Hi, I’m about to start groundwork next week and have hit a brick wall in our decision on heating for bungalow (5 bed - 285 sq/m). We are getting a condensing oil boiler for cost reasons with possibility of switching to another heat source down the line. Just cant justify extra 15k for geothermal (or 10k for wood pellet) at the moment. We are putting our money into additional insulation/airtight membrane and MHRV to hopefully minimise the amount of heat required by the house. My architect recommends we go with a mixed system with underfloor in the living areas and rads in bedrooms. Our plumber however recommends underfloor throughout.
Arguments for mixed system are:
1) We are not heating bedrooms unnecessarily; give them a quick blast in the late evening and morning using timers.
2) Slightly reduced cost of not having to lay underfloor pipes in half the house (offset by cost of mixing valves to get mixed system to work correctly)
3) Architect reckons that the two systems work fine side by side as the return temperature from Rads is perfect for use in the underfloor and that possibly the plumber wants to install the simplest system rather than the best system.
Arguments for full underfloor system are:
1) Simplicity of system. Not complicating things by having 2 systems which work at different temps.
2) If we do switch to geothermal or similar down the line, the underfloor will work better with these.
3) Water doesn’t need to be heated to as a high a temperature leading to presumed lower amount of time the boiler needs to be working.
4) Efficiency of condenser is increased as there is a lower return temperature of the water, therefore the temp difference is greater between water and condenser part of boiler.
We need to decide on this in the next week or so as the floor maekup will be different depending on what we choose. I’ve read countless threads on here and other sites on the subject but cant decide. Have read a few threads which said that underfloor and oil are not a good combination at all and will cost a bomb to run but if we have better than average insulation and minimise drafts (no hole in the wall vents or open fires) would this still be the case? Maybe both systems will work ok? And it doesn’t matter what we pick.
Based on the arguments above, anyone have a tuppence worth to throw into the debate which might swing my mind in either direction?
Arguments for mixed system are:
1) We are not heating bedrooms unnecessarily; give them a quick blast in the late evening and morning using timers.
2) Slightly reduced cost of not having to lay underfloor pipes in half the house (offset by cost of mixing valves to get mixed system to work correctly)
3) Architect reckons that the two systems work fine side by side as the return temperature from Rads is perfect for use in the underfloor and that possibly the plumber wants to install the simplest system rather than the best system.
Arguments for full underfloor system are:
1) Simplicity of system. Not complicating things by having 2 systems which work at different temps.
2) If we do switch to geothermal or similar down the line, the underfloor will work better with these.
3) Water doesn’t need to be heated to as a high a temperature leading to presumed lower amount of time the boiler needs to be working.
4) Efficiency of condenser is increased as there is a lower return temperature of the water, therefore the temp difference is greater between water and condenser part of boiler.
We need to decide on this in the next week or so as the floor maekup will be different depending on what we choose. I’ve read countless threads on here and other sites on the subject but cant decide. Have read a few threads which said that underfloor and oil are not a good combination at all and will cost a bomb to run but if we have better than average insulation and minimise drafts (no hole in the wall vents or open fires) would this still be the case? Maybe both systems will work ok? And it doesn’t matter what we pick.
Based on the arguments above, anyone have a tuppence worth to throw into the debate which might swing my mind in either direction?