Quick answer
Condensation temperature is the temperature at which refrigerant vapor turns back into liquid inside the condenser, fixed by the high-side (head) pressure, and is also called the saturated condensing temperature.
It must stay above the outdoor air so the condenser can shed heat. For R-32, NIST data put a 110°F condensing temperature at about 375 psig, rising to about 429 psig at 120°F.
Quick facts
The key facts about Condensation Temperature, with sources:
- Also called
- Saturated condensing temperature (SCT), condensing temperature
- Set by
- Liquid or discharge (head) pressure and the refrigerant's curve 1
- R-32 at 375 psig (389.58 psia)
- 110°F 1
- R-32 at 429 psig (444.04 psia)
- 120°F 1
- Used for
- Subcooling = condensing temperature − liquid line temperature 2
- Rises with
- Outdoor heat, dirty condenser coil, overcharge, non-condensable gases
Key takeaways
- Condensation temperature is the refrigerant's condensing point in the outdoor coil during cooling.
- Head pressure sets it; each refrigerant has its own curve 1.
- It must sit above outdoor air, so it climbs on hot days and the compressor works harder.
- A dirty outdoor coil or overcharge pushes it up and cuts efficiency.
- In heat pump heating, the indoor coil is the condenser, so this temperature sets how warm the supply air feels.
What condensation temperature is
In the condenser, hot vapor from the compressor gives up heat to outdoor air and turns back into liquid. Like boiling, condensing happens at a set temperature for a given pressure. That temperature is the condensation temperature.
For heat to flow out, the refrigerant must be hotter than the air blowing across the coil. So on a 95°F afternoon, the condensing temperature might be 110°F or more. The compressor has to raise the pressure high enough to reach that.
It is the high-side partner of the evaporation temperature. The gap between the two is the "lift" the compressor provides, and it drives how much power the system draws.
What sets the condensing temperature
- Outdoor air temperature → the floor the condenser must stay above
- Condenser coil size, cleanliness and fan airflow → how easily heat leaves
- Refrigerant charge → how much liquid stacks up in the coil
- Non-condensable gas (air) in the system → raises pressure without helping
- Balance of all four → head pressure → condensation temperature (from the PT curve)
How it behaves
Condensing temperature tracks outdoor temperature. As the afternoon heats up, head pressure and condensing temperature rise with it. The compressor must push harder, drawing more power and delivering a little less cooling. That is the physics behind EER2, the efficiency rating at 95°F outdoors.
A dirty coil acts like a hotter day. Cottonwood fluff, grass clippings or dryer lint on the fins slow heat transfer, so the system must run hotter to get rid of the same heat.
Overcharge stacks extra liquid in the coil, leaving less surface to condense vapor, which also raises pressure. Air or nitrogen left in the system after a repair, called non-condensables, adds pressure on top.
In a heat pump in heating, the indoor coil is the condenser. Its condensing temperature sets how warm the supply air is, which is why heat pump air often feels cooler than furnace air.
Why air in the lines raises condensing pressure
Air and moisture do not condense at the pressures inside an AC. If they are left in the lines after a repair, they collect in the condenser, take up space and add their own pressure. Head pressure rises without any gain in cooling, and moisture can react with the oil.
That is why installers pull a deep vacuum before charging. The Goodman R-32 manual says to evacuate below 500 microns and hold for at least 10 minutes.
A rise that levels off below 1,000 microns means the system is leak-free; a rise that holds between 1,000 and 2,000 suggests moisture or a small leak and calls for another evacuation; a rise above 2,000 means a leak that must be found and repaired 2.
Sources: [2]
Condensing temperature when a heat pump heats
In heating, the reversing valve sends hot vapor to the indoor coil, which becomes the condenser. House air at 68°F or so flows across it and takes the heat. The condensing temperature must sit well above that air for heat to move, and it sets how warm the air at the registers feels.
As outdoor temperature drops, a heat pump has less heat to move and its indoor condensing temperature tends to fall, so supply air gets cooler. Variable-speed systems may slow the blower to keep supply air warmer. Either way, the air can feel cooler than furnace air even when the house holds its setting.
R-32 condensing temperatures and pressures (NIST)
| Condensing temperature | Pressure (psia) | Approx. gauge (psig) |
|---|---|---|
| 90°F | 296.02 | 281 |
| 95°F | 317.61 | 303 |
| 100°F | 340.37 | 326 |
| 105°F | 364.34 | 350 |
| 110°F | 389.58 | 375 |
| 115°F | 416.13 | 401 |
| 120°F | 444.04 | 429 |
Worked example: a 10°F hotter day
An R-32 system evaporating at 40°F (135.65 psia) 1. Assume the condenser runs 15°F above outdoor air (an illustrative approach; real values depend on the unit).
| Outdoor temperature | Condensing temperature (assumed +15°F) | Head pressure | Pressure ratio vs suction |
|---|---|---|---|
| 95°F | 110°F | 389.58 psia ≈ 375 psig | 389.58 ÷ 135.65 ≈ 2.87 |
| 105°F | 120°F | 444.04 psia ≈ 429 psig | 444.04 ÷ 135.65 ≈ 3.27 |
| Change | +10°F | +54 psi | About 14% more lift |
Ten degrees of outdoor heat raises the pressure the compressor must create by about 14% in this example. A dirty outdoor coil has the same effect as a hotter day, which is why cleaning it is one of the most useful owner tasks.
Where you see condensing temperature
- On a digital gauge, as SCT or saturated liquid next to liquid or discharge pressure.
- In subcooling math: condensing temperature − liquid line temperature 2.
- In maker performance tables, where capacity and power change with outdoor temperature.
- Indirectly in EER2, the rating at 95°F outdoors.
Lower vs higher condensing temperature
Lower (within range)
- Less compressor power per unit of cooling.
- More cooling capacity.
- Less stress on the compressor and its oil.
Higher
- Higher power draw and bills.
- Lower capacity on hot days.
- Higher discharge temperatures; more wear.
- Can trip high-pressure safety controls.
Limits of the number
Condensing temperature alone does not prove charge is right. It must be read with subcooling and outdoor temperature. A high reading on a 105°F day can be normal; the same reading on an 80°F day points to a problem.
Blends need the right data. R-454B has a temperature glide of about 1.5 K, so its condensing begins and ends at slightly different temperatures 3. Chemours also reports that, compared with R-410A in its test cases, R-454B runs 140 to 229 kPa lower discharge pressure and a higher discharge temperature 3.
Sources: [3]
What it means for running cost
Every degree the condenser runs hotter than it needs to costs compressor power. Keeping the outdoor coil clean, the fan working and the charge right holds the condensing temperature down. These are low-cost fixes compared with lost efficiency all summer.
For repairs, see refrigerant leak repair; for running costs, the energy savings calculator.
How a technician uses it
- Note outdoor temperature and confirm the condenser fan and coil are clean.
- Read liquid or discharge pressure (EPA 608 certified work) 4.
- Convert to condensing temperature with the refrigerant's data 1.
- Measure liquid line temperature and calculate subcooling 2.
- Compare with maker data for the outdoor temperature.
- Diagnose: dirty coil, fan, overcharge, non-condensables or restriction.
Owner tasks that keep it down
- Keep plants, fences and debris away from the outdoor unit.
- With power off at the disconnect, gently rinse the outdoor coil from inside out; never pressure-wash the fins.
- Do not stack items on top of the unit; the fan discharges up.
- Do not shade the unit with a structure that traps hot air.
- Book a yearly coil and fan check.
Warning signs of high condensing temperature
- Very hot air from the outdoor fan with weak cooling inside.
- Outdoor unit shuts off and restarts on hot afternoons (high-pressure safety).
- Visibly matted or dirty outdoor coil.
- Outdoor fan not spinning while the compressor hums: turn off at the thermostat and call.
- Refrigerant diagnosis and repair require an EPA 608 certified technician.
Rules that apply
There is no code limit on condensing temperature; it is an operating condition. Reading high-side pressure is service work under EPA rules: technicians must hold Section 608 certification 4, and knowingly venting refrigerant is prohibited 5.
Equipment ratings reflect it indirectly: DOE's EER2 rating is measured at 95°F outdoors, and the Southwest has EER2 floors for split ACs installed there.
Condensation temperature vs related terms
| Term | What it is | Relation |
|---|---|---|
| Condensation temperature | Condensing point in the condenser | High-side saturation |
| Evaporation temperature | Boiling point in the evaporator | Low-side saturation |
| Subcooling | Liquid below condensing point | Condensing temp − line temp |
| Dirty condenser coil | Fouled outdoor coil | Raises condensing temp |
| EER2 | Efficiency at 95°F | Reflects hot-day condensing |
Common misconceptions
- Myth High head pressure means plenty of refrigerant.
- Reality It can mean overcharge, a dirty coil or air in the system.
- Myth Hot air from the outdoor unit means it is broken.
- Reality In cooling, it is supposed to blow hot air.
- Myth Shading the unit always helps.
- Reality Light shade can help a little; boxing it in traps hot air and hurts.
Hot climates and condensing temperature
Places with very hot afternoons, such as Arizona and inland California, push condensing temperatures highest, which is one reason DOE added an EER2 floor at 95°F for split ACs installed in the Southwest. In milder places like Washington, condensing temperatures stay lower and efficiency holds up better through the day.
When this matters to you
Watch for high condensing temperature when your AC struggles on hot afternoons or your bills jump in summer. Clean the outdoor coil first; then ask a tech to check charge and fan operation.
Next step: read how the whole refrigeration cycle works.
Questions about Condensation Temperature
What is condensing temperature?
It is the temperature at which refrigerant vapor turns back into liquid inside the condenser, set by the high-side pressure. For R-32, NIST data put 110°F at about 375 psig.
Why does condensing temperature go up on hot days?
The condenser must be hotter than the outdoor air to shed heat. As outdoor temperature rises, the system raises its head pressure and condensing temperature to keep heat flowing out, and the compressor works harder.
What causes high condensing temperature?
Hot weather, a dirty outdoor coil, a failed or slow condenser fan, overcharge and non-condensable gases such as air left in the system. A technician checks each with readings and inspection.
How does condensing temperature affect efficiency?
The higher it is, the more pressure the compressor must create, so it draws more power for the same cooling. In this page's example, a 10°F hotter day raised the needed pressure ratio by about 14%.
How is condensing temperature measured?
A technician reads the liquid or discharge pressure and converts it to temperature using the refrigerant's data. Digital gauges display it as saturated condensing temperature.
What is condensing temperature in heat pump heating?
In heating, the indoor coil is the condenser. Its condensing temperature sets how warm the air from the vents is. It is lower than furnace heat, which is why heat pump air can feel cooler.
Can I lower my AC's condensing temperature?
Yes, by keeping the outdoor coil clean and clear of debris and plants so air moves freely. Turn the power off at the disconnect before rinsing the coil. Charge and fan repairs need a technician.
Is condensing temperature the same as discharge temperature?
No. Discharge temperature is the hot vapor leaving the compressor, well above the condensing point. The vapor cools to the condensing temperature in the coil before it turns to liquid.
Sources
- NIST Chemistry WebBook, Thermophysical Properties of Fluid Systems: difluoromethane (R-32) saturation properties, 30°F–120°F, retrieved .
- Goodman / ACiQ, A/GPHM3 13.4 SEER2 M-Series packaged heat pump with R-32, installation instructions (IOG-3035B, 2025), retrieved .
- Chemours, Opteon XL41 (R-454B) Product Information (C-11001, 9/2016), retrieved .
- U.S. EPA, Section 608 Technician Certification, retrieved .
- U.S. EPA, Stationary Refrigeration: Prohibition on Venting Refrigerants, retrieved .
Expert review
Written by the HyreHVAC Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: R-32 pressure-temperature pairs copied from the NIST Chemistry WebBook (psig = psia − 14.7); subcooling formula from the Goodman R-32 manual; R-454B glide and pressure comparison from Chemours; EPA rules read 10 October 2026. The +15°F condenser approach in the example is assumed.
Suggest a correction. We fix errors and say what changed.