If you have just moved into a new home or are unsure of what type of heat pump system you have, this guide will help you determine whether you have a heat pump or an HVAC conventional (air conditioning system).

Heat Pump And Conventional HVAC Differences

Unless you look closely, it is very hard to tell the difference between a heat pump and a conventional HVAC system.

They both look identical on the outside, with a few very minor exceptions. But on the inside, they are quite different.

A heat pump is able to provide both warm and cool air inside your home, whereas a conventional HVAC system will only provide cool air.

Here are some additional key differences between heat pumps and conventional HVAC systems:

  • A heat pump uses a reversing valve that helps it change from cooling mode to heating mode (and vice versa). A conventional HVAC system does not have this reversing valve.
  • A heat pump has an evaporator coil and a condenser coil (as well as a compressor). A conventional HVAC system only has an evaporator coil and a compressor.

Related: Heat Pump Advantages and Disadvantages

How Do You Know If You Have A Heat Pump Or A Conventional System?

Read the label

On the back of your heat pump, there should be a small sticker or label that indicates whether it is a heat pump or not.

If the model number on this sticker starts with the letters HP, then you have a heat pump. If it does not, you have a conventional system.

Look for an instruction booklet

If you cannot find a label on the back of your heat pump, another way to determine whether you have a heat pump or not is to look for an instruction booklet.

Heat pumps will always come with an instruction booklet, whereas conventional systems will not.

Look at the thermostat

A heat pump will have two settings – one for “heat” and one for “cool”. A conventional system will have four settings – “off”, “heat”, “cool”, and “auto”.

If your thermostat only has two settings, you most likely have a heat pump. If it has four settings, you have a conventional system.

Unfortunately, a heat pump and an HVAC system have two sets of coils – an evaporator and a condenser.

The heat pump also has a reversing valve. So, if you’re not sure which system you have, the best way to find out is to contact a professional HVAC contractor and have them take a look.

Related: Can A Bad Thermostat Cause Short Cycling? (POSSIBLY?)

Check the service ports on the unit

If there are three service ports on the unit, you have a heat pump. A conventional system will only have two.

The third service port is for the reversing valve, which is unique to heat pumps. This service port is usually located on the top of the unit, near the electrical connections.

Contact your heat pump technician

Lastly, look around the exterior of the unit and see if there is a metal plate attached. If there is, you should be able to find the serial number and model number of the unit.

These will be helpful when you contact your local heat pump contractor to ask about your system.

Tips for contacting a heat pump technician

When you contact a heat pump technician, be sure to have the following information handy:

  • The make and model number of your heat pump (this can usually be found on a metal plate attached to the unit)
  • The serial number of the unit
  • The size of your home (in square footage)
  • The type of system you have (ducted or non-ducted)
  • If you have an instruction booklet or manual for your heat pump, this will also be helpful.

The technician will be able to help you determine whether you have a heat pump or a conventional system based on the information you provide.

Heat pumps Inside

There are several pipes and valves that come into the house from the outdoor unit. The refrigerant lines (the larger, copper tubing) carry the refrigerant back and forth between the indoor and outdoor units.

The smaller, black pipes are the suction and discharge lines. The suction line carries the low-pressure refrigerant vapor from the indoor unit to the outdoor unit. The discharge line carries the high-pressure refrigerant vapor from the outdoor unit to the indoor unit.

The third type of pipe is called the expansion valve. This valve regulates the flow of refrigerant into the evaporator coil.

The fourth type of pipe is called the liquid line. This pipe carries the low-pressure liquid refrigerant from the outdoor unit to the expansion valve.

Heat pumps outside

The outside of a heat pump looks like a big fan. The fan is used to circulate air around the outdoor unit. There will normally be two pipes (the suction and discharge lines) and an electrical service box attached to the outdoor unit.

The compressor is located inside the outdoor unit. The compressor pumps the refrigerant through the system.

The evaporator coil is located inside the house, usually in the basement or utility room. The evaporator coil absorbs heat from the air in your home and transfers it to the refrigerant.

The condenser coil is located inside the outdoor unit. The condenser coil releases heat from the refrigerant and transfers it to the outside air.

In Summary

Other than what I have mentioned above, there aren’t really any other ways to determine whether you have a heat pump or a conventional system.

If you’re unsure, the best thing to do is contact a professional contractor and have them take a look.

I hope this information is helpful!

Good luck!

About the Author

Passionate about helping households transition to sustainable energy with helpful information and resources.

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