[Greenbuilding] All Electric House
dantonioli at earthlink.net
Tue Jan 8 15:27:30 CST 2008
I have a customer who is building two new homes in the Oakland hills.
She wants both to be all-electric and wants to incorporate solar,
both thermal and photovoltaics.
Both homes are about to have the roofs put on. The location is far
away from the gas main and she's decided that it's too expensive run
and has told the builder to fill in all the trenches that would have
carried the gas pipes. I told her that before she makes any decisions
that she need to have the final energy performance calculated to see
if they'll pass Title 24 minimum standards (California's energy
code). She's made some very abrupt decisions and there's a good
chance that she'll have to have the trench re-dug and the gas line
Nonetheless, I told her and her architect I would be willing to help
as much as the situation permits, but that they should prepare
themselves for some surprises. (Such as increasing the size of the pv
system, or having to run the gas line after all.)
With a 2.5 to 3.0 KW PV system, and a four module thermal system
feeding an electric hot water heater, a lot can be accomplished.
Unfortunately, she's installing central air heating in both homes,
and feeding that system with an all electric heater will most likely
blow the energy draw out the window, even if it's offset with PV.
Does anyone on the list have experience with "energy efficient all
electric forced air systems," or is that an oxymoron?
What about feeding the heater with a solar air handler? The site has
excellent solar gain; in fact, if they designed passive solar homes
they could accomplish an incredible, passive heating system, but
neither she or the architect thought of it.
Regardless of what she should have done, she's stuck with what she
has. And unless we can come up with a truly energy efficient strategy
for an all electric house then she's very likely going to have to run
the gas line. (Which, by our current energy standards, is bogus given
the fact that natural gas is non-renewable, polluting, and
contributes to global warming. It's hardly "energy efficient" in the
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