harry a crit :
No no no ! It's NOT the same thing AT ALL; one is an efficient electric
heater (heat pumps), the other is a boost on a ventilation system; the
amount of electricity and the temperature increase / decrease aren't on
the same scale at all.
And you're not really correct about the maintenance costs; a heat pump
needs regular maintenance otherwise it's performance suffers, and there
are significant risks regarding the loss of fluids which are significant =
greenhouse gases (just like in fridges). A yearly maintenance contract
for a ground heat pump system costs pretty much the same as the
obligatory yearly maintenance contract for gas, propane or diesel
boilers, and will soon be obligatory here too.
Buried earth pipes pre heat or pre cool air, but should not be relied on =
to provide all heating needs in anything other than a very low
consumption house (passive haus standard or not much more than
10kWh/m2/year), otherwise the heating needs won't be met. Heat pumps, on =
the other hand, can supply all heating requirements if they are properly =
sized and spaced (need to make sure the ground loop wont freeze the sourc=
Pre-heating and pre-cooling is a very interesting goal (environmentally) =
so long as the ventilation electricity use remains minimal. Heat pumps
are less interesting, as they contribute to winter peak electricity
demand, requiring over-sized distribution networks and production units
capable of meeting peak demand (generally old coal / diesel or gas units =
that haven't quite gone into retirement, that are extremely polluting).
Unless they have a season performance ration of over 3, they are less
energy efficient than a high performance gas boiler.