Throughout the day the sun heats cold water circulated through a 31-gallon
solar water panel
mounted on the roof. The solar panel delivers hot water to an electric tankless water heater
( TWH ) by preheating the cold-water flow into the TWH.
The on-demand Stiebel Eltron Tempra 24 Electric Tankless
Water Heater ( TWH ) supplies hot water instantaneously on demand to shower baths and sinks,
eliminating a water heater & tank, and reducing natural gas usage. The TWH also lowers its
electrical power use by drawing pre-heated hot water from the rooftop solar panel rather than
heating cold water from scratch.
The on-demand Argo AT-1226 Electric Boiler ( Tankless )
heats water in pipes in the slab foundation to provide radiant heating for the house.
A setback thermostat
controls the settings to a peak of 60o for heat during the day and evening,
and 55o degrees during the night. Combined with roof and wall insulation, the ambient
temperature in the house is a comfortable range from 65o to 72o year-round.
Even on the hottest days the temperature does not exceed 80o.
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