bigdaddylee82
bigdaddylee82 UberDork
8/31/20 1:03 p.m.

Anyone have any experience with solar water heaters?  Specifically the panel style you'd put on the roof?

I'm looking at using them for a closed loop radiant floor heat system, and supplementing a domestic hot water supply.

Justjim75
Justjim75 Dork
8/31/20 1:09 p.m.

I'd like info as well

californiamilleghia
californiamilleghia Dork
8/31/20 1:49 p.m.

I would like to know how you mix the "too hot" water with the cold water to get it at a Hot shower temp ?

My black plastic camping solar heater works great but really gets the water too hot , with no way to regulate the temp !

I would like to put some panels on the roof but need to regulate the temperature.

Ideas ?

bigdaddylee82
bigdaddylee82 UberDork
8/31/20 2:01 p.m.

In reply to californiamilleghia :

I'm far from an expert, but most of the systems I've seen in my research, the solar is in a closed loop, and uses a heat exchanger to provide heat to the domestic water.  So the heat exchanger is taking the place of and/or supplementing your domestic water heater.

I've also seen folks use a more traditional tank style water heater, and circulate the domestic hot water through the solar collector before the water heater or circulate from tank water heater to solar collector back to the water heater.

rustyvw
rustyvw Dork
8/31/20 2:05 p.m.

I've been thinking about doing something like this to help heat my pool.  One of these days I will actually get around to doing it.

akylekoz
akylekoz SuperDork
8/31/20 2:11 p.m.

In reply to rustyvw :

My Father in-law ran a bunch of black plastic tube back and forth behind his pool for a few hundred feet then ran the pump through it, as far as I know it worked.  Seems that a it would feel more effective if the flow through the tubes was on a separate circuit and slowed some to let the water cook a little.

Stampie (FS)
Stampie (FS) MegaDork
8/31/20 2:56 p.m.
californiamilleghia said:

I would like to know how you mix the "too hot" water with the cold water to get it at a Hot shower temp ?

My black plastic camping solar heater works great but really gets the water too hot , with no way to regulate the temp !

I would like to put some panels on the roof but need to regulate the temperature.

Ideas ?

It's called a mixing valve.  You plumb in the hot water and cold water and it mixes it to a set temp.  Google "Solar hot water mixing valve".

Justjim75
Justjim75 Dork
8/31/20 3:04 p.m.

Is there anyway to use check valves and convection so the water circulates without any kind of pump?  I also considered solar powered pumping

bigdaddylee82
bigdaddylee82 UberDork
8/31/20 3:38 p.m.

In reply to Justjim75 :

You might be able to get away with that with a closed loop on the solar side, and a heat exchanger to whatever you're trying to heat.

You'd want a thermostat to control a pump(s) on the radiant loop.

I plan to have zones on their own thermostats.

mr2s2000elise
mr2s2000elise SuperDork
8/31/20 4:16 p.m.
rustyvw said:

I've been thinking about doing something like this to help heat my pool.  One of these days I will actually get around to doing it.

Did almost 2 years of research for it for my pool. When I re- did my pool this year, with the speed of solar heater, etc, I went to gas heater. Cost me $3700 total. With the gas bills I am getting, and lenghtening my swim season for kids, very happy with my decision.

84FSP
84FSP UltraDork
12/10/20 6:25 a.m.

The majority of Asia uses these units on all the higher rooftop appt's.  It amazes me that it never took root here.  Not sure it would be the only unit required for a larger "merican" home but a secondary unit to run most of the home maybe?

Placemotorsports
Placemotorsports Reader
12/10/20 7:11 a.m.

I was just thinking the other day about getting a solar panel to run the pool pump.  Shouldn't take that much juice to keep it going

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