Re: How to heat a very old house?
Quote:
Originally Posted by
peterb
A couple of friends of mine have air source heat pumps.
We had those in NZ (also known as AirCon in Australia). Ok until it got too cold and would have to have a 'defrost' cycle for 15 minutes oh or go completely when the power went (5 times in 2 years, reminded me of the 70's). Anyhoo...
We also had a fire and electric heaters, waking up in 12 degrees with a numb head isn't great fun in the winter, above all else sort out insulation before heating.
The house we were in, great location, but built like a shed - back in the UK with similar temps and I barely have to have the heating on because our insulation is so good. Yeah it's not as old as the one you're dealing with (very envious btw) but I would try and figure out your insulation first (there must be options even for old buildings) otherwise you'll be throwing cash out the window.
Oh yeah, and insulation. :)
Re: How to heat a very old house?
Quote:
Originally Posted by
Mason.Lyons
I use electric oil radiators and after a while they put out a fair amount of heat. Could try looking into those.
Classic mistake. With plain electric heaters (including these oil filled ones), electricity in = heat out. The oil filled radiators are just quieter than fan heaters.
On the subject of Air source heap pumps, I have air conditioning in my house that operates in a revers cycle. When 700 Watts of electricity goes in, about 2.5 kw of heat (or cold) is transferred. However even though my evaporators are supposedly decent, even at their quietest, during the night I wouldn't call them quiet. They seem silent during the day though.
I believe ground source uses less energy because there is less heat pumping to do. At the depth the pipes are buried (2 ish meters IIRC) the ground is a constant 12 degrees C all year round. During the winter, pumping hear from 12 degrees to 22 degrees will take less energy than from 0 degrees to 22 degrees.
I will also speculate* that during the summer, maybe ground source could be used as air conditioning just using the heat exchanger - no heat pumping.
The area used for ground source is directly proportional to how much it is going to be used - the ground it is under/around heats up/cools so it loses effectiveness if the circuit isn't big enough.
Speculate - as in I haven't a clue if this is the case to me. It just seems logical.
Re: How to heat a very old house?
Quote:
Originally Posted by
badass
.... I believe ground source uses less energy because there is less heat pumping to do. At the depth the pipes are buried (2 ish meters IIRC) the ground is a constant 12 degrees C all year round. During the winter, pumping hear from 12 degrees to 22 degrees will take less energy than from 0 degrees to 22 degrees. ....
Common misconception - you're not heating the ground, or the air, or even heating water from ground/air temperature to room temperature. You're heating a separate transfer loop, using a heat exchanger, which pulls heat from the source, making the source colder. In air source the transfer loop essentially runs through a radiator that is warmed by the air around it (or blown over it); in ground source the transfer loop is literally a lot of hose that runs cold water into the ground where the ambient ground temperature warms it up again (cooling the ground as it goes).
Since rate of heat transfer is proportional to delta-T, as long as the temp difference between the source and the transfer loop is the same both systems would be equally efficient. The temperate within the transfer loop probably doesn't vary that much between exchanger and source (in the same way that the water temperature in a water cooling loop doesn't actually vary that much) because water has a very high specific heat capacity. So for air source the difference will be that the transfer loop runs colder, but it should carry the same energy to the heat exchanger.
Re: How to heat a very old house?
Gotta be option 1.
Stick with safe, cheap (rare to get cheaper then mains gas for heating) and guaranteed heating long term. No headaches with land issues, newish technology, or relying on payment's from the government to ensure it is financial viable.
Then supliment it with quality, properly installed and specced wood burners in sensible locations in the house, following Zak's advice back in the thread.
