Ground source heating or similar?
Discussion
fatboy b said:
There was a guy on here recently who said that 95% of retrofit situations are a waste of time. The temp the water comes up at is about 25'C - so not hot enough for rads. You need underfloor heating to make it useful.
55 degrees, but yes, it's practically pointless unless you can fit UFH, masssively oversized rads, or LT Rads.Just come back from a taster course on heat pumps today and was on a solar course a few weeks back.
Underfloor heating is the real way to go as it's pointless using radiators. You just don't get the temperatures efficiently.
They also say that the effectiveness depends on the house. Ideally you want a solid stone/ brick built structure where the walls can retain and store the heat put into the house. A wooden frame building wouldn't effectively store the heat in it's structure.
The uber insulation then needs to ideally be on the outside of the house to allow this to work.
Ground source is a big project. 1.3 meter - 1.5 meter deep trenches dug through out your garden. Depending on size of pipe laid and the KW's needed dictates the amount of land dug up. In an ideal world you'd have a paddock/ field that you can churn up.
Another option is to drill a bore hole. How many needed can to a degree be worked out on plotted maps, but these aren't all that detailed currently. So the only real sure way to find out how many bore holes to suit your requirements is to drill one, and see what it gives you. If not enough, drill another. We were told these come at a rough cost of £7K per hole and you might be going down ~70 meters.
Rocky substrate is best to drill into for heat.
You can also lay pipes in water, but you can freeze the water and have an ice skating rink for a few months a year. To get around this problem, flowing water is best.
Air to Air is another option, but you really need to have a unit for each room, so not great for heating a whole house, unless it's open plan or very small.
Air source to underfloor heating works out a lot cheaper than ground source, but it's not as effective. This is partly due to the fact that the air temperature changes daily and you have quite a high range to deal with. They work lovely in the summer when you don't want the heating and crap (not as well) in the winter when you do want the heating. They do work down to -15 degrees, just not to their quoted sales effectiveness.
Ground source on the other hand has a quite predictable temperature throughout the year 1.5 meters down.
They tend to boost the temperature's with an electric immersion type heater. This could also be a small boiler if you liked. The gas/ oil bill disappears, but the electric bill comes and thumps you in the face. Maybe solar PV's to help reduce this, but they cost a bit to put up too!
There is more to them, but I think unless you're designing a brand new build to work with renewable energies, or have quite a bit of money that you fancy spending on being green. I'd tend to stay away from them as yet. The money spent putting them in can buy a lot of gas!
Although, solar thermal panels/ air source heat pumps all work quite well with a swimming pool setup.
Underfloor heating is the real way to go as it's pointless using radiators. You just don't get the temperatures efficiently.
They also say that the effectiveness depends on the house. Ideally you want a solid stone/ brick built structure where the walls can retain and store the heat put into the house. A wooden frame building wouldn't effectively store the heat in it's structure.
The uber insulation then needs to ideally be on the outside of the house to allow this to work.
Ground source is a big project. 1.3 meter - 1.5 meter deep trenches dug through out your garden. Depending on size of pipe laid and the KW's needed dictates the amount of land dug up. In an ideal world you'd have a paddock/ field that you can churn up.
Another option is to drill a bore hole. How many needed can to a degree be worked out on plotted maps, but these aren't all that detailed currently. So the only real sure way to find out how many bore holes to suit your requirements is to drill one, and see what it gives you. If not enough, drill another. We were told these come at a rough cost of £7K per hole and you might be going down ~70 meters.
Rocky substrate is best to drill into for heat.
You can also lay pipes in water, but you can freeze the water and have an ice skating rink for a few months a year. To get around this problem, flowing water is best.
Air to Air is another option, but you really need to have a unit for each room, so not great for heating a whole house, unless it's open plan or very small.
Air source to underfloor heating works out a lot cheaper than ground source, but it's not as effective. This is partly due to the fact that the air temperature changes daily and you have quite a high range to deal with. They work lovely in the summer when you don't want the heating and crap (not as well) in the winter when you do want the heating. They do work down to -15 degrees, just not to their quoted sales effectiveness.
Ground source on the other hand has a quite predictable temperature throughout the year 1.5 meters down.
They tend to boost the temperature's with an electric immersion type heater. This could also be a small boiler if you liked. The gas/ oil bill disappears, but the electric bill comes and thumps you in the face. Maybe solar PV's to help reduce this, but they cost a bit to put up too!
There is more to them, but I think unless you're designing a brand new build to work with renewable energies, or have quite a bit of money that you fancy spending on being green. I'd tend to stay away from them as yet. The money spent putting them in can buy a lot of gas!
Although, solar thermal panels/ air source heat pumps all work quite well with a swimming pool setup.
Excellent post by GBman.
Just to add (as I supply and fit underfloor heating systems with air sourced heat pumps in New Zealand) that you can improve matters by fitting the pipes into a thick concrete slab (100mm is ideal). This becomes the energy store and an air sourced unit could be run in the day when it's more efficient.
Radiators can work, conventionally go for twice the usual size - and never take water up to high temperatures with a heat pump to cool it back down again - big loss in efficiency.
So, any new build fit pipes in the slab.
Just to add (as I supply and fit underfloor heating systems with air sourced heat pumps in New Zealand) that you can improve matters by fitting the pipes into a thick concrete slab (100mm is ideal). This becomes the energy store and an air sourced unit could be run in the day when it's more efficient.
Radiators can work, conventionally go for twice the usual size - and never take water up to high temperatures with a heat pump to cool it back down again - big loss in efficiency.
So, any new build fit pipes in the slab.
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff