David Hansen wrote:
On 15 Mar 2006 15:20:20 -0800 someone who may be
wrote this:-
If the house concerned has more than one room then the hot air has
to be moved between the rooms somehow.
Now theres what I call a challenge.
I don't call it a challenge. However, doing this involves ductwork,
fans (probably) and control systems. What that means is that it is
not as simple as cutting a hole in the side of the house and what
that also means is that there are some costs and energy inputs to
consider.
Sorry, but this is nonsense.
1. Most houses do not have only one room with a south facing wall, it
is more normal to have 2 or 3 on one floor, and 2 on the other. That
makes 4-5 rooms heated directly, or about half of the house typically.
2. Even if no circulation at all were used, a solar panel could still
contribute over half the heating use.
3. Over half because there will be air mixing regardless of what you
do. Add the fact that any houses are open plan, in many the internal
doors get left open, and in many cases part of the south facing wall
supplies a corridor, and you're well over half. Patyback is of course
still good with less than 100% heating replacement.
4. Then add use of the comfort zone, the fact that the solar heater can
take those rooms up to 23 and still be comfortable. This temp diff will
cause heat movement from warm to cooler rooms.
Etc. The assertion that ducts are needed is a flying pig.
NT