[Rhodes22-list] alternative energy - houses and heat pumps

[Robert Skinner]

Saroj Gilbert wrote:
> Thanks for so much detail, Robert.. very helpful... I currently live in
> Virginia where the winters are mild... no land for planting at this time,
> but hopefully that will change.

I think land is the ultimate key to energy issues, 
whether they be wind, solar, wood, or grass.  Get 
some.  As Will Rogers said, "They ain't making any 
more of it."
 
> I would like to build an energy-efficient house... preferably a cement dome
> (for a lot of reasons... one of which is that I love the feel of the space
> in a dome... I prefer round dwellings although I haven't yet been fortunate
> enuf to live in one.  They go up quickly, are very strong, very spacious,
> very well insulated (in fact you really need a heat exchanger [RWS - I
> assume you mean an isothermal air exchanger] to ensure
> sufficient fresh air... not enuf leaky windows), and "feel" organic to me...

Geometrically, the volume-to-surface area ratio of 
a dome house offers an optimum shape for heat 
preservation.  As concrete is good in compression, 
and not so good in tension, you would need some 
circumferential bands to help support a concrete 
roof dome.  Internal beams, covered with insulated 
panels (Buckminster Fuller design?) then sprayed 
with gunite would make a rather nice and open 
structure.  As with Bucky's designs, a central 
column could carry utilities.

> preferred heating would be water or ?? through pipes under the floor mostly
> warmed via solar water heater supplemented by a multi-fuel boiler all tied
> together with the hot water system.  Electricity is so inexpensive here that
> it is hard to justify PV but that will change as fuel gets more expensive...
> Electricity is generated from coal and nuclear in this area, but no
> matter... all fuel costs will be affected by the price of oil.  For sure a
> new house would NOT have the usual incandescent lightbulbs.

As another list member has suggested, an heat 
pump working off an underground heat sink such 
as several wells or a long, long buried pipe, 
is an economic way to heat and cool a the 
inside of a structure.

> It is hot and humid here in the summer... I haven't given too much thought
> about the cooling aspect although a water or air using the coolness of the
> earth would be my preference... just not sure how feasible this would be.
> Maybe I should just be out on the boat when its hot... fending off the
> gnats.  It is possible to partially earth-berm domes... that's another
> alternative.

Follow that thought.  As the frost doesn't go 
down more than 5 feet here in southern Maine, 
I'd say that 5 feet of earth would make good 
insulation in VA.  In the '70s, I looked into 
building a house that was mostly underground, 
with grass growing on the roof and an atrium 
that could be covered to let in light and 
variable air, as the season dictated.

I also note that many southern mansions (such 
as Jefferson's Monticello) used cellars to 
cool air that was drawn up through the house 
by thermal chimneys.  That is another way to 
keep a house cool.

Even if you decide to build a dome, I would 
not neglect a good dry cellar, preferably 
with a poured concrete strong room somewhere 
in it -- either as a storm shelter or storage 
for valuables when you travel.  A cellar would 
also be a place for a eutectic salt container 
for thermal storage if you decide to use solar 
energy as a heat source.

Ultimately, you will need to trade off initial 
cost against predicted long term benefits, 
throwing in a healthy dose of maintenance 
overhead as you design an optimal house.  There 
is a lot of good knowledge out there, and also 
a lot of dreaming...

Good luck in differentiating and integrating,
/Robert Skinner