There are many advantages to Air Source Electric Heat Pumps, not the least of which is price; these tend to be the cheaper heat pumps to purchase and install. The biggest drawback of electric air source heat pumps is their inability to function in all weather conditions. Temperatures below -9oC and high wind conditions can affect these units. Backup heating systems are recommended if you live in an area where these conditions exist on a regular basis. The ability of these air source heat pumps to reverse and provide air conditioning as well as heating make them ideal units for the majority.