An overview of how a Solar Thermal system works - Solar Domestic Hot Water (SDHW)

A solar thermal system heats water through harnessing energy from the sun.  This is a sample setup of a solar thermal closed loop system - the most common system in use in climates where freezing may occur:

1)  A Solar Collector such as flat plate or evacutated tubes (most efficient solar collector on the market) collect energy from the sun in form of direct sunlight, ambiant air temperature, UVA, and / or UVB.

2)  The heat is transfered to a transfer medium such as food grade glycol (water is the most efficient transfer medium but food grade glycol is used to prevent freezing in cold climate conditions)

3)  The food grade glycol is circulated to a heat exchange system (commonly a coil in a tank that has your domestic hot water).  The heat from the food grade glycol is transfered to your domestic hot water.

4)  This pre-heats your hot water for your usage and can be heated if necessary by your existing auxiliary heat (electric or gas) to the temperature required.

5)  As you can see, this can be a significant savings for your electric or gas bills.

How many evacuated tubes are required for your Solar Thermal system?

System sizing depends on usage but here are rough guidelines for the collector size - we can size the heat exchangers, tanks, etc. for you on review of the project requirements:

• Domestic hot water - 20 evacuated tubes for 2 to 4 people or 10 tubes per resident (dependant on usage)
• Swimming pool - 3 tubes for every 10 square feet of surface area (indoor or covered outdoor pool)
• Radiant Heating floor - 1 to 3 tubes per square feet of heating area (Radiant heating floor is recommended with heating a pool or spa so excess heat in the summer can be beneficially used)
• Hot tub - 30 to 60 tubes for approximately 400 gallons

For information on how to get started with your Solar Thermal system click HERE