re: adding a solar sunroom?
7 jul 1998
>we are toying with the idea of replacing a deteriorating enclosed back
>porch on our old home with a solar type sunroom. we would make this
>larger than the present room, maybe 20' x 20'
if the back of your home faces south, you might make the sunroom longer
in the ew direction, eg 32' long x 12' deep. that would collect more sun.
>we came across four seasons sunrooms that offer mc2 and mc3 glazed glass.
>has anyone heard of this product?
>is it worth the cost which i'm sure will be high?
i'd say probably not, but it's a matter of taste. "sunrooms" cost
$50-150 per square foot. commercial plastic film greenhouses cost
less than $1 per square foot. home-made greenhouses can cost less.
>we heat mainly with a wood stove which would not extend to that room so
>we're not sure the cloudy in skies will warm the addition but like the
>idea of a solar room. any advice?
sure. make the sunroom with $3 bows on 4' centers made from 2 12' 1x3s
bent to an 8' radius with 1x3 spacer blocks and deck screws every 2' to
hold the bows together. sandwich the bow bottoms to a horizontal 1x3 near
the ground, and bolt it through the treads of used tires on 4' centers
filled with soil to make a foundation and planters inside the room. my
local garage pays me $1.25 each to take away tires; my zoning code says
a building is "anything permanently affixed to the ground :-) you might
build a 32' long x 8' radius quarter-cylindrical structure like this with
materials costing $135, ie 50 cents/ft^2, including the floor, or minus
30 cents/ft^2, with a 2' thick x 3' tall interior wall/bench/planter/
composter made out of 168 used tires. paul farber's "tire recycling is
fun" book (available from aee at (800) 777-6609) explains that you can
cut the faces off tires near the treads with a sawzall or sabre saw blade
that's been sharpened on a grindstone to make a narrower cut by removing
the sideways set of its teeth.
use a cedar or poly-wrapped 1x3 cap strip and deck screws to hold a $25
32'x16' piece of 4 year cloudy (and private) greenhouse polyethylene film
to the horizontal 1x3, drape the excess film onto the ground, and cover it
with gravel to make a walkway and air seal. or use a single layer of replex
polycarbonate plastic, which is very clear, like a window, has a 10 year
guarantee, and comes in 50' long x 49" wide x 0.020 thick rolls for
$250 each + $10 ups from rimol greenhouse systems at (603) 425-6563.
or use bayer's new dureflex urethane film, which costs about 35 cents/ft^2;
(412) 777-2000. it's as clear as food wrap, has a 10 year guarantee, and
comes in 15' wide rolls. it might be stretched over $35 24' long curved
greenhouse galvanized steel pipe bows on 4' centers to make a dramatic
2-story lean-to sunspace like mine, with more pipes as ground stakes and
a pressure-treated perimeter board for the foundation, and $1/linear foot
aluminum extrusions to hold the film. attach each pipe to the eave of the
house with 2 vertical steel angle brackets and a horizontal bolt to make
a hinge. venting and roll-up exterior shadecloth can keep the sunspace
cool in the summer and make the glazing last longer.
make the floor astroturf or shredded wood playground mulch over black
plastic film on the ground. paint the house wall behind it dark, or
hang a $50 piece of dark greenhouse shadecloth over the wall.
in skies are cool and cloudy, but an 8' radius lean-to sunroom with 32'
of r1 solar glazing might gain 332k btu of solar heat on an average
6 hour december solar collection day in evansville, and lose about
6h(80f-40f)384ft^2/r1 = 92k btu while keeping itself 80 f inside, and
provide 240k btu/day of excess heat for the house, equivalent to about
2 cubic feet of wood or 2 gallons of oil per day.
nrel's 30-year december weather averages for indiana:
24 hour daily average sun on standard avg sun on
air temp max temp horiz. surface deviation south wall
evansville 35.2 f 43.6 570 btu/ft^2-d 52 870
fort wayne 28.6 35.5 450 41 650
indianapolis 30.9 38.5 510 54 770
south bend 28.9 35.4 430 36 580
nicholson l. pine system design and consulting
pine associates, ltd. (610) 489-0545
821 collegeville road fax: (610) 489-7057
collegeville, pa 19426 email: email@example.com
computer simulation and modeling. high performance, low cost, solar heating and
cogeneration system design. bsee, msee. senior member, ieee. registered us
patent agent. hi/dvc board member. web site: http://www.ece.vill.edu/~nick