Solar

[NutmegCT]

I'm thinking starting with each corner window skipping every other & ending up with a double collector in the middle...a big sheet of plywood in the window inserts painted flat black.....& that's a good idea about some sort of passive collector behind the remaining windows (though not blocking them) to retain heat.

I've been trying to figure out some way to block heat during the summer - I'd initially thought about building some removeable window coverings out of black screen.

Tony - I'm starting a new thread. Figure folks interested in temps didn't expect to read all this solar stuff.

If you're meaning to use the black painted plywood to heat the air, I'd really suggest you use black painted aluminum sheets - or even black aluminum screening. You need the air to pass along both sides of it, absorbing the heat that the "black" brings in. Unless the plywood is *really* thin, it's actually acting as a kind of insulator.

Plywood won't absorb and release the heat as efficiently as a sheet of metal.

 

[NutmegCT]

Tony - here's the link to the "temperature" thread:

https://www.britishcarforum.com/bcforum/ubbthreads.php/topics/520906/

 

[tony barnhill]

Good deal - until I can figure out how to merge the specific solar-related posts from there to here, folks just need to scroll down to your post that says:

42F today, but heading down for the rest of the week - and sn*w for tomorrow.

Putting up a solar collector on the south side of the house - yippee!

 

[NutmegCT]

Thanks.

One of the issues with passive solar, especially here in New England, is to keep the costs low, and the efficiency high.

So ... either have a solar heat "dump" (the stone or water drums, etc.) or a solar collector that passes (conducts) the heat to air (or water if you're heating water).

So - stone or water, etc. for heat retention, metal for conduction.

In the south, your sun is pretty high in the sky during summer, so awnings will do a great job in shading all those windows.

 

[tony barnhill]

Wouldn't it be better if the collector was angled?

What's the price? Size? Manufacturer?

You gonna use it to heat space or to heat water?

 

[tony barnhill]

Tony - sun here is very low in winter.

Price, about $35.
Size: 8' w x 7' h
Manufacturer: me (I built it)

Deciduous tree to the south, so it's shaded in the summer, full sun in winter.

Heats the kitchen and dining room. Sun heats the black screening inside the clear cover. Air rises inside the box and enters kitchen through upper vents. Thin plastic anti-backflow flap in both vents.

Convective flow pulls cool air from kitchen floor into the box through the lower vents, then up through the screen and into the kitchen through the top vents.

Warmed air entering kitchen is around 120-130F in full sun, around 80-90F on a cloudy day.

T.
_________________________
1959 TR3A - "TeeYah"
Commission: TS47527L
Engine: TS48235E

 

[tony barnhill]

Way cool Tom! (or should that be HOT?)
_________________________
Dave Reese
Vist my web pages!
TR3B - TCF120L - "Fagin"

 

[tony barnhill]

<span style="font-size: 17pt"> <span style="color: #FF6666"> <span style="font-weight: bold"> PLANS!!! </span> </span> </span>

 

[tony barnhill]

Plans? You don't know me very well, do you ...

I'm a cobbler! A retired teaching living on $1200/month!

The open wall space (no cabinet blockage) inside the kitchen on that south wall is about 8x7 - so the box outside is 8x7. You need intake vents that equal about 50% of the box width. Same for output vents.

Built a simple box frame (8x7) of 2x4's. Screwed 1x6 sides, and 1x8 top and bottom, onto the 2x4's. Caulked between clapboards and frame.

Run black aluminum screening from the bottom (attached to the clapboards) to the top (attached to the top outer edge of the frame). That way the rising air has to pass through the heated screening to reach the top vents.

Tack 1x2's across the outside of the box, one vertical, one horizontal. These support the clear plastic sheeting.

Finish by tacking 3.5 mil clear plastic sheeting across the box; reinforce the edges by tacking 3/4" molding onto the 1x edges.

Voila!

If you have to buy all new materials, might be over $50. Heaven forbid! So I scrounge what I need from the garage, cellar, workshop, and "town recycling center" (the dump). Only new thing I got was the $6.99 roll of clear plastic sheeting. (10' by 100').

Got the idea from Mother Earth News:

https://www.motherearthnews.com/Renewable-Energy/2006-12-01/Build-a-Simple-Solar-Heater.aspx

Tom
a/k/a Frugal Zealot

 

[tony barnhill]

Plans? You don't know me very well, do you ...

I'm a cobbler! A retired teaching living on $1200/month!

The open wall space (no cabinet blockage) inside the kitchen on that south wall is about 8x7 - so the box outside is 8x7. You need intake vents that equal about 50% of the box width. Same for output vents.

Built a simple box frame (8x7) of 2x4's. Screwed 1x6 sides, and 1x8 top and bottom, onto the 2x4's. Caulked between clapboards and frame.

Run black aluminum screening from the bottom (attached to the clapboards) to the top (attached to the top outer edge of the frame). That way the rising air has to pass through the heated screening to reach the top vents.

Tack 1x2's across the outside of the box, one vertical, one horizontal. These support the clear plastic sheeting.

Finish by tacking 3.5 mil clear plastic sheeting across the box; reinforce the edges by tacking 3/4" molding onto the 1x edges.

Voila!

If you have to buy all new materials, might be over $50. Heaven forbid! So I scrounge what I need from the garage, cellar, workshop, and "town recycling center" (the dump). Only new thing I got was the $6.99 roll of clear plastic sheeting. (10' by 100').

Got the idea from Mother Earth News:

https://www.motherearthnews.com/Renewable-Energy/2006-12-01/Build-a-Simple-Solar-Heater.aspx

Tom
a/k/a Frugal Zealot

 

[tony barnhill]

WHOO-HOOO.....I can see one of those in every other window on this south-facing wall of my garage....so you have clear, corrugated panels covered by clear plastic?

 

[tony barnhill]

LOL - Tony - if you need heat in that garage, and all that glass faces south ... you wouldn't need *any* other winter heat source when the sun shines.

And I'd sure suggest some awnings or deciduous trees in front of the windows, for shade during summer.

Another thing to consider - add some sort of "heat collector" behind the glass that isn't used for the hot air boxes. The collector (cement blocks, black painted drums of water, etc.) acts as a thermal "dump", and would retain the sun's heat even after the sun goes down. Again, totally passive - no moving parts, and basically free.

Otherwise - go for it!

T.
_________________________
1959 TR3A - "TeeYah"
Commission: TS47527L
Engine: TS48235E

 

[tony barnhill]

I'm thinking starting with each corner window skipping every other & ending up with a double collector in the middle...a big sheet of plywood in the window inserts painted flat black.....& that's a good idea about some sort of passive collector behind the remaining windows (though not blocking them) to retain heat.

I've been trying to figure out some way to block heat during the summer - I'd initially thought about building some removeable window coverings out of black screen.

 

[tony barnhill]

& now we're back to NutmegCT's first post in this thread.......

 

[tony barnhill]

I'm thinking starting with each corner window skipping every other & ending up with a double collector in the middle...a big sheet of plywood in the window inserts painted flat black.....& that's a good idea about some sort of passive collector behind the remaining windows (though not blocking them) to retain heat.

I've been trying to figure out some way to block heat during the summer - I'd initially thought about building some removeable window coverings out of black screen.

Tony - I'm starting a new thread. Figure folks interested in temps didn't expect to read all this solar stuff.

If you're meaning to use the black painted plywood to heat the air, I'd really suggest you use black painted aluminum sheets - or even black aluminum screening. You need the air to pass along both sides of it, absorbing the heat that the "black" brings in. Unless the plywood is *really* thin, it's actually acting as a kind of insulator.

Plywood won't absorb and release the heat as efficiently as a sheet of metal.

Black aluminum screening?

 

[NutmegCT]

yep - aluminum (metal) conducts the heat. black increases the absorption. screening allows the air to pass *through* the mesh, rather than just on the front and back of it.

solid surface absorbs more heat, but is less efficient in conducting it to the air that you need to heat.

 

[tony barnhill]

K - so I get a roll of black aluminum scrteening & suspend in in my 'box'?

I've gotta get a copy of that Dec 2006 issue of <span style="text-decoration: underline">Mother Earth News</span>

 

[NutmegCT]

Tony - the complete article is in that link I gave earlier:

https://www.motherearthnews.com/Renewable-Energy/2006-12-01/Build-a-Simple-Solar-Heater.aspx

 

[tony barnhill]

You're right...I just had to find where I could view the photos & diagrams since the links didn't work....& I found it.

 

[aeronca65t]

Interesting reading all this.

~THIS~ is my passive-solar, direct-gain house (it's about a 20 year old photo, but it doesn't look much different today).

Back when only a few weirdos seemed to care about saving energy, the 39th president offered a program of low-interest loans to anyone building a solar house. While everyone else seemed to be focused on the sweaters he wore, I spend my time investigating the government solar program that he proposed.

Most of the homes at the at time were active solar, which did not interest me.
But then I read ~This Book~ (it had just come out). I decided passive solar was the way to go. The principle behind it is so simple and elegant.

I went to the store and bought a shovel and wheelbarrow...and dug the footings.
Every piece of wood, siding, wire, nails, screws, etc was put in it by me. I built most of it over two summers. Two of my neighbours helped me push up the third floor walls...that was the only "hired help" I had (I plied them with beer :laugh: ).

The primary glass windows are, of course, facing true south. There is only one small window on the north side. Decidous trees shade most of the house in the summer. It's all 2X6 construction and has a neat metal spiral stair case I built for the third floor rooms. The lowest floor is a garage/workshop. Floor in the workshop is thick concrete poured over styrofaom. All soil-covered block walls are styofoam insulated too. Use a high efficiency hot water baseboard backup heat (with oil...no city gas available where it is).

As a young, single parent, I raised three kids in this house. The kids have great memories of the place and still love it. They won't let me sell it. Since it's on a lake, it's our "lake house" (complete with rowboat). These days, we also have a very nice townhouse. The lake house serves as my base for my cars....the race cars and MGB will "winter over" at the lake house.
It's about 20 miles from the townhouse, so we're out to it all the time. At some point, we'd like to sell both places and buy one bigger place in the ~Morris County~ area.

After all these years of living in a passive solar house, it boggles my mind that it is still a rare thing to see.