Looking for advice on earth tubes. (pipes that run underground to collect/dump heat from outside air as it is drawn into the house)
We have a whole house MHRV system i installed during the renovation pf our house, it,s currently hanging on the wall outside our house with a shelter to protect it from the elements.
It will be relocated into a utility room as once constructed, started on the foundations this week. The plan all along has been to connect the inlet to a series of earth tubes to pre heat the incoming air in winter and provide some free cooling in summer.
Now construction is under way it has dawned on me how many services need to run through the foundations from this one small room, mains water, bore hole water, incoming electric, ground source heat pump loops, sewage, rain water drains, and all services to workshop(water electric, network cables etc)
The other thing i,ve just found out is the cost of Rehau's special pipe for earth tubes, over £2000 for 40 meters
I could use 160mm drainage pipe but 2 runs of that is still £600 and would take an even bigger lump put of the foundations. Also as it's not silver lined it could harbour bacteria as Britain has a wet climate.
Soo, after a bit more research i found a German company producing a system where brine loop/loops collect heat/cool from the ground and condition the air through a big radiator before it enters the MHRV.
http://www.sole-ewt.de/sytembeschreibung/?lang=en
This seems too good to be true, a small loop or water pipe, a pump and a couple of car radiators in a housing.
Any thoughts?