Inside treatment of passive solar retrofit
precaud
goes to Nick P and Gary R whose generosity with their prior work has
help me immensely.
Overview:
Place: Santa Fe, NM (lots of sun!)
Subject: 1930-built single story home with full daylight basement
under, massive (16" thick) uninsulated masonry walls (two layers of
'pentile', a hollow clay brick, stucco outside, plaster inside.)
Equally massive interior construction.
Project: Tear out south-facing masonry porch and convert to sunspace.
Orientation: Front of house faces 16º east of true south. Porch and SW
bedroom stepped back 5 feet each (dumb design.)
Pics before work started:
http://www.users.qwest.net/~jbau/before.jpg
http://www.users.qwest.net/~jbau/before1.jpg
The porch was an eyesore, and kept much of the south-facing front in
shade. Rather than enclose it, I decided to tear it out and install
polycarb across the corners. This will also allow me to do the same in
the SW corner if this project works out.
Pics with polycarb in:
http://www.users.qwest.net/~jbau/after.jpg
http://www.users.qwest.net/~jbau/after1.jpg
Working with non-right angles made this project a real PITA. What I
thought would take a couple weekends turned into two months. I suspect
most retrofits like this are full of compromise and tradeoffs.
So, the front windows face 16º E of S, and the polycarb (8' wide x 9'
tall) faces 15º W of S. Not perfect but not bad.
In the beginning, the thought was to just to paint the walls black and
open the front door when the sun is shining and close it when it's
not, essentially the "mass behind glass" concept. But since then I've
read about the advantages of low-mass sunspaces and am wondering if I
can apply that concept.
So, the questions are: how best to finish the interior of the
sunspace, and then get the heat into the house.
Sunspace dimensions:
north wall is 78" with 36" x 80" door
east wall is 60"
polycarb is 8' wide, 9' high
How would you deal with this? Is the door going to be sufficient
venting? Any input is welcomed.
amdx
>"precaud" <jb...@qwest.net> wrote in message
>news:e23ed0ee-f3c0-47ad...@f77g2000hsf.googlegroups.com...
>I just discovered this group, what a great resource. A special thanks
>goes to Nick P and Gary R whose generosity with their prior work has
>help me immensely.
Yes, it is a great resource, I just wish it was a busier group.
>So, the questions are: how best to finish the interior of the
>sunspace, and then get the heat into the house.
>Sunspace dimensions:
>north wall is 78" with 36" x 80" door
>east wall is 60"
>polycarb is 8' wide, 9' high
>How would you deal with this? Is the door going to be sufficient
>venting? Any input is welcomed.
Sorry there is not more input to your question, I'll give you my 2 cents.
Paint the walls black, paint the floor white to see if you can reflect some
of the light into the house.
Monitor the temperature near the ceiling in the porch, if it gets hot 85* to
90* then add a fan to
move the heat into the living space. You might use ducting to remove the
heat near the ceiling and
distribute it near the floor in the living area. If you use a fan put it on
a thermostat. Shut the door
at night or when it's cool.
Mike
precaud
> Yes, it is a great resource, I just wish it was a busier group.
Thanks for your reply, Mike. 'Tis a bit slow here, for sure. After not
getting a reply, I decided to experiment. Both the geometry of this
space (a right triangle) and using the door for intake and exhaust are
what raised doubts about applying classic thermosiphon techniques to
it. I decided to try it anyway.
With no inside treatment, useable heat was created by 10am and the max
temps measured 92-94F at the top of the door.
I then insulated the ceiling and stapled up sheeting to taper the
ceiling down from the top of the polycarb to the top of the door. And
hung an 8x8' black aluminum screen 6" back from the glazing. Useable
heat by 9:30am and temps raised to 98-100F.
So I've decided to put up a second layer of screen, and insulate the
interior sunspace walls with R13 fiberglass. (Was going to use
styrofoam board but I don't like the smell of that stuff when it gets
warm.) Noone in town sells foil-faced batts so kraft-faced is my only
choice. Maybe I'll cover them with black polyethylene sheeting. Will
report in when i get those up.
Gordon
@f77g2000hsf.googlegroups.com:
> So, the questions are: how best to finish the interior of the
> sunspace, and then get the heat into the house.
The door may be sufficient. I would put a thermometer in the space and
monitor the temp for a few days. I would expect that you should get
some gain.
One thing that might work, and a low tech solution it is, would to
just use a small fan placed close to the floor to blow air from the
house into the collector space. That would force the convection
and warm air would circulate back into the house.
BTW: Don't overlook the solar gain from that window in the wall
next to your project. Just letting the sun in that window will
have an impact.
precaud
fiberglass, and it comes up to temperature much more quickly now.
Maximum afternoon temps are still about the same but useful heat
production starts a half hour earlier and lasts a half hour later than
before - definitely worthwhile. I'll be happy when the asphalt smell
burns off the kraft paper. Next step is doubling up on the black
screen.
> One thing that might work, and a low tech solution it is, would to
> just use a small fan placed close to the floor to blow air from the
> house into the collector space. That would force the convection
> and warm air would circulate back into the house.
Good idea, and that's exactly what I've been doing. I have the bottom
of the screen pulled out at the bottom so so more air gets pulled up
through the screen, and the fan forces the convection exactly as you
say.
> BTW: Don't overlook the solar gain from that window in the wall
> next to your project. Just letting the sun in that window will
> have an impact.
It's not overlooked - I've been enjoying it for many years!