Superheat Calculator

Calculate superheat for air conditioning systems to ensure optimal performance and prevent compressor damage.

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Superheat Calculator

Read from the low-side gauge on your manifold

Measure at the suction line near the service valve

What is Superheat?

Superheat is the difference between the actual temperature of refrigerant vapor and its saturation temperature at a given pressure. It ensures that only vapor (not liquid) enters the compressor, protecting it from damage.

How to Measure Superheat

  1. Connect your manifold gauges to the service ports
  2. Read the suction pressure from the low-side gauge (PSIG)
  3. Attach a temperature probe to the suction line near the service valve
  4. Record the suction line temperature
  5. Use this calculator to determine superheat and system status

Superheat Guidelines

Below 5°FToo low — risk of liquid flooding the compressor
5–10°FLow — monitor system closely
10–20°FOptimal range for most systems
20–30°FHigh — may indicate low refrigerant charge
Above 30°FToo high — system likely needs refrigerant

Refrigerant Types

R-410A

Common refrigerant in modern mini-split and residential AC systems. Being phased out due to environmental concerns.

R-32

Newer, more environmentally friendly refrigerant with lower global warming potential. Increasingly common in mini-splits.

R-454B

Next-generation refrigerant designed to replace R-410A with significantly lower environmental impact.

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Our goal is to provide the HVAC community with helpful resources. If you have ideas for new calculators, improvements to this tool, or technical suggestions, we'd love to hear them.