Question from Rod Bridges, via e-mail:
When calculating heat demands for rooms, the default air temperature for a hall is 18ºC. This is the room where we normally site the thermostat with no TRV fitted to the radiator. Should the room thermostat be set to 18ºC or 21ºC?
Answer from Martyn Bridges, director of marketing and technical support at Worcester, Bosch Group:
With all things being equal, if the hall temperature is at 18ºC then the room should be at 21ºC (or 22ºC in a bathroom). However, in practice, this isn’t always the case and the rooms in a house can be affected by secondary heating, solar gain and heat produced from cooking etc. They could also be affected by heat loss because of perhaps doors or windows being left open or open chimney’s etc. Therefore, I would suggest an element of trial and error. I would try it at its design setting, say 18ºC and move upwards or downwards by 0.5ºC increments until you feel the house is at a comfortable level.