A standard electric heat pump is a heating and cooling system that uses refrigerant to move heat between your home and the outdoors. In the United States, rules for new heat pumps include a global warming potential limit of 700 and a primary installation compliance date of January 1, 2025.
Air-source heat pumps, ductless mini-splits and geothermal heat pumps all use a refrigerant circuit for heating and cooling.
Heat Pump Refrigerant at a Glance
| Question | Answer |
|---|---|
| Do heat pumps use refrigerant? | Yes. Most vapor-compression heat pumps do. |
| What does refrigerant do? | It absorbs and releases heat as it moves through the system. |
| Is refrigerant consumed? | No. It circulates through a sealed loop. |
| Does refrigerant need regular replacement? | No. A recharge usually points to a leak or another repair issue. |
| Can any refrigerant be used? | No. The heat pump must use the refrigerant specified by its manufacturer. |
| Do geothermal heat pumps use refrigerant? | Yes. The ground loop may contain water or antifreeze, but the heat pump itself still uses refrigerant. |
How Does Refrigerant Work in a Heat Pump?
A heat pump uses refrigerant to transfer heat instead of creating heat by burning fuel.
In heating mode:
- The refrigerant absorbs heat from outdoor air, even when the air feels cold.
- The compressor raises the refrigerant's pressure and temperature.
- The hot refrigerant releases heat inside the home.
- An expansion device lowers its pressure and temperature.
- The refrigerant returns outdoors and absorbs more heat.
A reversing valve lets many heat pumps switch the direction of this cycle in summer. The system then removes heat from the home and releases it outdoors, providing air conditioning.
Is Refrigerant the Same as Coolant?
No. Refrigerant is the working fluid inside a heat pump's sealed refrigeration circuit. It is different from the water or antifreeze that may circulate through a geothermal ground loop or a hydronic heating system.
A ground-source heat pump, for example, can use water and antifreeze in underground pipes to exchange heat with the ground. The heat pump unit still uses refrigerant to transfer that heat into the home.
Does a Heat Pump Need a Refrigerant Recharge?
No. A heat pump in good working order should not need routine refrigerant refills. Refrigerant is not fuel, so the system does not use it up during normal operation.
A low refrigerant charge can indicate a leak, an installation problem or damage to a component. Adding refrigerant without finding and repairing the leak is usually a temporary fix. The U.S. Department of Energy identifies improper charging and leaks as maintenance problems that can reduce efficiency and shorten equipment life.
Possible signs of a refrigerant problem include:
- Reduced heating or cooling performance
- Longer operating times
- Ice on the outdoor coil or refrigerant lines
- Higher electricity use
- Hissing or bubbling sounds near the equipment
Only a qualified HVAC technician should test, recover or charge refrigerant. In the United States, technicians who handle refrigerants in covered equipment generally need EPA Section 608 certification. Intentional refrigerant venting is prohibited.
What Refrigerants Do Heat Pumps Use?
The refrigerant depends on the heat pump's age, design and manufacturer.
Common examples include:
- R-22: Used in many older heat pumps. New production and import of R-22 have been phased out in the United States, although existing systems may be serviced with recovered or reclaimed refrigerant where permitted.
- R-410A: Used in many older and existing residential systems. It does not damage the ozone layer, but it has a relatively high global warming potential.
- R-32 and R-454B: Lower-global-warming-potential options used in newer equipment, subject to the manufacturer's design and applicable safety requirements.
A heat pump designed for one refrigerant cannot automatically use another. Changing refrigerants may require different compressors, controls, heat exchangers and safety measures. The EPA states that a refrigerant change generally requires equipment redesign rather than a simple swap.
Are New Heat Pumps Affected by Refrigerant Rules?
Yes. In the United States, EPA rules affect the refrigerants allowed in new residential and light-commercial air-conditioning and heat-pump systems.
Equipment manufactured or imported before the main compliance date received a limited transition allowance through January 1, 2026. The rules mainly affect new equipment selection and installation. An existing heat pump that uses R-410A or another older refrigerant does not automatically need to be replaced.
Can a Heat Pump Work Without Refrigerant?
No. A standard electric heat pump cannot heat or cool effectively without the correct refrigerant charge. Refrigerant is part of the heat-transfer cycle, so a system that has lost refrigerant needs professional diagnosis and repair rather than a routine top-up.
What Should You Do if a Heat Pump Loses Refrigerant?
Have a qualified HVAC technician inspect the system. The technician should identify the cause, repair any leak or damaged component, and charge the heat pump with the refrigerant specified by the manufacturer.