number of heat pumps vs coefficient of performance from Energy Saving Trust
Sami recently wrote 80% of UK Heat Pumps Performing Badly and suggested that "Lloyd will no doubt be feeling more than a little validated by this study." Indeed; I will never understand why people will shell out tens of thousands of dollars on heat pumps, new windows and solar panels before they will insulate or caulk. But the study makes some good recommendations about how to get the most bang for your buck when you buy a heat pump and how to ensure that it is done right.
Heat pump diagram from Energy Saving Trust
These are from the United Kingdom, so few people have forced air systems as radiators are common. But most of the recommendations from the Energy Saving Trust apply to North American circumstances.
When you should consider a heat pump
In a well-insulated existing property off the gas network. Heat pumps have the potential to reduce running costs compared with oil, direct electric, LPG [propane], or coal, and can provide substantial carbon savings over the lifetime of the installation.
In new-build properties.
How to get the best performance from a heat pump
- Ensure your dwelling is insulated as much as possible (e.g. cavity and loft insulation) prior to a heat pump being installed.
- Install the heat pump with low temperature under-floor heating or properly sized radiators.
- Insist upon understandable, user-friendly controls.
What to expect from a heat pump installer
- Ask the installer to explain how s/he has determined the appropriate type and size of heat pump for your property. The installer should explain how s/he calculated the heat demand of your property.
- Make sure the installer explains how the heat pump will work with your existing heating system (including radiators and hot water supply).
- Ask for guidance to operate the heat pump system controls.
- Ask how often you should run the heat pump.
More at The Energy Saving Trust
Much of my enthusiasm for natural gas is waning with the continuing expansion of Fracing and the environmental damage that is being caused by it. But I am still not convinced that ground source heat pumps are a cost effective solution, especially as air-to-air heat pumps approach their coefficient of performance for a lot less money.