plastic barrel as radiator
 

I need a affordable way to make uses of the hot water, I'm able to make and store now. I need a way to release the heat of the hot water into two rooms forming a L shape. One idea I'm considering is 6, 30 gallon, 114 L plastic barrels. One placed in each corner. All placed in a loop with the storage tank. Water pumped from storage tank goes to first barrel that flows to the next barrel and so on till the last barrel drains back to the storage tank.

I'm hoping to keep the working temp of the water at about 130 - 140F , 54- 60C in the storage tank but i guess warmer than room temp will work.. Low enough the barrels won't melt.

During warm weather the barrels could be drained and stored.

What you think?

Sounds affordable and easy. Dunno how appealing to the eye you can make it, but it should work. I'd also be unsure that its enough surface area to dissipate enough heat. You'll find out quickly enough though. :)

Car radiators would have more surface area, take up less space, require fewer plumbing fittings and be able to take the pressure, last time I bought a new radiator for my Honda it was around $60 but it seems like you should be able to find a larger cheaper one from an American car, or buy some used ones.

Auto radiator or heater core good idea. So much to do. The pump that was working so well on the rocket stove died of an air embolism today. Now I need to find some 12 VDC pumps. That can handle 140F - 60C.

Radiating heat...
 

130 to 140 F... I don't know what the source of your heat is, but it could fall lower than your numbers.

You'll know when you try it.

Heat output from a radiator depends largely on the difference in temperature between your room and the temperature of your heat source.

Hydrocarbon heaters burn really hot (the heat plenum sees about 450 F), so a fairly small radiator can heat a fairly large space.

Cars get pretty hot too. The fluid in the radiator is under pressure, so the heat is above boiling. And they have some way to keep the air moving. But they have a larger difference in temperature, so in your case, you might need more than a few radiators.

Heat pumps operate in the range you are citing, so what works for them might work for you.

Heat pumps usually have a fan constantly moving air past the radiator, might work for you.

Some heat pumps use really large radiators. In fact, one strategy is to make the entire floor into a radiator. This is called radiant floor heating... this way, if the radiator (the floor) is properly built, you don't need fans and you'll be able to get the heat you need from a lower temperature source, such as you have.

If you look into this, you need to understand that most radiant floors use gas or oil or electric as the heat source, and have a higher difference in temperature. If you are going to be working with 130 to 140 F water, it is a special case, and most rules of thumb will not apply. You'll need to put your water pipes closer together.

An idea I'm looking into is using hot water solar panel cores as radiators, rather than absorbers. I was able to find ten of them for not much money.

Regards,

-AC_Hacker