The place I moved to in San Marino has a swimming pool, a deck, a grill, outdoor couches, and a kegerator. Everything one would need to throw great summer parties. But, whenever we throw a party, few people jump in the pool. Why? Because it’s much too cold! The beautiful oak trees that shade our deck, also do a great job of shading our pool. So only in the warmest summer months is our pool decent to swim in. I’m not a big fan of personal swimming pools in general. But if we have it, and are paying for the weekly maintenance, we might as well make is usable.
I decided to solve the problem in the most environmentally friendly way I could: a solar water heater. Solar water heating has a strong history in Pasadena. In 1897 30% of all homes here had solar water heaters installed. Sadly, they’re not common today. I can’t change the public behavior, but I can put one on my own roof!
I was inspired by a story of a guy building his own home, and constructing a make-shift solar water heater so he could shower after a day in the Florida heat. It seemed very straightforward to build. I started pricing things out and discovered that copper was just a little too expensive. However as I priced it out, it seemed that this plastic, store bought solar water heater would cost about as much, and will work right out of the box. It seemed like a no brainer.
The solar water heater claims to raise the temp of the pool 5-10 degrees. The warmer we can get our pool the better! It also requires a pump. I didn’t want to tie it in with the existing pool pump, as that only runs a few hour during the day. I found a surplus dishwasher pump which claims 10gpm of flow. After a little plumbing, it could be just the thing. I liked the idea of only pumping if the panels were warm, and leaving it off at night. For at night, the solar heat collectors would act as radiators and give off heat instead of taking it in. I have plans for an automatic relay that turns the pump on only when it’s needed. But, for now I can make do with plugging it in manually.
More plans, math, and pictures coming!