Low subcool high superheat

Replace air filters and the blower wheel. Overfeeding of the metering device. Ensure sensing valve of the TXV is properly insulated. Insufficient heat load to the coil. Clean the filters and the coil. Oversized AC system. Consider going for a well Sized AC unit. Read also: How to Fix High Superheat Low Subcooling.

To make the adoption of low-code technology hassle-free, this platform comparison guide covers a lot of basic as well as more advanced information to evaluate the top low-code plat...Fig. 6 compares the heat duty of the two tube surfaces under evaporation dominated conditions (high superheat/low subcooling). It can be seen from the figure that the total heat duty from the porous tubes is greater than that of the plain tubes for the entire solution flow regime. As mentioned earlier, the figure also shows that the sensible ...In this HVAC Video, I Explain Superheat and Subcooling in the Refrigeration Cycle to Understand the Operation Easier! I go over how to understand the importa...The difference of the two temperatures is the subcooling value. Trouble diagnosis Data from superheat and subcooling measurements can be useful for determining various conditions within the HVAC/R system, including the amount of refrigerant charge and verifying the operating condition of the metering device. These measurements can also be used ...the superheat constant. Subcooling involves two measurements as well: one for pressure and one for temperature, but this one is taken from the liquid line. Target subcooling can be found on the system nameplate. The actual subcooling should be within ±3°F of the target subcooling for correct refrigerant charge. An improper superheat value canLow-code is a way to design and develop applications with little or no coding. It empowers users with little to no technical background. * Required Field Your Name: * Your E-Mail: ...Then unit need 3.6lb of refrigerant, charged it and pressures were like this: Low side press: 79psi. High side press: 300psi. Suction tube temp: 89ºf. indoor temp: 75º-77ºf. outside temp: 90º. Cause the superheat was high i tough the evap was starving cause a restriction, so i replaced the liquid line filter, blow the lines w/nitrogene ...

Low pressure due to low refrigerant charge will be accompanied by a warm suction line and a high superheat (see "Checking Superheat"). If the suction pressure is low and superheat is low (cold suction line) DO NOT ADD REFRIGERANT. If the suction pressure is low and the superheat is high try adding refrigerant. If the pressure does not come up ...Subcooling Is The Missing Piece Of The Puzzle. August 14, 2002. In past articles I've written about superheat as a charging and diagnostic tool. There are actually four pieces to the refrigerant system diagnostic puzzle: 1. Suction pressure; 2. High-side pressure; 3.Robo stated it clear, the normal superheat for a residential system can and will vary and some charts go even further than he stated 2-45 degrees. That answer above drives the point, if you do not know the evaporator load, you can not predict the superheat. Reply. 06-02-2011, 06:58 PM #14. hvacvegas.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. Here is a service checklist for a restricted liquid line after the receiver and before the filter drier: ... Compressor superheat: 70°F:Performing subcooling usually creates positive values. In the above example, the subcooling value was positive one. In instances when HVAC systems have negative subcooling values, it is an indication that there will be a move opposite of standard subcooling (or an increase in temperature). When there is a negative subcooling result, there is a ...Low superheat high subcooling is a common issue with AC units. There are 5-6 low superheat causes and 3 high subcooling causes. By comparing these causes, we can see which ones are the reason we have low superheat and high subcooling. Here is a chart of low superheat causes (on the left) and high subcooling causes (on the right). The …R22 and R410a Low Pressure, High Superheat, Refrigerant Charging Problem Explained!, Specifications: Temperature Scale: Celsius Max Working Pressure: 500PSI Burst pressure: 2500PSI Hose Length: Feets (around 36 inches) Couplers: High ... Refrigerant Levels on a Heat Proper Subcool. Charging Refrigerant with Subcooling. R22 And R410A Refrigerant ...Oct 12, 2018 ... When the suction pressure is low, the technician should take the subcooling and superheat inside and outside. ... If the superheat is high, you ...

In order to assure that liquid refrigerant does not return to the compressor during the running cycle, attention must be given to maintaining proper superheat at the compressor suction inlet. Emerson recommends a minimum of 20F (11C) superheat, measured on the suction line 6 inches (152mm) from the suction valve, to prevent liquid refrigerant ...Taking the measurements is useful for any type of system, to identify trouble spots. However, when charging a TXV system, you charge by subcooling. And, when charging a cap-tube system, you charge by superheat. Both types can be charged by weight, if known. Trust, but verify. RSES Certificate Member Specialist.High Superheat and very low/no sub-cooling. I am inspecting an old unit and my superheat is very high like 65° and my sub-cooling is pretty much at 0. The unit is running fine and the homeowner says that she feels cool air coming out the vents inside the house. I am thinking it maybe low refrigerant or maybe there's a leak perhaps?non combustables in system...had to reclaim entire charge ,and recharge to make it work rightHowever, if the approach is low, it can indicate refrigerant restriction when combined with low suction, high superheat, and normal to high subcooling. If the approach value is low with normal to low superheat and normal to high suction pressure and high subcooling, it is an indication of overcharge. (Also, if you want to learn more about using ...If the load is low, the superheat will be low. If the load is high, the superheat will be high. Superheat is sensible heat transfer that provides very little useful cooling. This occurs because there is no change of state; only change of temperature. ... We use the superheat and subcooling levels of an air conditioning system as a measure of ...

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Low Refrigerant charge: Verify Subcooling (15-20 F) and EXV 40-50% open at full load, 12 F superheat; Ratio= EXV % flow command / Superheat Control Compressor Flow estimate > 1.6; Incorrect Setting of Low refrigerant Temp Cutout (IOM). It should be set for type and percent (%) of glycol concentration ... - Water Flow too low- High concentration ...Adjust the superheat of the valve to a slightly higher value. Attempting to control an evaporator near to or lower than 5°F operating superheat can exceed the sensing capability of most expansion valves and result in hunting and subsequent intermittent flooding. If practical, move the bulb farther downstream on the suction line.Example of how to fix a 3 ton 16 SEER AC unit running on R-22 freon that has high superheat and low subcooling: Add R-22 refrigerant (but only after you fix the leak, more below). To simplify this, we can say that: High Superheat = Amount of refrigerant in the evaporator coil is too low. Low Subcooling = Amount of refrigerant in the condenser ...When an evaporator float switch is used in the drain pan of an air conditioner or heat pump, if the drain pan fills up the float will interrupt the low voltage circuit to. the compressor contactor. A system operating with a high superheat and a high subcooling most likely has. A refrigerant restriction.

What causes High Superheat and Low Subcooling Liquid Line Restriction. The refrigerant passes through a liquid line in the HVAC system. The normal flow of the liquid means that you will be able to maintain optimum levels of the refrigerant. However, if there is a restriction or a blockage that restricts the flow, problems will be inevitable.System Information R22 2.5 ton: Low Side: 115. High Side: 240. Return Air: 83. Suction Line Temp: 75. Measured Super heat: 5. Super heat should be around 15. Low superheat is an indication that liquid refrigerant not changing state in the evaporator and is possibly flooding back to the compressor.To check subcooling, attach a thermometer to the liquid line near the condenser. Take the head pressure and convert it to temperature on a temperature/pressure chart. Subtract the two numbers to get the subcooling. For example, 275 psi head pressure on an R-22 system converts to 124°F. The liquid line temperature is 88°F.In this HVAC Video, I Explain Superheat and Subcooling in the Refrigeration Cycle to Understand the Operation Easier! I go over how to understand the importa...This will cause the compressor superheat to be high. The 100 percent saturated vapor point in the evaporator will climb up the evaporator coil, causing high superheats. Low Amp Draw High compressor superheats and low suction pressures cause low-density vapors to enter the compressor.Subcool is about what it should be on an R410a system for comfort cooling. Even on a packaged unit. I'm guessing very low load on the evap side. Or an air restriction. Edit: also it's like high of 50F where I live so I may be more focused on Heating season not cooling season.The following readings were taken on a 87 degree day aproximately 50% humidity with a indoor temperature of 82 degrees. Low pressure 62psi @ 65 degrees superheat=30 degrees, High pressure 330psi @ 90 degrees sub cooling = 40 degees. inside temperature differential aprox 14 degrees.For superheat measurement, we use the blue low side gauge. The red one (high side) is for measuring subcooling on the liquid line. Needless to say, we: Don’t want a very low superheat (0°F, 1°, or 2°F) since this indicates liquid refrigerant might be entering the compressor. The compressor can only handle vapor, not liquid.High superheat and high subcool is usually a indicates an restriction in the refrigeration line. I'm new here, just wanted to grab some knowledge. I'm working with a newer Lennox R410A (13SEER) unit. The call was for not cooling properly. Any help would be great! Your subcooling is 19° and your superheat is 16°.• Superheat for low side • Subcool for high side (TVX) Systems Refrigerants: • R22 • R134a • R404a • R410a 1.800.547.5740 www.ueitest.com ... Thank you for purchasing the UEi SSM1 Superheat/Subcool Meter. Use the SSM1 to measure superheat and subcool by direct connec-tions for temperature and pressure. The SSM1 is programmed with ...

If it does it in decent weather: It's airflow. Or, more accurately a lack of heat load on the evap. Your txv has bogged all the way down, creating a high subcool. It's bogged so far down, and still can't maintain a decent superheat. This is from your low evap temp, low sh and high subcool.

High subcooling is usually accompanied by high head pressure because liquid is displacing available condensing area. Low superheat, low evaporator load - dirty filter, slipping belt, low fan speed, filthy coil. High superheat, evaporators being starved for refrigerant if suction pressure is low. If suction pressure is high and superheat seems ...If you’re on a potassium-restricted diet, it’s important to stick with foods that are going to help you stay on track and feel your best. Learn more about some common foods that ar...And yes, you can have too much subcool, but don't want to since it will, as been talked about before "destroy" the capacity of your system! and will lower the capacity of your condensor. Last edited by Lowrider; 03-03-2007 at 10:05 PM . 04-03-2007, 06:23 AM #15. Gary.4 Using Table 2, select the column which is closest to the measured vapor pressure. 5 Scroll down the column to find your calculated superheat. 6 Read the required vapor line temperature at the intersection. (°F) If the measured vapor line temperature does not agree with the required vapor line. 7 temperature, add refrigerant to lower ...In this HVAC Video, I Show SEVERELY UNDERCHARGED, UNDERCHARGED, CORRECTLY CHARGED, and OVERCHARGED Scenarios on a Running R-410A Refrigerant Air Conditioner ...Superheat is checked by measuring the temperature of the vapor line, measuring the pressure, then subtracting the saturated temperature from the measured temperature. In the case of a blend, you Simply read the saturated temperature next to the pressure in the vapor (dew point) column of the chart. When checking the subcool condition the ...Superheat is high. How is charge? Low. Subcool is low. How is charge? Low. Comp amps are low. How is charge? Low. Delta T is low. How is charge? ... How is charge? Over. Superheat is high. How is charge? Over. Subcool is high. How is charge? Students also viewed. Abbréviation Autorisation ATC. 88 terms. alexmblanchet. Pubs Test Review. 31 ...4. Low Subcooling Caused Poor Compression (Potential Compressor Problem) 1. Low Refrigerant Charge (Low Subcooling) Or High Refrigerant Charge (High Subcooling) The most common cause for non-normal subcooling is a wrong refrigerant charge. If the system is overcharged (too much freon), we will get high subcooling.First, measure the superheat right at the evaporator outlet in the same general location as the TXV bulb and equalizer. In most cases, the superheat at that point should be 5-10 degrees, but refer to the manufacturer's specs when in doubt. In some cases, you will not have a pressure port at the evaporator, so you must rely on a …

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Low subcooling for R22. Low subcooling usually means your system is undercharged or has a dirty evaporator coil. It's like running your car with low tire pressure - it won't perform well. The solution? Add refrigerant or clean the coil, depending on the issue. High subcooling for R22. High subcooling often indicates overcharging or a ...23. Post Likes. In low ambient conditions the reason the subcooling rises so much is because it starts to stack in the condenser. The reason for this is refrigerant is attracted to the coldest place in the system. During the winter the ambient conditions get below the temperature at the evaporator causing the refrigerant to naturally want to ...Jul 8, 2022 · High superheat low subcooling is when there is a limited flow of refrigerant in the evaporator and a limited flow of the refrigerant in the condenser. It is worth noting that in systems with liquid line receivers, subcooling will not increase because the liquid will go to the receiver instead of the condenser although the receive line filter is ... proper low- and high-side pressures, set superheat and subcooling temperatures, and to set pressure controls. The tempera-ture glide of a blend will determine how the PT chart will look. Therefore, a quick review of tem-perature glide from last month's arti-cle is necessary: • As a portion of a refrigerant blend works its way down the lengthHigh superheat and high subcool is usually a indicates an restriction in the refrigeration line. Reply . 06-04-2014, 11:19 PM #5. hvacrmedic. View Profile ... Your pressures seem to be a bit low for 410. Try charging to 130(L) and 325-330(H). Reply . 06-05-2014, 11:51 AM #12. gravity. View Profile View Forum PostsA low delta T may also be an indicator of low charge. The telltale signs are a low condensing temperature, low evaporator temperature, low subcooling, and high superheat. To get the most accurate readings, you should ensure that there are NO airflow restrictions and that the Schrader cores have been depressed if you take your readings with gauges.In this video, I show how a Liquid Line Restriction Affects The Liquid Pressure and Subcooling. I go over the indicators of a Restriction such as vapor satur...High superheat low subcooling on a TXV system means that there is no sufficient amount of refrigerant in the evaporator and there is low amount of the refrigerant in the condenser unit. This condition is mainly caused by low charge in an air conditioning system and can be fixed by sealing leaks and adequately charging the system with a refrigerant.If the load is low, the superheat will be low. If the load is high, the superheat will be high. Superheat is sensible heat transfer that provides very little useful cooling. This occurs because there is no change of state; only change of temperature. ... We use the superheat and subcooling levels of an air conditioning system as a measure of ...A low subcooling and a high superheat. An air conditioner with a fixed restriction metering device is operating with an evaporator saturation temperature of 40 degrees Fahrenheit and a suction line temperature of 42 degrees Fahrenheit. The factory specified superheat for the current operating condition is 12 degrees Fahrenheit.Low sub cool low superheat 1st stage Trane. I am working with a 4TWA7036A3000 matched with a TAM9A0C36V31DAB, using a 2 stage thermostat. Commercial building with AHU mounted horizontal in the ceiling of the ground floor and heat pump on the roof, with a 50' line set and a 24' rise. Upon start up system was charged in 2nd stage cooling and ...By Martin King Posted December 9, 2022. In this HVAC Video, I Explain Superheat and Subcooling in the Refrigeration Cycle to Understand the Operation Easier! I go over how to understand the importance of both Superheat and Subcooling. I go over the refrigeration cycle, where superheat is found and what will happen if a Piston or capillary tube ... ….

Good Subcooling Value for R-410A: Similar to superheat, the ideal subcooling value for R-410A can vary depending on factors like system design and operating conditions. However, a common target for R-410A systems is to achieve a subcooling value in the range of 8 to 15 degrees Fahrenheit (°F) or approximately 4.4 to 8.3 degrees Celsius (°C).Subcooling. The term subcooling (also called undercooling) refers to a liquid existing at a temperature below its normal boiling point. For example, water boils at 373 K; at room temperature (293 K) liquid water is termed "subcooled". A subcooled liquid is the convenient state in which, say, refrigerants may undergo the remaining stages of a ...Subcooling is beneficial because it prevents the liquid refrigerant from changing to a gas before it gets to the evaporator. Pressure drops in the liquid piping and vertical risers can reduce the refrigerant pressure to the point where it will boil or "flash" in the liquid line. This change of phase causes the refrigerant to absorb heat before ...A low subcooling and a high superheat. An air conditioner with a fixed restriction metering device is operating with an evaporator saturation temperature of 40 degrees Fahrenheit and a suction line temperature of 42 degrees Fahrenheit. The factory specified superheat for the current operating condition is 12 degrees Fahrenheit.When it comes to building a deck, you want to make sure you have the best materials available. Lowes is one of the top retailers for decking supplies, offering a wide selection of ...R134a Low Subcooling, High Superheat. This is regarding the refrigeration system for a water cooler. The evaporator is immersed in the water to be cooled. The following information is available at 25 mins after starting the compressor: When water temperature was 7.8 deg. C. Evaporator Inlet: 0.7 deg. C. Suction: 23 deg. C. Discharge: 72.6 deg. C.1. Check Refrigerant Pressures. Hook-up refrigerant gauges to the pressure ports on the unit. Blue --> "True Suction" Low Pressure. Red --> High Pressure (Small liquid line) Allow the unit to run for 5-10 minutes. Monitor pressures as the system operates. Normal R-22 Suction Pressure = 60 - 80psig. 2.Low Superheat Low Subcooling: Learn To Fix It. Low superheat and low subcooling are the indicators for your evaporator to be low on heat and have a limited refrigerator in its condenser. We will recommend you maintain a suitable climate around your Living area in order to feel comfortable. Tom Moore May 19, 2023 — 5 minutes read.To measure liquid subcooling: 1. Attach your gauge manifold to the liquid line service port. If you use a quick-connect fitting on the end of your hose, make sure it's a low-loss fitting. I've seen some quick-connect fittings that allow pressure loss, which can cause inaccuracies in the charging procedure. Low subcool high superheat, 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. ... Evaporator superheat: 40°F: Compressor superheat: ... All of the liquid in the condenser will probably sit there for a while and subcool because …, If I have my theroy right I have a low superheat of 10 and a high subcooling of 21. Ambiant temp outside is 81 and all temps are in F. 19-07-2011, 03:16 AM #40., Lots of people saying check airflow, but low airflow cannot lead to high superheat. The refrigerant is entering the evaporator at 23°, but it's 70° by the time it leaves. What is warming it up, if not airflow? The only realistic way to have both high superheat and low subcool is low charge., A. Turn on the system. B. Turn off the system. C. Adjust the system to a neutral position. D. Have a cylinder approved by the DOT nearby. ANS: B. Capacitors should be shorted with a _____ before checking with an ohmmeter. 20,000 ohm Resistor. The high- and low-side pressures on an operating air-conditioning system can be converted to the ..., To measure liquid subcooling: 1. Attach your gauge manifold to the liquid line service port. If you use a quick-connect fitting on the end of your hose, make sure it's a low-loss fitting. I've seen some quick-connect fittings that allow pressure loss, which can cause inaccuracies in the charging procedure., Texas is a great place to live, but it can be expensive to buy a home. Fortunately, there are ways to find a low-cost home in the Lone Star State. Here are some tips to help you fi..., If superheat is low and sub-cooling is high: Charge must be adjusted. System overcharged If superheat is high and sub-cooling is high: Could have blockage in coil, orifice or line set. If superheat is low and sub-cooling is low: Orifice could be too big, there is no orifice in the unit of the orifice is stuck and refrigerant is by-passing it., May 19, 2023 · Low Superheat Low Subcooling: Learn To Fix It. Low superheat and low subcooling are the indicators for your evaporator to be low on heat and have a limited refrigerator in its condenser. We will recommend you maintain a suitable climate around your Living area in order to feel comfortable. Tom Moore May 19, 2023 — 5 minutes read. , Calculating superheat can tell us how far liquid Freon is traveling through an evaporator coil. If superheat is too high, there's less liquid and more gas in the coil. This can cause overheating. If superheat is too low, more liquid and less gas are in the coil. This can cause flooding and damage in the compressor., This is important because, in cool mode, a dirty air filter caused low airflow on the evaporator. In those cases, you would typically notice a low suction pressure and a low superheat. In heat mode, a dirty air filter causes low airflow across the condenser. That can cause extremely high head pressure. In heat mode, a dirty outdoor coil can ..., Are you in need of home improvement supplies but don’t have the time to visit your local Lowe’s store? Look no further than the convenience of ordering online from Lowe’s. With jus..., The unit is 8 years old. Indoor temp= 81, RH=68. Outdoor temp=93. Suction press=65 (should be 38F), Actual suction temp=81F same as room. Superheat=81-38=43 High. Discharge press=350, (should be 143F) Actual temp=130F. Subcool=143-130=13 Normal. Compressor amps rated at 22, pulling only 18., High superheat refers to a value of superheat that's higher than recommended. As an example: If a system with a target superheat of 10deg is running a 28deg superheat, it has a high superheat. Superheat is the difference between the suction line temperature and the suction saturation temperature, so it's a subtraction of those two numbers. IE:, Ferguson HVAC is a national distributor of residential and commercial heating and cooling equipment, parts and supplies. HVAC contractors across the country rely on us for the best unitary and ductless equipment brands and for a wide-range of HVAC products including accessories, controls, air distribution supplies, and service and repair parts., Apr 22, 2024 · Many manufacturers recommend a subcooling range of 10° – 15°F, but always refer to manufacturer instructions to be sure. Just as there are two kinds of superheat, there are also two kinds of subcooling. They are condenser subcooling and total subcooling. We usually measure subcooling at the liquid line service valve. , Sep 20, 2012 · Low subcooling means that a condenser is almost empty. High subcooling means that a condenser is over field of liquid. 1) The amount of refrigerant entering the metering orifice is the Outdoor Dry bulb. 2) The total heat of the air entering the evaporator coil is the Indoor Wet bulb. With 95 degrees outside air. , Maryland. Posts. 9. Post Likes. Low Subcooling Low Superheat? I am working on a two stage heat pump with a varable speed air handler. The system runs about 1.5 deg S/C and about 2 deg S/H The delta T is 22 deg. A capacity check shows systems is operation at 122% of publish Capacity. Adding refregerant does not change the S/C much at all., Grab the two approximate outdoor temps from the chart, then just use the 2 rows of pressures and temps along with the indoor wet bulb temp. Study with Quizlet and memorize flashcards containing terms like What is the operational range for the superheat and subcool?, When the Superheat is below the operational range, is it overcharged or ..., Subcool low and Superheat high I had a new goodman heat pump 410a 15 seer and air handler unit installed last week. The installer had overcharged it the first time and had to return to cool the compressor and remove coolant. I dont feel it is working as it should after research on the proper method to ensure the superheat and subcool are within ..., If I have my theroy right I have a low superheat of 10 and a high subcooling of 21. Ambiant temp outside is 81 and all temps are in F. 19-07-2011, 03:16 AM #40. Gary. View Profile View Forum Posts View Blog Entries Visit Homepage View Articles VIP Poster Join Date Apr 2001 Location New Port Richey, Florida - USA ..., In short, high discharge temp can commonly be caused by: Low charge (high suction superheat, low suction pressure, low subcool) Severe overcharge. Low condenser airflow. Restricted metering devices. Other restrictions (liquid line drier, suction line drier, kinked lines, clogged screens) Low discharge line temp can be caused by., Calculating superheat can tell us how far liquid Freon is traveling through an evaporator coil. If superheat is too high, there's less liquid and more gas in the coil. This can cause overheating. If superheat is too low, more liquid and less gas are in the coil. This can cause flooding and damage in the compressor., High side pressure and subcool become the determining factor in charging because of the TXVs ability to change flow rate. Superheat still can be measured though to determine if a TXV is operating properly. Some TXVs can be manually adjusted to change spring pressure and flow rate. ... Low Charge- If refrigerant charge is low, the …, I come back the next day expecting to have to pull charge out and the subcool being way high. The unit cooled the house down to 70 it's probably 85 outside. These are my readings 296psi high side, 95.8 lstat, 93.6 line temp, 2.3 subcool. 140.6psi low side, 50.1 vstat, 51.3 line temp, 1.2 superheat. 20degree delta tee across the return and supply., Boiling stones are pieces of mineral put in a solution and heated in a round-bottomed flask so that boiling will be even. Without boiling stones, liquids heated in such flasks have..., What causes low superheat and high subcooling? Because these readings are normal, the low suction pressure is caused by insufficient heat getting to the evaporator rather than low refrigerant. CAUSE #2: A faulty, plugged-in, or undersized metering device is to blame. As refrigerant is added to TXV systems with high superheat, double-check the ..., 2 low pressures with high superheat and low Subcool is a sign of what problem? Dirty Coil, Overcharged. Undercharged. Charged Properly. Overcharged. 48 of 54. Term. What are the 4 major components? Saturation temperature. Radiation. Conduction. Evaporator, condenser, compressor and metering device., Apr 22, 2024 · Troubleshooting Using Superheat and Subcooling Data. Low superheat: Indicates too much refrigerant in the evaporator, likely due to overcharging. High superheat: Suggests too little refrigerant in the evaporator, which may be caused by low refrigerant levels, insufficient heat reaching the evaporator, or a dirty/defective metering device. , Subcooling. To understand superheat or subcooling we must first understand Saturation. Saturation. #1 Pressure (PSIG) converted to a Saturated temperature. Suction saturated is the Blue, low pressure, suction gauge pressure converted to a vapor/ Dewpoint/ suction saturated temperature. Liquid Saturated is the Red, high pressure, head pressure ..., actual superheat is too high, add refrigerant. If it's too low, evacuate refrigerant. Subcooling is the difference between the boiling point of the refrigerant in the condenser and the actual temperature of the refrigerant as it leaves the condenser. The degrees that the refrigerant "cools down" below the boiling point is the subcooling., System Information R22 2.5 ton: Low Side: 115. High Side: 240. Return Air: 83. Suction Line Temp: 75. Measured Super heat: 5. Super heat should be around 15. Low superheat is an indication that liquid refrigerant not changing state in the evaporator and is possibly flooding back to the compressor., The difference between high and low viscosity is the thickness of the material being measured. Low viscosity refers to substances that are thin, such as water, while high viscosity..., September 14, 2001. The dire ramifications of under- and overcharging an air conditioner or heat pump were covered last month ("Using the Superheat Method to Charge A/C Systems,"The News, Aug. 13, page 1). The first installment also contained a basic explanation of what superheat is and what it tells you about the condition of the evaporator coil.