Question from Joseph Viner, via e-mail:
What is the best method of installing an air source heat pump into a system to heat the underfloor heating (UFH)? The current system is split into two zones – an extension using UFH and the rest of the house using radiators. Currently, the whole system is heated via a heat only boiler. I’ll also be using the heat pump to pre heat hot water via a twin coil vented cylinder.
Answer from Martyn Bridges, director of marketing and technical support at Worcester, Bosch Group:
This is a difficult question to answer without seeing the present system layout, but presumably there is a multi zone arrangement in place, which makes two circuits and three zones – two zones for the heating circuit separating the radiators from the underfloor heating and one circuit for the hot water cylinder? If this is the case then it is likely you have a reasonable control system already in place to which the heat pump could literally sit in the position of the boiler connecting to this pre-supposed control system.
Before you undertake this project a number of questions need to be answered:
• Are the radiators sufficiently sized to heat the rooms to the required temperatures when operating at typical heat pump temperatures of between 40-50ºC?
• Is the house insulation effective to the current required Building Regulations? Poorly or insufficiently insulated houses are not compatible with the correct operation of a heat pump.
In summary, I would recommend a site survey is undertaken of the schematic drawings of the current system and sent into the manufacturer of the heat pump to recommend the most suitable layout.