Instructables
video Fresnel Lens pool heating option
Uploaded time: Oct 19, 2009 03:55 PM
This large spot Fresnel lens can be used as a direct heater focused on copper coils with active fluid circulation. This is the only reasonable option for heating a swimming pool with a Fresnel Lens. Pointing the lens directly at the pool water does not work. This requires a computer hard drive water cooling kit or regular copper tubing.

This is a large Fresnel Lens focused on a copper tube with a 12 V pump (powered by two 6 watt solar panels) with water circulating through the unit. Water, seven gallons, was raised from 63 F to 106 F in one hour. It is not super efficient as heat is lost at the open top of the glass tank. This is designed to illustrate one method of solar heating a swilling pool with a Large Fresnel Lens.
wic110 months ago
Connect it with sun following mechanism and set some termo circulation pipes under it. Free heat energy through whole the year.

Only think is ''how not to break it' wit the wind or gerater rain or sth :)
neo716651 year ago
The chemicals used in a swimming pool does some pretty bad stuff to copper.