Low subcool low superheat

CAUSE #2: Defective, plugged, or undersized metering device. Let's say a system has 45 psi suction pressure (converts to 22 ° F) and 68 ° F suction line temperature, the superheat is 46 ° F (68 minus 22). This indicates low refrigerant in the evaporator. However, before adding refrigerant, check the subcooling to be sure the problem isn't ...

SUPERHEAT/SUBCOOL CALCULATOR with Thermometer and P/T Chart (69196) OPERATING STEPS. 1. Press the power button. For SuperHeat or Low Side PT Data. Suction Line “Super Heat” Match low side manifold gauge reading (suction pressure) 2. Use the and to display the desired refrigerant. 3. Press ENTER. For SubCool or High …When the subcool is set at 8C, the cooling capacity of DME is 6.5% lower than R134a but the COP is 2.6% higher. Another important finding in this study is that the best performance of DME over R134a is obtained at low subcool and low superheat.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. ... However, the undercharged system will have low condenser subcooling levels. Service technicians often confuse an undercharged system with a restricted metering device.The low Pressure gauge (blue) is used to calculate superheat. A superheat reading of 10F measured at the evaporator outlet, would indicate that the refrigerant at that location is in what condition.. The refrigerant is a vapor (gas).Evap would show a higher suction pressure but low superheat due to flooded condition. shophound Okay, but not releevant to my statements. udarrell The reversing valve can be ruled out easily because if it was leaking discharge gas to suction, there would be a greater heat rejection load imposed on the outdoor coil, reducing …

r22 problem is low superheat. unit found frozen all the way back to the compressor. after everything melted i started the unit up . following measurements : low side 59psi . high side 150psi. room temp db 70.5 f. 54 f wb. supply temp at the diffuser 44 f. condenser outside temp 69 f. getting a super heat 3 and subcooling 7.5 .An additional check of charge can be done by monitoring EXV Percent Flow Command and Superheat Control Compressor Flow Estimate in Kestrelview for the respective circuit. When properly charged, the ratio of EXV Percent Flow Command/Superheat Control Compressor Flow Estimate should be 1. If the ratio is 1.5 or greater, suspect low refrigerant chargeSubcooling is a temperature below saturated pressure-temperature (Table 1). Subcooling is a measurement of how much liquid is in the condenser. In air conditioning, it is important to measure subcooling because the longer the liquid stays in the condenser, the greater the sensible (visible) heat loss. Low subcooling means that a condenser is empty.From the Goodman manual for that model. Outside drybulb 95F inside drybulb 80F. Hi pressure = 335 Psig, Lo pressure 130 Psig. Which is 20-30 psi off on both. But I was under the assumption if it where low on 410a there would be high superheat and high subcooling. Like I said I’m new. With the excessive subcooling and no superheat, I am confused.Subcooling is when the liquid refrigerant in your is colder than the minimum temperature required to keep it from boiling. This can happen when the system is first turned on, or if there's a problem with the system. When this happens, the liquid refrigerant can change from a liquid to a gas phase, which can cause problems with the HVAC system.

A network storage device is one of the best ways to keep your data backed up, but it can be a little pricey to set up and leaving a computer on all the time sucks a lot of power. I...Aug 12, 2019 · On traditional HVAC/R systems, which utilize mechanical metering devices such as a TXV or cap tube, the superheat heating will vary between 8 °F to 20 °F. On newer systems, which use electronic expansion valves and solid state controllers, it is possible to see the superheat setting as low as 5 °F to 10 °F. Aug 11, 2016 · No subcooling and no superheat usually means it's flooding, which does point to the evap side of the system. Orfice/txv , airflow most obvious to check first. Reply. 08-14-2016, 04:53 PM #15. smee123. Regular Guest. Join Date. LOW SUPERHEAT LOW SUBCOOLING TXV. Low superheat indicates that there is an excess amount of refrigerant in the evaporator, or the heat load is not sufficient to vaporize the liquid refrigerant to vapor before it moves to the compressor resulting in compressor damage. Plugging of the evaporator coils can also result in low superheat.High superheat means there's a lot of refrigerant vapor, while low superheat means there's almost none. In a properly operating system, you should have cool vapor leaving the evaporator that moves through the suction line, service valve, and into the compressor. ... It's easy to misdiagnose superheat and subcooling readings when you're ...high superheat/low subcooling = low charge low superheat/high subcooling = high charge high superheat/ high subcooling = refrigerant or airflow restriction. seen that before Reply . 07-17-2011, 01:06 AM #7. Cooked. View Profile View Forum Posts View Forum Threads Professional Member* Join Date Jun 2011 Location Houston area ...

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Are you planning a special event but worried about the cost of renting a banquet hall? Look no further. In this ultimate guide, we will provide you with all the information you nee...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.Added about 15 ounces of refrigerant but no change to subcooling. Contractor's Assistant: Anything else we should know to help you best? It's an R-410a system. Outdoor temp was 80 degrees at condenser; liquid line measured temp. was 86 degrees; high side pressure was 267 psi; low side pressure was 125 psi.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.25. PeterDonis said: The superheat goes up when you add refrigerant because the system is overcharged. The superheat going up when you add refrigerant is telling you that the system is overcharged. My apologies. I did not know that you were saying that the superheat went up because the system is overcharged.The difference between a low-context and a high-context culture lies in the mode of communication that takes place at the individual dialogue level. In low-context cultures, such a...

Subcooling should be 5-18 degrees, with higher values when the equipment has a TXV. Always refer to the manufacturer's specifications for accurate measurements. Troubleshooting Using Superheat and Subcooling Data. Low superheat: Indicates too much refrigerant in the evaporator, likely due to overcharging.That's because low charge results in high superheat AND low subcooling (we have covered this in high superheat low subcooling issues here). We are left with only 2-3 culprits that can actually cause both high superheat and normal subcooling. These are: Too high indoor CFMs. Too high indoor load. Faulty measurement. Let's look at all these 3 ...The high outdoor temps will probably always skew things a bit giving low superheat and low subcool. You're gonna have to learn to get the system in the best range possible for those really hot outdoor ambients! Reasonable head pressure, reasonable suction pressure and enough superheat to keep the compressor happy. It's gotta be tough!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 ...Checking superheat will indicate if the low suction is caused by insufficient heat getting to the evaporator. To check superheat: 1. Attach a thermometer designed to …What is the primary reason for running the suction and liquid lines in physical contact with one another? (A) Separate oil from the refrigerant in the suction line. (B) Reduce installation cost. (C) Superheat liquid refrigerant before the expansion valve. (D) Sub-cool the refrigerant in the liquid line.Low charge and liquid line restrictions are the two main caused of a starving evaporator. Low charge is pretty easy to determine as both the high and low side pressures will be low, with high super heat and low subcooling. A liquid line restriction is typically accompanied by a "flooded" condenser, sometimes called "stacking;" in which the high ...Low Superheat = Flooded Evaporator Sub Cooling is telling you what is going on in the condenser. High Sub Cooling = Flooded Condenser Low Sub Cooling = Starved Condenser To Determine Delta T (Temperature difference across the coil): 1. While unit is running take the temperature of the air in the supply plenum near the coil (approx 12Bryan with HVAC School goes over AC pressures, subcooling, and superheat in his troubleshooting mindset presentation from the BTrained HVAC training event in Birmingham, AL. Bryan also talks a bit about his educational photo-sharing app, MechPic. The suction pressure and suction saturation give us an idea of the refrigerant’s …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.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 …A TEV with a dead power element will operate: A) With a low superheat. B) With a higher-than-normal evaporator pressure. C) Correctly until an adjustment is made to the valve. D) With a high superheat. ... High suction pressure,superheat, and low subcooling. Low suction pressure, low super heat and low subcooling. Low suction pressure, high ...

Jun 7, 2012 · Liquid Pressure 160 Liquid Line Temp 86. Outdoor dB 82. Indoor wB 68. With those conditions it should have around 18 Superheat, Subcooling varies but, needs to be at least 3-F, with those conditions I'd say, at least 6 to 10-F Subcooling. Okay, with LOW: suction, head pressure, SH, SC, & compressor amp draw.

Well, 304-psig is 96-F SCT, therefore the suction line would have to be 89-F to get 7-F subcooling. A 156-psig is 55-F SST, a 56-F suction line would be around 1-F superheat. Many heat pumps use 10 to even 7-F TXV superheat. Appears beenthere nailed it, you appear to be using the pressure saturation temps.HVAC superheat measures the difference between the vaporized refrigerant's temperature and its saturation temperature. The saturation point, or boiling point, describes when the liquid refrigerant turns to vapor. Saturation occurs when there is a high level of heat and moisture in the air. The evaporator coil turns this moisture into a gas ...Low subcooling and high superheat are both conditions that can occur in a refrigeration system and indicate a problem with the system’s balance. Low subcooling means that there is an insufficient amount of refrigerant in the condenser, which is the part of the system where the refrigerant releases the heat it has absorbed from the evaporator.The increase in temperature above saturation is described as the refrigerant’s superheat value. For example, at 18.42 psig, R-134a has a saturation temperature of 20°F. If its measured temperature is 30°F, the refrigerant is said to be superheated by 10°F. One useful area to measure the refrigerant’s superheated value is at the exit of ...Evap would show a higher suction pressure but low superheat due to flooded condition. shophound Okay, but not releevant to my statements. udarrell The reversing valve can be ruled out easily because if it was leaking discharge gas to suction, there would be a greater heat rejection load imposed on the outdoor coil, reducing …In short, measuring superheat and subcooling is like having an insurance policy against big repair bills. And who doesn’t want that? Impact and Causes of High Superheat and Low Subcooling Potential Damages from Abnormal Levels. Ever noticed your HVAC acting a bit strange? It could be due to high superheat or low subcooling levels.Subcooling: It’s the process of cooling refrigerant below its saturation temperature. Subcooling increases the efficiency of your HVAC system by making sure the refrigerant is fully condensed before it enters the evaporator. Superheat: This is when the refrigerant gets heated above its boiling point. Superheat prevents liquid refrigerant from ...

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Study with Quizlet and memorize flashcards containing terms like Refrigerant in the evaporator: a. Changes from a vapor to liquid b. Changes from a liquid to a vapor c. Stays in the vapor state d. Stays in the liquid state, What does a high evaporator superheat indicate?, A low evaporator superheat indicates: a. Undercharge b. System restriction c. Overcharge d. Dirt buildup e. Overcharge and ...Screw compressor discharge superheat. The screw compressor is a special type of compressor for particular applications. The discharge superheat is always lower in the screw compressor than the reciprocating compressor due to low discharge temperature. In a screw compressor, the oil is injected into the compressor; the oil cools the system.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.D. a liquid and a solid. D. The greater the difference in temperature between the evaporator and the air being cooled, ______________. A. the less moisture will be removed from the air. B. the less moisture will be added to the air. C. the more moisture will be added to the air. D. the more moisture will be removed from the air.163K subscribers in the HVAC community. A subreddit for Heating, Ventilation, & Air Conditioning Technicians. If you are not a member of the trade…Low super heat, low subcool. Recovered some refrigerant out to reach target subcool but head pressure/superheat didn't get anywhere I wanted to. A/c was installed a month ago and charge was dialed in before leaving. Any ideas before I call tech support guy.never had this problemIn an operating refrigeration circuit with a low side pressure of 120-psig and a low side line temperature of 50 degrees we have created 10 degrees of super-heat. This is important because super-heat is a measurement of metering. Without the ability to measure the metering of refrigerant in a circuit or the amount of heat being absorbed we ...Bryan with HVAC School goes over AC pressures, subcooling, and superheat in his troubleshooting mindset presentation from the BTrained HVAC training event in Birmingham, AL. Bryan also talks a bit about his educational photo-sharing app, MechPic. The suction pressure and suction saturation give us an idea of the refrigerant’s boiling temperature.A system with low superheat and high subcooling has too much refrigerant. The two previous conditions we looked at had high superheat. Low superheat shows too much refrigerant in the evaporator, and it cannot boil it off fast enough. The excess refrigerant could easily make it back to the compressor and cause permanent damage …The nucleate boiling suppression factor, S, is the ratio of the effective superheat to wall superheat. It accounts for decreased boiling heat transfer because the effective superheat across the boundary layer is less than the superheat based on wall temperature. The two-phase multiplier, F, is a function of the Martinelli parameter χ tt.Superheat and subcooling are two important concepts in HVAC. Superheat is the number of degrees a vapor is above its boiling point at a specific pressure. Subcooling, on the other hand, is the number of degrees a liquid is below its freezing point at a specific pressure. ... Conversely, if the superheat is too low, it could mean that the ...Take the condensing temperature and the condenser outlet temperature, and the difference between the two is the amount of subcooling. "Let's say the condensing temperature is 100°F. Put a thermistor on the condenser outlet, and let's say that's 90°," continued Tomczyk. "So, you have 10° of subcooling. Technicians get confused ... ….

Overcharging a fixed orifice system will have much more effect on superheat and it will go very low the point of compressor slugging. These are the reasons why we need to use subcool to charge correctly on a txv system and use superheat to charge correctly on a fixed metering device system.Sep 23, 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. Superheat and Subcooling are technical readings in an HVAC that measure the Freon (refrigerant) reading. Superheat measures the Freon boiling point in gas form while subcooling measures the Freon in liquid form below the evaporation level. To calculate superheat and subcooling measurements, a specific Mathematical chart is used, and the process ... In summary, here are the seven symptoms or telltale signs of a system low on refrigerant: Medium to high discharge temperatures; High evaporator superheat; High compressor superheat; Low condenser subcooling; Low compressor amps; Low evaporator temperatures and pressures; and. Low condensing temperatures and pressures. Publication date: 7/2/2018.non-condensables in the system. Check the "liquid line subcooling" of the system. The "liquid line subcooling" should normally be 7 to 12° F on a 95° F day. If needed, turn fans OFF to approximately duplicate these conditions in colder ambients. If high subcooling is noted along with bubbles in the sight glass, there are non ...The compressor superheat is the sum of the evaporator superheat and vapour line or suction line superheat. The range of low side pressure for the R404 is nearby 20 psig in the usual case, and the inlet temperature of the compressor is 25° C approx.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 lengthNote: The unit will not display a negative superheat or subcool temperature. "--" will display instead. Make sure you have the proper temperature clamp location (Step 4) and the proper pressure value (Step 5). Suction Line Liquid Line Match low side manifold gauge reading (suction pressure) "Super Heat" "Sub Cool"Superheat is calculated as the difference between the saturation temperature of a substance and the actual temperature of the gas. 3 When it comes to HVAC, refrigerants often boil at much lower temperatures than water. For example, if a liquid refrigerant boils at -10 degrees and is then heated up to -5 degrees, it has been superheated by 5 ... Low subcool low superheat, Aug 29, 2016 · 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 unit is a 3 1/2 Ton heat pump. Original problem was the Evap froze up. Went there and sure enough it was low on charge. TXV equipped. 410A. Data label is calling for a 14 subcool. I put the gauges on and I’m showing a 2. I use a Fieldpiece sman4. I end up putting 15lbs of 410 in and eventually get it to a 12 subcool. Everything is …, Subcooling is a measurement of how much the liquid in the condenser cools down before exiting. When the hot gas in the condenser first turns to liquid, its temperature is at the saturation point. This means that the temperature of the liquid as it first forms is at the same temperature at which the refrigerant is condensing — the saturation ..., In this HVAC Training Video, I Explain Why we need to Measure the Refrigerant Charge with Subcooling when a TXV Metering Device is used. I Explain why the To..., 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 can, 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., 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. Superheat is telling you what is going on in the evaporator. High Superheat = Starved Evaporator Low Superheat = Flooded Evaporator Sub Cooling is telling you what is going on in the ..., High superheat means there's a lot of refrigerant vapor, while low superheat means there's almost none. In a properly operating system, you should have cool vapor leaving the evaporator that moves through the suction line, service valve, and into the compressor. ... It's easy to misdiagnose superheat and subcooling readings when you're ..., To use our two examples from the previous paragraph, R134a at 0 psig and -5 F has 10 degrees of superheat, and the same refrigerant at the same pressure but at -20 F has 5 degrees of subcooling. These concepts of saturation, superheat, and subcooling are the foundation of all sealed system troubleshooting., If your filter drier was plugged you would have low suction pressure and high superheat. This looks like something is going on internally and stopping your compressor from moving gas. ... When you have a receiver it's normal to have very low subcooling readings between 1 and 3 degrees. This more looks to be low compression if everything he ..., 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. Superheat is telling you what is going on in the evaporator., Bumping is an occurrence in chemistry where liquids boiled in a test tube superheat before undergoing a sudden release of vapor, expelling the liquid from the container. Bumping is..., In this HVAC Training Video, I show How to Add R-410A into a Running Air Conditioner that is Very Low on Refrigerant. I Show the Step by Step Procedure for C..., High subcooling shows that the condensing point is occuring earlier in the condenser while low subcooling shows that the condensing point is later in the condenser. Subcooling is used to charge systems with a TXV. Now you can see why knowing what, and why, superheat and subcooling are essential to proper diagnostics and troubleshooting., The superheat value can indicate various system problems including a clogged filter drier, undercharge, overcharge, faulty metering device, restricted airflow, or improper fan motor or blower direction. Suction line superheat is a good place to start diagnosis because a low reading suggests that liquid refrigerant may be reaching the compressor., I had posted in a previous thread about the superheat reading taken on my system being about 11 *F too low (possible overcharge). Today another tech came out and measured everything again. This tech measured the subcooling as well this time. Here are the measurements he took: OAT DB: 68 *F Low side: 68 psi (39 *F) High side: 140 psi (78 *F) High side line temp: 71.7 *F Subcooling: 7 *F ..., Refrigerant undercharge: When there is not enough refrigerant in the system, it can result in low suction pressure, low head pressure, high superheat, and high sub-cool. Restriction in the refrigerant line: A physical blockage in the refrigerant line can cause reduced suction and head pressure, as well as imbalances in the system., The superheat value can indicate various system problems including a clogged filter drier, undercharge, overcharge, faulty metering device, restricted airflow, or improper fan motor or blower direction. Suction line superheat is a good place to start diagnosis because a low reading suggests that liquid refrigerant may be reaching the compressor., High Subcool Low Superheat. Hi I own two wonderful Trane wethertron heat pumps"8 seer". 85 degree day 115 condensing temp. Low side was 65 psig High side 240 psig. 6.5 superheat and 25 degree subcooling. My first assumption was overcharge due to poor winter performance energizing aux heat strips a lot. Right now in cooling I have a 17 …, LOW SIDE SYSTEM TEMPERATURES AND PRESSURES Refrigerant State T, ºF R-410A, psig Superheat/Subcool Low Pressure Saturated 45 131.1 Low Pressure Superheated Vapor 53 131.1 Superheat = T - T sat = 53º - 45º = 8ºF High Pressure Gas 180 448.2 High Pressure Saturated 125 448.2 High Pressure Liquid 110 448.2 Subcool = T sat, This was a call on a walk in freezer that was not getting cold enough, i found that the expansion valve was not working properly and caused the superheat to ..., We use low side blue gauge to measure actual superheat. If this superheat is higher than the target superheat by 2°F or more, we have high superheat (that needs fixing). Example: Let’s say we have a 3-ton 16 SEER air conditioner that runs on R-410A refrigerant (on a 80-degree). We measure that the actual superheat is 17°F., High superheat with a normal subcooling occurs in a refrigeration or air conditioning system when the refrigerant vapor leaving the evaporator is heated to a temperature above its saturation temperature at the given pressure.The causes of high superheat can include: Low refrigerant charge: If the refrigerant charge is low, the evaporator may not have enough refrigerant to absorb heat efficiently., A low suction superheat does not 'indicate' an overcharge. Low suction superheat is the result of too much refrigerant in the evaporator for the heating loading of the evaporator at that moment in time. Post the startup report data: Outdoor Ambient temperature. Condenser air temp in. Condenser air temp out., although the cooling capacity is 4.5% lower. When the subcool is set at 8 C, the cooling capacity of DME is 6.5% lower than R134a but the COP is 2.6% higher. Another important finding in this study is that the best performance of DME over R134a is obtained at low subcool and low superheat. 1 Introduction, 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., Subcooling. Subcooling is the temperature below the condensing temperature of a substance. The condenser in an air conditioner is designed to reject the heat absorbed in the evaporator and added by the compressor. In the condenser, the refrigerant is condensed from vapour to liquid. The process is essentially the reverse of what is happening in ..., non combustables in system...had to reclaim entire charge ,and recharge to make it work right, 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 length, No subcooling and no superheat usually means it's flooding, which does point to the evap side of the system. Orfice/txv , airflow most obvious to check first. Reply. 08-14-2016, 04:53 PM #15. smee123. Regular Guest. Join Date., Jan 13, 2023 · 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. , High superheat, low subcooling—or high subcooling, low superheat—can tell us a story about the system and its needs. Ensuring that a system is fully operational within the appropriate ranges means that you need the right tools to read subcooling and superheat temperatures., 162. 25. I know that having both high superheat and low subcooling on an Air-Conditioner (A/C) is a strong indication that an air-conditioner does not have enough refrigerant. When the charge on an A/C is low, there is less refrigerant that enters the evaporator. When there is a lower amount of refrigerant entering the evaporator, it takes less ...