I am renovating my house and would like some advice on floor heating for my living room. I have dug this room out to a depth of 97 cm to create a lower level. I have lined this box with 2.5 cm thick polystyrene and then a double layer steel reinforced concrete floor of 15 cm.
I am now looking to add a hydronic floor heating system to this lowered area. As I understand it I have two basic options.
- add the pipes directly on the concrete with a layer of screed or
- add a layer of insulation in which (or on top of which) the pipes are fastened and then add a layer of screed
I would like to know which system would be the most efficient in my case. Reading up on option 2, it seems like this heats up the room faster, but you are not utilizing the concrete floor as thermal storage, so you lose the heat very fast as soon as the boiler is switched off. With option 1 it takes longer to heat up, but then you are also using the concrete floor as thermal storage.
EDIT: I fear I may have under-insulated by only adding 1 inch of insulation (extruded polystyrene), thereby negating the effectiveness of the thermal store.
Could someone please give me some pointers?