Solar Heating Plan for Any Home

Hi Joe,
To be honest, I've not thought in detail about exactly how the thermal mixing valve works, but it does work well.
It allows you to set the loop out temp to just about anything you want -- for example, if the tank temp is 160F, the mixing value can be adjusted to produce 120F water. Its not limited to the 10F drop in temp over the loop.

The pump in my case is located a bit lower in elevation than the storage tank. If your pump is at a higher elevation than the storage tank, you will have to go to using a heat exchanger to extract heat from the tank. The pipe coil heat exchangers immersed in the tank are very commonly used for this. Alternatively, I guess you could locate the pump at the storage tank and use a check valve to keep the house loops from draining back to the tank when the pump shuts down.

Gary Reysa

Thank you for the detail. I love the concept of solar radiant heating and your case study provides structure to what I have been dreaming up.

One question was answered... if you add cold water through the thermal mixing valve, how do you keep all the additional cold water from overflowing your tank? Your answer, mix in cooler water from the supply loop as it returns to the storage tank.

That raises a few other questions.
1- Your circulation pump is located in the house. It "pulls" water from very far away. Is this a problem? You must be down hill...

2- Does the reduced cool-side supply loop water have lower pressure and is this a challenge for blending at the thermal mixer?

3- If your tank is at 155 and you only lose 10 degrees after the radiant loop, how effective is thermal mixing 145 degree water back into the 155 degree supply?

Thanks,
Joe Barfield
San Antonio, TX

Thank you for the detail. I love the concept of solar radiant heating and your case study provides structure to what I have been dreaming up.

One question was answered... if you add cold water through the thermal mixing valve, how do you keep all the additional cold water from overflowing your tank? Your answer, mix in cooler water from the supply loop as it returns to the storage tank.

That raises a few other questions.
1- Your circulation pump is located in the house. It "pulls" water from very far away. Is this a problem? You must be down hill...

2- Does the reduced cool-side supply loop water have lower pressure and is this a challenge for blending at the thermal mixer?

3- If your tank is at 155 and you only lose 10 degrees after the radiant loop, how effective is thermal mixing 145 degree water back into the 155 degree supply?

Thanks,
Joe Barfield
San Antonio, TX

Great article! I was wondering how many square feet your house was
and how often you need backup heat?

I saw this in the printed edition. I want to incorporate this
design into my house, once I move and get it built.

Good system. Vertical collectors will gain about 30% more heat in
the winter when there is snow cover on the ground through
reflectance. New snow makes a great reflector and it is free. A
vertical collector that is used for space heat also is
self-regulating in the summer since a fair bit of sunlight reflects
off the glazing, keeping the system from overheating. If it does
overheat, you can cover some of the collectors with canvas. Don't
use plastic. It might melt!!

i THINK THIS IS GREAT AND I AM GOING TO TRY IT THANX LAYTON

I really appreciate your doing this project. I think you have
something of value here and I will use your lead for my own solar
heating plans. Many thanks! Pls feel free to update me. Michael
Cresanta