 404a walk in the freezer? The normal suction pressure on a 404 a walk in freezer is around 10-20 psig (10 is ideal) on the suction side if working properly. And the high side is about 180 or so.are serviceable by a manufacturer-approved repair facility will lead to compressor inefficiency may cause high suction pressure and low head pressure Correct! All of the above. A suction line may also contain a ____. ... If a condenser has high head pressure and a higher than normal temperature, a technician could ____. ...If the suction pressure is low and the suction line is warm, the system has a _____ evaporator. flooded. starved. ... the suction and discharge pressure will both be higher than normal. 33 of 104. ... air may be circulated through the condenser and cause A. high head pressure B. low head pressure C. low compressor discharge line temperatures D ...By contacting an HVAC technician, you can get your AC system’s suction pressure back to normal levels. If you are experiencing a problem with your air conditioning or heating call us at 512-336-1431 to schedule an appointment. We’ll be glad to come out and take a look at the issue. 1431-183 A/C & Heating proudly serves Round …First, we must be aware that a restriction exists in the first place. In the case of the most common liquid line restrictions on HVAC equipment (with no receiver), we will see low suction pressure, high superheat, and normal to high subcooling. (Note: high head pressure isn't typically an indicator of a restriction!) In those cases, we know ...What is a chiller low-pressure alarm fault? A low-pressure fault in a chiller plant means that the inlet pressure of the compressor is too low, causing the low-pressure protection relay to act. The normal compressor suction pressure of a room temperature chiller should be 0.3~0.45 Mpa and the protection value is set at 0.2 Mpa. The dangers …Aug 28, 2012 · Gonzo, if your evap was dirty you would have a low suction and low superheat. Not dirty evap let that go. High suction low head, with 100 lb suc and 100 degree ambient your head should be quite a bit higher. Really need the amp draw of comp and rated RLA but appears to be a compressor issue. Suction pressure is on the low side; it pulls refrigerant into the compressor. Head Pressure: Pushes refrigerant through. Suction Pressure: Pulls it back for compression. This push …Do it until all the pressure from the low side AC is out before disconnecting everything you used. e. Disconnect the Compressor. Now, after releasing the pressure from the low side AC, disconnect the line connecting the low-pressure side of the compressor to the suction line. Finally, open the valves.HIGH SUCTION PRESSURE / LOW HEAD PRESSURE ISSUE. Hey guys, need some help i am working on a carrier unit with a Scroll Compressor. I am getting 80 …When it comes to upgrading your shower experience, one of the key factors to consider is water pressure. If you’re looking for a high-pressure shower, you might be torn between cho...Head on 410 at 100° will be in the 375 - 400 range depending on surrounding conditions, sun, heat load inside, dirt on the coil. high suction pressure could be from a high load, bad compressor, bad-wrong-nonexistant metering device. There are a multitude of things that can cause pressures to be high or low depending on the situation.Hypertension is characterized by high blood pressure, and it’s an important risk factor for heart disease. It’s a modifiable risk factor, which means you can make lifestyle changes...1 Answer. Hi, High head and a low suction pressure can indicate a couple of different things. One, condenser coil very dirty and needs to be washed very well. This will bring your head pressure down but let it run back up to normal engine temperatures. If the head is ok after you clean it, and suction is even lower, you may still be low on charge.I've done a few new installs lately. residential splits, r22 and normal conditions say 80 degrees and not humid. when charging the units i was getting a good suction pressure, around 68-70psi, the ...Jul 10, 2014 · With a TXV 'all' of these situation/conditions will have normal suction pressure: Overcharged ... SH normal; SC high; amps high; RH control/normal. Of the 3 causes 'only' overcharge has a higher than normal subcooling; that's its distinctive differentiating clue. Dirty condenser or low condenser airflow; SH & SC norm; amps high; RH control/norm. What is a chiller low-pressure alarm fault? A low-pressure fault in a chiller plant means that the inlet pressure of the compressor is too low, causing the low-pressure protection relay to act. The normal compressor suction pressure of a room temperature chiller should be 0.3~0.45 Mpa and the protection value is set at 0.2 Mpa. The dangers …How to Fix Low Suction Pressure Issues. If there is excessive moisture in system: replace the drier. If you find a flattened or kinked hose: replace the hose. If the compressor pistons have worn out: replace the compressor. If there is a shortage of refrigerant: add refrigerant. If there is a leaking compressor head gasket: replace the head gasket. Below we list a dozen causes of high head pressure in an air conditioner or heat pump compressor motor. Of these, debris clogging or malfunctioning TXVs seem to be the most common problems. Air contamination in the refrigerant system. Air flow blocked across the condensing coil. Low condenser airflow will show up as high head pressure, normal ... Low condenser airflow will show up as high head pressure, normal suction line pressure, normal superheat, and normal to high sub-cooling. See details at SUPERHEAT …If a TXV receiver system is restricted in the liquid line, most of the refrigerant will accumulate in the receiver, with a bit in the condenser. This will cause low …Low suction/low head pressures. Bevearage air Prep table not cooling-. R134a, AEA4440YXA hermetic. pressures were about what they should be for a cap tube system (roughly 150/25 psi) but just blowing around warm air. Plate said 7 oz of R134A but I pull out 2 lbs so I evacuate and recharge with 7oz and now the pressures are way down.Both fans working fine. Good air flow through evaporator and condenser. There are no leaks, and no icing. I have tried adjusting the charge to raise the low side pressure, but in doing so would also raise the high side exponentially. (i.e. Increase the suction pressure by 20 psi, and the head pressure would jump as much as 150 psi)Often, liquid refrigerant will accumulate in the bottom of the condenser and receiver, and condenser subcooling readings will be normal to high because of this. The system will have symptoms of low suction pressures, high evaporator and compressor superheats, normal to high condenser subcooling, low compressor amp draws, and low head pressures.Study with Quizlet and memorize flashcards containing terms like In a 2-ton capillary tube system, the unit does not develop full capacity. Heat pressure is low and suction pressure is high. What is the problem?, In a 2-ton capillary tube system, the unit does not develop full capacity. Head pressure is high, suction pressure is high, and there is no superheat. What is the problem?, Will the ...The system will now have a normal evaporator superheat of about 5° to 10°F. These normal evaporator superheat readings will only occur with low heat loads on the evaporator. If a capillary tube system is overcharged, it will back up the excess liquid in the condenser, causing high head pressures because of no receiver in the system.These liquid-line restrictions all cause the evaporator, compressor, and condenser to be starved of refrigerant. This will cause …A blockage causes high head pressure while suction pressure remains low. This imbalance puts strain on the compressor and reduces cooling efficiency. To troubleshoot, technicians will check for dirty filters, malfunctioning expansion valves, and debris in condenser coils. Clearing these blockages restores proper function to the …NPSHr —The net positive suction head required is the measurement of the amount of fluid pressure energy required by the pump. The NPSH available to the pump should be more than what the pump requires. If there is not enough NPSHa, the pump will cavitate. As a result, the performance and reliability can be compromised. In an even …The most common causes of pressure in the head and face include allergies, ear infections, the common cold, muscle tension, sinusitis, stress and tension headaches. Increased intra...When dealing with a refrigeration system, the symptoms of low suction pressure, low head pressure, high/normal superheat, and high sub-cooling can indicate a number of potential issues. The correct answer would be restricted metering device.My suction is running at 45psi and head is at 110psi. I checked evap coil and filter and both were clean, so I figured it was low on R22. I added 7 lbs. (factory charge is 7.25 lbs) and pressures did not change. The suction line is frosting up to the compressor. I'm starting to think I have a bad reversing valve.Some times high head pressure like your 390 psi due to dirty condenser, can mask a low charge scenario. The high head leads to poor heat rejection and the higher pressures can force more of the available refrigerant into the evaporator and show up as normal or high suction pressure with normal or low superheat. If this is so always evaporating above zero, 4 or 5 deg celcius, R407c will have