Posted by News on June 12, 2008, 12:36 am
But will it work? If so, it is a cheap way of improving the efficiency of a
such a heat pump system.
Posted by daestrom on June 6, 2008, 11:02 pm
No, from what I can see the hole is *in* the bedrock. It looks like the
walls of the hole are rock face. So he's embedding the concrete and coils
*into* rock, not just on top.
Again, only if you have a similar soil situation. Around my area, you can't
find bedrock that close to the surface. You would need to dig quite a way
down to find substantial rock formation. That changes the economics.
Posted by News on June 6, 2008, 4:51 pm
I would have the plastic the pipe in a figure of 8, so it crosses right
through the concrete block. As it is, it is wound around the outside of the
Posted by daestrom on June 6, 2008, 11:04 pm
If you're going to collect heat with conduction, wound around the outside is
the way to go. If you're going to use it for intermittent storage, then the
figure 8 idea would be better. Guess it all depends which way you think it
will work the best.
Posted by nicksanspam on June 7, 2008, 6:24 pm
Coke in PET bottles has a 6-week shelf-life in a store, determined by loss
of CO2 pressure. Googling, I couldn't find a water vapor transmission rate
for PET bottles (in say lb/ft^2-h per "Hg of vapor pressure difference per
mil of wall thickness), nor their wall thickness. OTOH,
says 100 square inches of "low-density polyethylene" loses about 0.4 grams of
water per day per mil (0.001") of thickness at 40 C (104 F), with 0% RH on
one side and 35% on the other. A graph shows how this decreases linearly with
inverse (1000/T(K)) temperature...