SOLAR THERMAL SYSTEM

Heating water for bathing, laundry and cleaning can account for up to 70% of an average household’s gas bill. Installing a solar hot water system allows homeowners to significantly reduce their total energy consumption, saving money and reducing pollution of the environment.

A properly selected, sized and installed system will provide years of ongoing savings and eco-friendly, maintenance-free performance. A solar hot water system is the natural complement to any full photovoltaic system, providing even more energy savings by utilizing the natural, renewable power of the sun, and even alone serves as an important first step to lowering your utility bill and living green.

Drainback Solar Thermal Systems

In a drainback system panels are installed on your roof and use the sun’s energy to heat water, rather than glycol. This water is then used in a heat exchange to transfer heat to water used in the home. To keep from freezing, a drainback system incorporates a gravity-fed mechanism that drains the fluid from the system when it’s not in use. The drainback system contains everything needed –the sensors, controller and pumps along with the tank and heat exchanger.
Here is one possible design and list of components of a drainback solar thermal system.

1/6. pressure relief valve

2/15. temperature sensors

3. Solar panel (collector)

4. Mixing valve

5. Temperature gauge

7. Flow meter

8. Pump – to storage tank

9. Heating element (back-up)

10. Differential solar controller

11. Existing hot water tank

12. Heat exchanger

13. Pump – to solar panel

14. Water reservoir – flows into panel when in use and sits in tank during drainback