Air source vs ground source heat pump – a closer look
There are a plethora of options when it comes to heating and cooling water in your home. Once less discussed option are heat pumps. Heat pumps are a ‘green’ solution to residential heating. These pumps have become very popular because of green incentives and can be a wise investment for many when implemented correctly.
There are a variety of different types of heat pumps in the market today, which can make it a challenge when deciding on the most suitable heat pump for their particular situation. The air source heat pump and ground source heat pump are the two most popular types of heat pumps.
Needless to say, each has its own pros and cons and can be suited towards one particular situation over another. We have taken the step of looking at it closer to help you understand the difference between the two and help you make a decision on which one is the best for you.
As you may notice from the name, ground source heat pumps, also known as earth-energy system (EES), absorbs heat from the ground, while air source heat pumps usually absorbs it from the air.
Heat Pump Pricing
There is a notable difference in cost when it comes to installing the air source heat pump and a ground source option. The main reason why there is a difference in the cost of the two is because the ground source heat pump requires you to bore deep holes in the ground surrounding your home. There is also the option of laying the pump in a horizontal position, but this will require a lot of space. And in today’s neighborhoods, space can come at a premium.
Heat Pump Size
Air source heat pumps look quite similar to a traditional A/C unit and can be the more compact option of the two. Air source heat pump units vary in size depending on need and size of the home. Generally, the normal size is approximately 3’ square but there are differences between the different models available.
Considerations for a Ground Source Heat Pump
The ground source heat pump can be buried in your garden, backyard or some other outdoor space near your home. This of course means you will have to make considerations on whether you have the area to bury the ground source heat pump. It’s also worth mentioning you will need access for heavy machinery.
Heat Pump Efficiency
If installed correctly, the ground source heat pump is typically the more efficient option over the air source alternative. This is because the ground source pumps finds it easier to heat the water throughout the year. All of this is owning to the fact the temperature of the ground doesn’t change significantly.
During the summer, the air source heat pump will work fine because the air is warmer. During the winter, the temperatures are lower which translates to the pump working harder to provide the hot water for the temperature required. All in all the ground source option, though harder to install, is the more ‘green’ option.
Heat Pump Performance
The performance of the heat pump is measured using Coefficient of Performance. This is the ratio between the heat delivered from the pump and the amount of energy needed to power the compressor. When you see a heat pump with a CoP of 2.3 then that means that there is 2.3kWh of heat for every 1kWh that has been used to power the pump compressor.
“Air source heat pumps usually have a wider range compared to a ground source pump”, according to Brian Connell of Ground Sun a ground source heat pump installer. “They usually average a CoP of 2.5 throughout the year, though the CoP can greatly vary. On the other hand, ground heat pumps will average a CoP of 4, it is the efficient option with less room for variation, he says.“