Air source or ground source heat pumps: what's best in a harsh climate?
Housing developers, from single-family dwellings to multi-family units and condos understand that consumers are looking for ways to be greener, as well as to get a handle on runaway utility costs. One way is to use heating and cooling systems that use less or no fossil fuels, are more efficient, and operationally have a lower cost.
That includes geothermal (or geoexchange) systems that use ground source or air source heat pumps for heating and cooling. Across Canada, developers are seeing this option as critical on a number of levels. Both types of systems can enhance the housing project, but developers should be aware of and take into consideration the difference in efficiency for each type of geoexchange system based on the local climate.
What developers should know about the difference between geoexchange heating and cooling systems?
First, to understand why location makes a difference, it is important to understand the basics of geoexchange heating and cooling systems. Known commonly as heat pumps, they can be Air Source Heat Pumps (ASHPs) or Ground Source Heat Pumps (GSHPs). In essence, both are exchanging hot or cool air. With an ASHP, the exchange is with the air outside the building. With a GSHP, the exchange is underground through buried piping.
Climate matters when choosing a geothermal exchange heat pump system for your project
While both versions of geoexchange can work anywhere in Canada, the harsher weather in some areas make one type a better option. Since an ASHP is using ambient outdoor air temperatures to harvest heat, the colder it is outside, the less efficient the heating process will be. It will take more electricity to bring the indoor temperature up to acceptable levels, thus reducing the electricity savings that are inherent in a heat pump system. A GSHP system, drawing from the more constant and moderate temperatures underground is able to heat and cool more efficiently. The ability to store heat for the winter underground reduces the impact of the local climate conditions on the efficiency of the system.
Beware, buyers may balk at the extra costs of heating in the harsh winters
As developers work to provide added value to their projects, through sustainable buildings and systems, there can be a misstep if developers choose a system based on relative cost or ease of installation rather than what makes sense for the climate in the area they are building. A developer who installs an ASHP system in an area that would be better suited for GSHP may save a little money, but in the final analysis, the property or properties will be less valuable and less desirable to buyers.
Tell the full story of energy efficiency and a smaller carbon footprint
Housing developers want to tell a new story, one of energy efficiency, sustainable construction and a smaller carbon footprint. It’s a good story to tell, but it can be a better story, with a happier ending if decisions such as what type of geoexchange system to use are made with local conditions in mind. Choose an air source to save installation costs and end up costing the buyer more during the extreme cold of the Alberta winters. In this scenario heat pumps struggle to function and heating is generated from electricity making air source heat pumps the more inefficient and expensive source of heating and cooling. Only ground source heat pumps will remain efficient and level out the heating and cooling costs because it is not affected by the climate and extreme temperatures.
Investigating geothermal for your projects. Spring is the best season to start a new geothermal project and we say, “get your loops in now!” We can help you apply for incentive programs too. Envirotech Geothermal proudly serves the Lakeland, Calgary and Edmonton, Alberta regions including Canmore and Rockyview helping homeowners and builders to discover the benefits and features of geothermal heating and cooling. Contact us today to learn how you can save up to 70% on your heating cooling bills by utilizing geothermal heating and cooling in your home. Call us at 780.220.0842 or request a Geothermal Consultation for more information.