PDF File has just been attached to this post for viewing of my system case anybody is interested in checking it out.
I run a simple solar drainback hot water system at my house.
I'm using 2 evacuated tube collectors - 20 tubes each.
Drainback tank is a used 6 gallon electric water heater.
My returning collector water returns to the small drainback tank then splits off into a Y pipe which feeds 2 seperate hot water storage tanks with built in heat exchangers.
1 tank is 33 gallons for domestic hot water use. Heat exchanger is a tank inside another tank design which 'stinks' as far as time it takes to heat the domestic hot water up.
The other tank is 45 gallon superstor used tank with built in coil heat exchanger in the bottom.
This tanks heats up much quicker and holds temps better then the other 'tank in tank' design.
I use this 45 gallon superstor tank hot water for my heat distribution.
My 33 gallon tank water is connected directly to my Propane fired Tankless water heater and works super when someone is drawing hot water for a shower. The tankless burner hardly ever comes on but for a few seconds now and then during the shower time.
My other 45 gallon tank of extra solar collected hot water goes directly to a 14 ft Runtal heater installed in my family room and that Runtal kicks out tons of heat with water temps as low as 90 to 110 degrees which I was amazed at after installing it.
If you do not have the option of installing radient floor or radient wall heating for whatever reason consider looking around for a used Runtal radiator. They are made out of steel... hold very little water and do an absolute beautiful job for heating.
I installed a timer on the taco variable speed pump that sends hot water to the Runtal. I've got it set up to come on for 1/2 hour then off for 1/2 hour.
If I start off with water temps around 125 to 131 degrees I've been able to get 7 hrs or so heat out of the 45 gallon tank.
So far I've been turning it on at night just after supper time say.. between 6pm and 8 pm.
It runs to about 12 midnight.. shuts down and comes back on at 4am in the morning. From 4am I let it run till around 7am. By that time the water temps are down to around 89 degrees or so..
I picked up the 12 inch tall by 14 ft LONG Runtal radiator off Craigslist for $75.00 (no kidding...
New these radiators are over $1500 bucks. Had to sand and paint it in a couple places but no leaks anywhere.
I used 1/2 inch pex to run from the 45 gallon hot water storage tank to the radiator because the radiator fittings were 1/2 inch in/out. What a nice radiator this is. I am always looking for more on CL for other areas of my house.
I attached a pdf file of my DIY solar hot water system showing the 2 tanks... collectors on roof etc. in the event anyone would like to check them out.
(4.38 MB, 24 views)
Pat B. Warwick, Rhode Island Rest Assured! Comments and/or suggestions I make here at the forums on 'your' projects as well as my own have all been carefully and scientifically calculated by the 'seat of my pants'