Hi chaps.

I have been asked to provide hot water and underfloor heating by means of a heat pump and intend to use Daikin Altherma. The building is an office block with 3 toilet and shower areas. One in the middle of the building and one at either end. I am looking to site a hydro box and a hot water cylinder in the middle of the building and then pump hot water in either direction to the other 2 areas. My client has spoken to their plumber who is concerned about heat loss in the pipe work as the total pipe runs will be approx 40 meters in either direction. I had hoped that if the pipe work was properly insulated this would not be an issue. Now the question has been asked I really need some maths to back it up! Can anybody help me with how I would go about calculating the potential heat loss from the pipe run?