How Does My Heat Pump Operate? Ground-Source and Air-Source Pumps, Explained

Most people think heat pumps are for heating the home, and while that’s true, they can actually cool your interiors, tool. This makes them more cost-efficient for homeowners. Think they’re too good to be true? Think again. In this post, we’ll take a deep dive into your heat pump’s intricacies and discover how it works.

What are the different types of heat pumps?

There are two common types of heat pumps for residential properties:

• Air-source heat pump. An air-source heat pump (ASHP) is a type of heat pump that pulls heat from the outside air and then transfers it indoors (or vice versa).
• Ground-source heat pump. Also known as a geothermal heat pump, a ground-source heat pump (GSHP) draws heat from under the ground.

Whichever type of heat pump you own, the processes that they employ to heat and cool the home are pretty similar.

How does an air-source heat pump operate to cool the home?

A common misconception is that air-source heat pumps create heat. However, they’re not actually designed to do that—they simply move air around to either cool or heat the home. Here’s how they work to cool the home:

1. The ASHP draws warm indoor air.

2. The air passes over an evaporator coil, which contains a liquid coolant.

3. The coolant absorbs the heat, causing it to turn into gas.

4. The gas is compressed by a compressor, causing its pressure and temperature to rise.

5. The high-pressure gas goes through the condenser coil, where it releases heat to the outdoor air. During this stage, the coolant returns to a liquid state.

6. The coolant returns to the evaporator coil, and the air is circulated indoors.

7. The process repeats.

When it comes to heating, an air-source heat pump will simply draw air from outside (even if it’s cool). This is because cool air can still turn the coolant into a gas, and eventually, into usable heat. The main difference is that, rather than releasing heat outdoors, the heat is released into the indoor air.

How does a ground-source heat pump operate to cool the home?

GSHPs operate in a similar way as ASHPs. Here’s how they cool a home:

1. The GSHP uses a series of pipes that circulate a heat transfer fluid (often a combination of water and antifreeze).

2. This heat transfer fluid absorbs hot air from inside the home.

3. The heat transfer fluid releases the heat underground, where it gets a chance to cool down. Meanwhile, the air inside the home is also cooled.

4. The heat transfer fluid, now cool, returns to the pipes and the process repeats.

To heat the home, the process is similar but reversed. The GSHP pulls warm air from underground (using the same pipes containing coolant) and transfers it into the home. It’s also worth noting that, when heating, the fluid will go through a compressor to increase the absorbed heat’s pressure and temperature.

Need a heat pump for your home?

Depending on your needs, a heat pump may be more suitable for your home than other systems. This is especially true if you live in an area where the outdoor temperature never drops to extremely low levels, or if you’re trying to be more eco-conscious. If so, be sure to contact the top-rated HVAC technicians at Beeson Mechanical Service—our team would be delighted to discuss your options with you. Call 317-535-9338 today to schedule an inspection.