When are Heat Pumps Appropriate?
Heat pumps can provide effective, controllable and reasonably effective heating providing certain criteria are met.
- The efficiency of a heat pump depends on the temperature difference between where the heat is sourced and the final water or air temperature. As underfloor heating runs at a lower temperature than radiators they will give a better efficiency, alternatively larger radiators are recommended.
- Heat pumps are good at delivering a fairly constant heat, they do not react as quickly as a normal boiler system and will be inefficient if rushed. They are therefore best suited to properties which are occupied for most of the day, ie they not well suited to those who are hardly ever at home.
- Heat pumps with radiators work well in combination with wood stoves where the heat pump provides a background heat but the wood stoves are used to achieve higher temperatures in individual rooms and give faster response if the house has gone cold. If there is underfloor heating a wood stove is less useful.
- Air source heat pumps are more efficient in mild to cold weather so can be used in spring and autumn on their own, but if a wood stove is available the heat pump should be used less as the weather gets very cold, ie the wood stoves then should provide a greater proportion of the heat load.
- With ground source heat pumps it is important to make sure the ground loop is big enough for the heat demand, skimping on this will cost much more in the long run.