Designing (& Testing) A Solar Regenerated Desiccant Air Conditioner for our Passively Heated Solar Home, by Henry Gurr. This is the sixth of a series of nine photos. Please see the first in this series (pix 16/76) for full explanation.

This photo shows the solar collector (4’ wide X 24” long) positioned on our sun heated roof. The collector is hard to discern: But look closely, it is the deep groove part (covered with translucent plastic polyethylene sheet), that is raised up ~6’ from the rest of the deep groove roof, seen on both sides of the collector.

NOTE: The collector and the roof itself, are made of the same deep groove galvanized sheet steel roofing sections, a close up of which you see in bottom center of the photo.

You see a 4” dia white plastic pipe, angling down from the left side of the collector. This conducts sunny day hot air from the solar collector, into the 4’ x 5’ x 6.5’ plywood box, you see at upper left. This hot air flows through ~250 lb of wood sawdust in the box. The sawdust is the desiccant. The box is raised up ~20” from the ground, so an old air conditioner centrifugal blower, can be located, under the box. The blower has sufficient pressure to circulate air from the atmosphere, into (and through) the collector, through the pipe, through the sawdust, and exhaust back to the atmosphere. There are two valves, each two way, to switch air flow between night operation, and day operation. (One of these two-way valves is seen in subsequent photos.)

At night, additional 4" pipes bring air from the house, and circulate it into the blower, thru the desiccant to be dried. This same old air conditioner centrifugal blower, (now valved differently), has sufficient pressure to circulate air from the lower level of our house, into (and through) the sawdust, and thin return (the now dried air) back into the lower level of our house. Then the air moves (from and back into) our house by underground 12” culvert pipe, the entrance of which is under the center of the box: This provides for close pipe connection, and the box keeps rain out of the culvert pipe. The next three photos show more about how the air pipes & valves are connected, and how the weight of the box is supported.


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