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How might I heat a basement space with solar heated water running through radiant underfloor tubing? Answered

I live in the northeast and have a basement meant to be used by the kids as a hang out and studio space. It's cold. I'd like to heat it cheaply and environmentally. My preference is to use radiant floor heating with hot water supplied by a solar water heating system. I need to build both. I've seen great ideas for heating the ground and upper floors but I'm snagged on how to adapt any of them to a basement space. Oh, and I have practically no budget at all - tubing to be purchased but most everything else scrounged/salvaged/adapted. Any helpful suggestions?


We have radiant heat running through our basement and although its a great heating system for the basement versus forced air, I would not advise this as a DIY project where you have to scrounge/salvage/adapt. You want to keep in mind that many homeowners insurance will become null and void for any damages that ensue from an uncertified home repair.

As QA said, the cost is also likely out of your budget as you will either have to dig up your floor or install a subfloor. Either method can become very expensive.

Perhaps you can look at installing some radiators instead. Most reno's are removing them for in-floor heating options, so the chance of getting some inexpensively is probably good. There is also a good wealth of information online in radiator heating that could help you in doing a project like this yourself.

Your budget really wont allow the use of in-floor radiant heat as you would either have to jack hammer out the concrete and re-pour the floor with the tubes laid in or build a subfloor to lay the tubes under. How about this? There are solar hot-air heaters that you can build from a south facing box with tubes (built from cans or whatever you can scrounge), all painted black and sealed with glass/plexi. Put the intake low to the floor and the exhaust somewhere above it. Then you can do a standard solar hot water heater with a heat retention barrel inside. If you fill the system completely (no air at all), then convection will circulate the hot water. (Remember, intake (cold) on the bottom, exhaust (hot) on the top or higher than the intake.) To make them more efficient, circulator pumps (fan for air, some sort of liquid pump for water) should be used. Put a dark detector on them to shut them off when there is no sunlight (no heating available). Search the web for these options. I know they are out there as I have personally seen them in the past. I have also provided links to dark detectors in previous questions here.

This combo will do 2 things: air will provide quick heat while the water system will provide longer heat for night time use. And once you get the basement heated, it will stay warmer longer and be easier to heat up the next day.

By the way, rug on the floor and cloth hangings on the wall will help insulate the area. Check local outlets, bargain stores, even Goodwill for inexpensive possibilities. And don't forget to seal up the windows as good as possible.


Apart from the larger height difference, you should have few problems working from guides for installation on the ground floor. The only special considderations are the larger height difference, and the fact that any water leaving the system may need raising to the level of the drainage. If anything, heating a basement should be a little easier than a normal installation, as underground the temperature remains more stable, so demand for heat is more constant.

Also, I've seen some installations in cold areas that use lengths of pipe a few feet underground to pre heat the water a little before it enters the heaters.