Passive Solar Collector

[Flyin6]

OK, get to make the first post on the first thread in a brandly new (DOT Free) Board

Man I must be livin' right!

OK. so Wilbur sent me a link to passive and active solar collectors over in the Hide Site section. I looked that stuff up, and I was HA'd (Hillbilly Amazed)

Brain free stuff right there that keeps things thawed out and is low cost and builds easy. I have been wanting some easy in my life as of late.

So Here is a simple diagram for a passive solar collector panel which I'll build out of my favorite pink board, and use it to keep up upcoming above ground water storage "Box" free of the frozen little nasties that make me anxious and cost me money replacing lines, fittings, valves and things like that

[stlaser]

DOT'ed officially up, now it fits in..... ;D

[EL TATE]

Squirrel!

[OldKooT]

Looks kinda like a open window to me...maybe the drawing is too complex for me. As a farmer we don't draw stuff,  we just imagine stuff in our head, and then wreck stuff until it looks like what we envisioned.

The above mentioned....Given the flack some insensitive people on the internets have given you over your foam board color choices... may I suggest you use the pink for the hot side and the blue for the cold...so you can then say you just were making it easier to understand for the iternets in dem pictures you post.

[Sammconn]

That means he'll need to acquire a bit of blue too. Lol.
But seriously I've heard they work. I don't have, yet.

I will attest the gazebo at the cabin collects a lot of heat on a cold day.

[moto123]

A couple suggestions:
1.  You need to be able to seal off the solar unit from the room at night time.  Otherwise all your heat gained during daytime will be lost at night time when it gets cold outside and the process reverses.
2.  This system was designed to work with an existing double hung window.  For better performance, the cold return duct would be connected at the bottom of your conditioned room to pull the coldest air off the floor.  It would then be routed flat to the bottom of the solar heater.  This would require an additional floor or wall penetration.

[Flyin6]

A couple suggestions:
1.  You need to be able to seal off the solar unit from the room at night time.  Otherwise all your heat gained during daytime will be lost at night time when it gets cold outside and the process reverses.
2.  This system was designed to work with an existing double hung window.  For better performance, the cold return duct would be connected at the bottom of your conditioned room to pull the coldest air off the floor.  It would then be routed flat to the bottom of the solar heater.  This would require an additional floor or wall penetration.

OK, based on the little I have read so far: Responses in red

1.  You need to be able to seal off the solar unit from the room at night time.  Otherwise all your heat gained during daytime will be lost at night time when it gets cold outside and the process reverses.

This is true. However there are more factors to consider here. The first being the principal of therman mass. Big thick, dense things collect and store long wave radiation like sunlight and collect ambient heat or cold. Basically they work to egual the temp. So if a bit of warm air is circulating about the cooler thermal mas pulls in that heat.
Know what a good thermal mass collector is? A big tank of water is a great one. So the working theory in my unstable brain says that if I can use a big delta of heat over ambient during the day, to warm up the big thing which is a 330 gal tank of water, then that big thing will radiate the heat in short wave radiation for much longer...i.e. over the night. So open or close the clod would have a harder time making a big mass cooler, that the effort of collecting heat during the day that occurred.

2.  This system was designed to work with an existing double hung window.  For better performance, the cold return duct would be connected at the bottom of your conditioned room to pull the coldest air off the floor.  It would then be routed flat to the bottom of the solar heater.  This would require an additional floor or wall penetration.

I think I'll build mine a bit differently. I was thinking I'd have a port at the top which connected to the water tank box, and on the bottom of the unit run a few air duct lines which originates from the bottom of the water containment box. So, yes it requires openings in the top and bottom to work properly, with the lower inlet connected to the heated space to be most efficient

[Wilbur]

I think some of those pics are the exact ones I modeled mine after....got it from Mother Earth News.

I used one of those corrugated Plexiglas panels for the clear stuff, and plywood for the rest. I didn't have it all the way up into the window so I ran two small 4" stove pipes as the input and output. that went into a box I made for the window. I then just used louvered round vents for input and output and had them turned away from each other. The thing I found was that the air didn't move fast enough on its own so I put a small fan in (a small computer fan would work) for the output side (inside the box) to blow the hot air out, that also created the suction to pull in cold air. 

Like I said it would raise the temp of the air 70 degrees even with the fan on it which was pretty good. I was really proud of my invention and if my house didn't face directly south I would still be using it. But the wife thought it looked ridiculous and made me get rid of it. No sense of humor in some people.... ::)

I was going to move it to the side of the deck (I had originally built it to be turned on its side) but that's right by the furnace output blower so I decided that potentially killing my family probably wasn't worth it. I will likely install it in/on my shed which I want to use for some projects. 

[moto123]

Yes a large thermal storage (water tank) will hold heat.  But it will also hold cold, or lack of heat.  The same amount of heat energy that allows it to stay warm all night is equal to the amount of "lack of heat" that it also holds during the morning hours of the day.  The storage volume does not create heat, it only acts as a flywheel on the system, slowing down the rate of change.

None of this is related to closing off the solar collector at night.  That was just a suggestion to make it more efficient.  You would have to run a calculation to compare heat gained from radiation versus heat lost from conduction and convection to determine how much closing and then opening the ducts daily would help.  If you don't want to close off the solar collector, then make the collector bigger and insulate it very well.  The increase in size will output additional heat during the daytime to offset the loss of heat at night time.  This has nothing to do with storage volume, it is purely the difference between heat gained and heat lost.  We need to make sure the net result is positive heat gain.

[moto123]

The thing I found was that the air didn't move fast enough on its own

This is caused by the fact that the supply duct at the top of the collector is short.  If you were able to increase the length of this duct upward before the air outlet, you would see an increase in air flow.  This is due to the stack effect, also known as draft.  The same principle is applied to fireplaces and other appliances that heat air.  The farther the flue or chimney extends above the heat source, the greater the air flow.

[Wilbur]

The thing I found was that the air didn't move fast enough on its own

This is caused by the fact that the supply duct at the top of the collector is short.  If you were able to increase the length of this duct upward before the air outlet, you would see an increase in air flow.  This is due to the stack effect, also known as draft.  The same principle is applied to fireplaces and other appliances that heat air.  The farther the flue or chimney extends above the heat source, the greater the air flow.

That makes sense moto....I am ignorant on a lot of this part for sure!

Don here's a site (there's tons out there) that will help explain what the best angle of the collector should be for your location (presumably for winter given what you want it to do):

http://www.solarpaneltilt.com/

[OldKooT]

Don a thought based on some experience.... use oil not water. A tank full of oil....submerged say 4' or so with a heat exchanger in it...would absorb and maintain a lot of heat.

[Flyin6]

Don a thought based on some experience.... use oil not water. A tank full of oil....submerged say 4' or so with a heat exchanger in it...would absorb and maintain a lot of heat.

Norm, this is a water storage closet my friend...No oil gonna be in there, or I might hook it up to mamas shower...
Imagine the outcome of that?

BTW, had my eye out for a good hit and miss motor, but no Ci-Gar yet. I'll get one and be the proud owner of "Norm's Contraption" in the tucky

[Flyin6]

The thing I found was that the air didn't move fast enough on its own

This is caused by the fact that the supply duct at the top of the collector is short.  If you were able to increase the length of this duct upward before the air outlet, you would see an increase in air flow.  This is due to the stack effect, also known as draft.  The same principle is applied to fireplaces and other appliances that heat air.  The farther the flue or chimney extends above the heat source, the greater the air flow.

That makes sense moto....I am ignorant on a lot of this part for sure!

Don here's a site (there's tons out there) that will help explain what the best angle of the collector should be for your location (presumably for winter given what you want it to do):

http://www.solarpaneltilt.com/

Saw that already

Well say 40 degrees north latitude

And the rule says when facing south or a bit south west to be perfect, add 10 to your latitude and I come up with a 50 degree tilt angle to make good N' hot air for my cold water storage tanks

[Flyin6]

Found another diagram of this contraption:

[Flyin6]

And two vertically mounted units mounted to the side of a workshop: