Solar Thermal Capture Tubes - Frequently Asked Questions
How
many tubes are necessary for the average home (let's say 2000
square feet, for the purpose of discussion)?
The
Number of tubes needed for heating depends on the heat loss
v heat gain of the structure far more than Square Feet. Factors
like the insulation R-value, the window sizes and type how
tightly sealed or drafty ETC mean far more than size alone.
Lighting and solar gain windows with night insulation can
add a lot of heat gain. That needs to be balanced against
heat loss through the insulation, and due to drafts, windows,
and doors, especially at night.
http://www.ornl.gov/sci/roofs+walls/insulation/ins_03.html
http://www.ornl.gov/sci/roofs+walls/
http://www.eere.energy.gov/buildings/tech/hvac/
http://www.eere.energy.gov/buildings/tech/lighting/
http://www.eere.energy.gov/buildings/tech/windows.html
http://www.eere.energy.gov/buildings/tech/enveloperd.html
Solar can usually be integrated with the
free thermal resource of the deep ground to create an alternative
energy strategy that allows for the development, implementation,
and deployment of true, zero-fuel energy building designs
that require no fossil fuels at all.
The
deep ground resource in VA varies between 55°F and 63°F
so you want to use as much of that free resource as possible
for heating and cooling your buildings. Then, only a small
amount of added solar gain is needed to heat and store enough
hot space heating water (for around the clock heating from
a 8 hour solar day) to add about 20°F to the free ground
resource temperature. To extract all that free heat from the
ground beneath us we use a closed loop U-tube that requires
no pumping power ad that removes no groundwater from any aquifers.
How many tubes would I need for my house?
For
Domestic Hot Water (DHW) typically 10-25 tubes will suffice
depending on how many people use the system and the size of
the storage tank (Many people install a 50-60 gallon solar
pre-heat tank in addition to the existing DHW tank)
It would also depend on use. Is the solar system used just
for hot water for bathing, etc…..? or also to heat the
house (radiator system)?
I'm also unclear about what is involved in the installation,
and exactly where the tubes come in. Is that something I can
do myself, or do I need to hire a plumber?
If you can sweat solder copper pipe and do the work yourself,
you can save the instillation expense.
http://www.easy2diy.com/cm/easy/diy_ht_3d_index.asp?page_id=35749917
http://www.umass.edu/classes/eng351/examples/pipe.htm
http://www.misterfixit.com/nosweat.htm
http://www.doityourself.com/stry/cutjoincopperpipe
http://www.copper.org/applications/plumbing/techref/cth/cth_main.htm
(Copper Tube Handbook) PDF, chapter VI)
Fossil Freedom can provide some plans for do-it-your-selfers.
It is pretty straightforward……
http://www1.eere.energy.gov/solar/solar_heating.html
http://www1.eere.energy.gov/solar/sh_basics_water.html
http://www1.eere.energy.gov /solar/sh_basics_collectors.html
http://www1.eere.energy.gov/solar/sh_basics_collectors.html#evacuatedtube
The
quickest return would be to install solar Domestic Hot water,
because after heat, the hot water and cloths dryer are the
most energy intensive. Hot water is used year round and quickly
saves a lot of money.
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