Okie dokies, lets get started, firstly a little history lesson to Nobody in particular. I did not invent corrugation as that was done many years ago I believe by a Swiss Monk of Irish and Greek extraction named El Corridor Francisco de Ribbo while trying to perfect a automated noodle machine for an all you can eat reindeer fast food outlet in Lapland. Thus endeth the lesson.
These are passive solar panels that can be made by anyone with even the most basic skills, however don’t let the term passive fool you as the amount of heat produced by these panels can be quite impressive, as in enough to fry an egg. Therefore a few safeguards have been built in to prevent damage from over heating. The channels increase the surface area so that each 24" panel has a surface area somewhere in the region of a 48"x 96" flat panel. So two 24"panels =a surface area of some 64 square feet of Flat Black and that’s quite a lot. Now if you have ever tried to walk barefoot on a black surface like pavement in the summertime you’ll start to understand what I mean. Same thing applies here as the solar heat is let in but because of the thermopane shield none is lost back to the outside.
They work by convection and only in the daytime so are not designed or meant to totally replace conventional heat systems. These panels work by taking cool floor air heating it and then transferring it back into the house via the ceiling duct.
However my log house of some 3,500sq feet has these panels covering the entire south wall30’x30’ high with a peaked cathedral ceiling staged in pairs the dimensions of which are centre 24" wide by 3o' high staging down to 12’ and even at –40c on a sunny day NO other heat source is required during the daytime. As a matter of fact most of the time too much heat is conducted into the house in the winter and excess heat is dumped by means of a in duct fan into a insulated 8’x8’x30’ underground granite rock pit which is used to store heat. This stored heat is then transferred to the house during the night by means of a squirrel cage fan in my central heating system. These panels also work all summer to heat up the rocks in the pit. The rocks then cary enough heat to last for all but the worst winters Manitoba can offer.
This method however is not normally available to most town dwellers so it is best to consider these panels a supplemental daytime heat source.
The dimensions are as follows, 24"x 96"x 5" deep. per panel
½" plywood to make the containment box inside dimensions 24"x96"
2 sheets sealed Plexi glass although real glass is better as Plexi glass tends to yellow, however real glass is more expensive and is prone to hail damage. Therefore shutters would be advised.
High density Styrofoam 96"x24"x 5"
PVC tubing and connectors
Tin for in house ducts.
Tube silicone sealant for sealed Plexi glass unit and general sealing
One can urethane foam, available at any hardware store.
Flat black latex paint for painting Styrofoam channels.
Masking tape 1" wide.
Lacquer thinner or acetone
One spritzer bottle
Construction: The box
One open plywood box 25" x 96" no biggie
Strips of aluminum ¼" for sealed Plexi glass unit available at window manufactures, or simply have them make the unit for you.
Holes cut for entry and exit ducts ceiling duct 3"x 20", floor duct 20"x4"
Holes for connector ducts 4.5" round intake 4" outlet floor , 3.5" round intake 4" outlet
Tin intake and exhaust ducts floor duct 20"x4" ceiling 20"x 3" one each per two panels complete with mounting flanges available at any heating supply shop.
Cutting the channels in the Styrofoam, I used a large bed Cincinnati milling machine and a 5"cove cutter to mill the channels, this however is not a machine most do it yourselfers have sitting in the garage Soooo I have come up with a different method, several in fact.
1.Channels can be cut using a large router a jig and a large half round bit or a table saw with the Styrofoam set at an angle to the blade and making multiple passes.
2. Or using the masking tape starting at the edge of the foam lay strips spaced at 5" intervals, then using the spritzer bottle spray a small amount of lacquer thinner or acetone onto the surface of the foam. The acetone will dissolve the foam between the strips of masking tape, spray in stages and don’t use too much. Keep dissolving the foam to a depth of 2.75". This will give you a nice concave channel. And Please do this OUTSIDE, as braincells are hard come by, just ask any politician.
Now turn over the foam sheet and cut the end air transfer channels, these can be cut with a knife or saw , any gaps will later be filled with expanding urethane foam so make them a little larger than the PVC tubes.
Install the tin ducts into the box, remember each panel only has one duct either top or bottom, unless only one panel is used then it would have both intake and exhaust ducts.
Install the PCV tubes and the foam sheet, mark the tubes for cutting, remove tubes and using a jig saw cut the tubes to match the channels in the foam block.
Replace the foam block and using the Urethane foam seal the tubes in place.
Paint all foam surfaces Flat Black.
Draw a bead of silicone all the way around the edge then place a ¼" spacer around the edge of the unit.
Again draw a bead of silicone on top of the spacer and place the sealed plexi Glass unit on top.
Also seal the PVC tubes where they enter or exit the box with silicone.
Now simply cut holes in walls of house to match the two tin ducts and fasten panels to the outside wall with standard fasteners. seal around ducts with insulation.
A few more things, seeing that these panels put the warm air at the ceiling a ceiling fan is recommended to bring the heated air back down to the floor.
Also a in duct fan can be installed to reverse the air flow direction so that the heated air is exhausted to the floor but this simply brings in another step and a ceiling fan is cheap and is a good investment.
Earlier I mentioned some safeguards, these panels can get quite hot, even in the winter time, this is why light colored Styrofoam is used, if the temp gets too high the Styrofoam will start to melt breaking up the black paint and exposing the light colored foam underneath. Hence it is self regulating to a certain extent.
Also in the summertime these panels must be taken down or properly shuttered.
One final word of caution, NEVER join more than two panels as the heat produced is accumulative as the second panel starts off with some of the the heat of the first, This accumulated heat can become EXTREME,and a incoming temp of +80c on a sunny winter day is not uncommon, never underestimate the power of the sun.