(02-16-2020, 11:56 AM)tgalarneau Wrote: I have been using a solar collector hot water system for going on 15 years. It works fine for my family of 4.
It was designed for simplicity. I use a 70 gallon hot water tank to store the hot water and a single large Sun Earth collector on our 2nd story roof. We use a single El Cid 10 volt solar pump and dedicated 10v solar panel instead of the electronic controls (expensive and prone to controls failure) to pump water to the roof collector. It pumps fast when sunny and slow when cloudy and at night off. Just what is needed to produce solar hot water.
Hot water is available around 90% of the time and the highest temp it reaches is around 125 degrees but with the cold water mixer valve I control the tap water at 110 degrees or less. I tried a cheap propane on demand heater but the inconsistent temps made it worse than cold water. And our catchment cold water is around 80 degrees.
The only thing I would change would be for a larger 100 gallon hot water storage tank. This, I believe would give me hot water 99% of the time. I would probable use 2 of the small Earth Sun collectors instead of 1 large as they would be easier to handle when need to replace or move.
Of course needs are different dependent of number of people and types of showers. And guests can destroy the best laid plans.
Thanks for the clever solar pump suggestion. Sounds perfect for circulation.