I had a heat pump installed, which serves both to cool the air on very hot days (right on high street - opening front windows result in loud street noise, lots of flies and horrendous dust!) and to warm the flat in winter. The heat pump consists of two types of units, a wall or ceiling unit located in each of the rooms and a compressor / evaporator outdoors. There are two types for the outside unit, air and ground based (coils buried in soil). Air-based units will warm or cool a room in a matter of minutes when correctly sized. However, they become extremely inefficient for heating when the outside air temperature drops below about 5 - 8 Celsius. They will typically revert to resistance heating below these temperatures, resulting in huge electric bills! Ground-based units retain their efficiency, since the ground temperature pretty much stays at 10 - 15 degrees year-round. In both cases, note that all internal units must operate in either heating or cooling mode - you cannot have some on heat and some on cool. A great benefit is that you only need to turn on the unit and get to comfortable temperatures in a matter of 5 minutes or so, and you can just turn on units in the rooms you are using. When turned off, they have a frost protection setting which ensures that the room itself never drops below freezing, thus preventing any possible water pipe damage that might be running in or under the floors of the rooms.Given UK climes, air-based heat pumps will not provide the energy savings and economical operation that is required year-round. For those without gardens, it is not a good solution! Note too, the installation cost - air-based will be about 5X the cost of a gas boiler, and ground based will probably run you more like 10X plus. How many people can afford it?
Richard Lo ● 1325d