Can you use air con in reverse to heat in the winter? ASHPs can cool right? Can you heat my retail outlet with a heat pump? All questions I’ve been asked that illustrate the confusion out there about heat pumps and cooling.
Here’s my attempt to clarify a little.We name things a bit confusingly in the UK. Both “air con” units and “ASHP “ are heat pumps. Both can give out both heat and cool. The key difference is in how we get that warmth or cooling into our living spaces and the degree of cool that they are able to provide.
Take ASHP first: they are designed to heat water, hence also called air-to-water heat pumps. Currently the BUS grant is only available for this type of heat pump. The water they heat or cool can be piped around your house into radiators for heat; your hot water cylinder for hot water; your UFH or fan-coil units for cooling; linked to your MVHR for heating or cooling the air they blow around.
Two main drawbacks when it comes to cooling - you have to be really careful about condensation with pipes of cool water; chilled water isn’t that effective at cooling at the temperatures an ASHP can get it to.
Air con next: these are designed to heat or cool air, hence also called air-to-air heat pumps. They are cheaper than ASHP. They heat or cool air by piping heated and cooled refrigerant into your home that fans blow air across. These fans can be ducted units in the loft, cassettes in the ceiling, fan-coil units on the wall, bulkhead units like you get over the door in a hotel. They are very effective at both heating and cooling efficiently.
Three main drawbacks - they don’t heat your hot water, some people don’t like being heated with blown air, most houses in the UK have radiator systems that then become redundant and need to be replaced with blown air units of some description.
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