Evacuated Solar Hot Water Tubes

The  Evacuated Tube Solar Heating System is a breakthrough in the efficiency of hot water production for residential and commercial uses. The tubes, similar to the inside of a thermos, are placed in the sun. Being round gives them maximum sun exposure at every sun angle during the day. Also,  because of the vacuum chamber between the two walls of the tube, the tubes remain cool even in bright sunlight and, most importantly, the tubes can still produce hot water on cloudy days.  They are very superior in performance in cold weather conditions. A flat plate collector would radiate a lot of the generated heat through the single panel glass. The Evacuated Tubes work with a vacuum so this doesn't happen.

How the Evacuated Tubes Work

Sunlight heats round aluminum heat sinks that runs the length of the tube. A small copper tube is located in a slot in the aluminum. Inside this tube are drops of glycol which change to steam that goes up the tube and into the manifold where the water changes state from steam to water. It is this changing of state from water to steam that gives the tubes the high efficiency that makes them produce about 40% more heat than a flat plate collector.

Heat transfers from the heat tube end into the water flowing through the stainless steel manifold.

The Evacuated Hot Water System

This evacuated tube hot water system contains 24 glass tubes or 30 with the stretch version.  There is also one extra tube and all the components including the manifold frame and component assembly necessary to put together the tube system. It does not include pumps, expansion tank or other accessories.  We can provide all this necessary equipment but you would have to contact us to help you design a solar hot water system.

One of these 24-tube hot water systems usually provides enough hot water for an average family of four.

After the frame is attached to a roof, it is easy to slip each tube into its slot in the manifold while the bottom gets attached to the bottom rail. Hence there is no heavy lifting required as the tubes get installed one at a time. (Water must be flowing through the manifold when the tubes are installed.)

The evacuated tubes can be connected to a radiant floor heating system as the temperature output is perfect for Pex tubing.

The tubes are made out of a glass similar to Pyrex (Borosilicate glass) and they are breakable but once they are installed on a roof they should give many years of service.

Federal Tax Credit

There is up to a $2,000 Federal Tax Credit available for up to 30% of a solar hot water system that is used for domestic hot water or space heating. The evacuated tube hot water system is qualified for the rebates requiring SRCC  certification.

There is a pilot Solar Thermal rebate program that has started in San Diego for California customers.