Apricus water heating tubes provide all the hot water for the house, including the hot water for the radiant floor.
The tubes absorb the sun’s radiant heat in an insulating layer of air-evacuated glass. A vacuum is an excellent insulator, allowing LEAFHouse to make hot water even when it's cold outside.
While the outside of the tubes are cool, the inside the tubes can exceed 300º F. There is a pipe connecting the tubes to various appliances that require hot water throughout the house. The tubes eliminate the need for an electric or gas water heater.
Our system features a tankless water heater, the Stiebel Eltron Tempra 20. Maryland’s average yearly “insolation,” or amount of sunlight available to make hot water, is 3.98, which is a little low as compared to a sunny place like California at 5.4. This means that, especially during the winter months, when insolation is low, the backup water heater will be doing its job.
Image courtesy of Apricus.