DIY hx

Eric Johnson

I have a 205K btu/hr wood gasification boiler out in the barn and a 1,000 gallon epdm-lined tank in the basement. My original plan was to try to store and recover heat in the tank with a flat plate heat exchanger (pumped from both sides), but I've abandoned that idea in favor of a more traditional in-tank copper arrangement. Two hxs actually--one on the top for recovery and one on the bottom for storage.

I want to build it out of 1" rigid copper, which I have about 200 feet of. Anybody know where I can find specs and designs that would allow me to move ahead on this project?

I know hot rod builds some pretty neat looking rigs for solar and wood heat. Presumably some of the other pros on this site do similar nice work.

BTW, I have two lines coming off the boiler--a 1" and a 3/4." The 3/4 incher loops through a greenhouse, so it's not involved with the tank. So we're talking one 1" line supplying maybe 150K btu/hour max, I'm guessing. Also, there's no solar component or DHW coil involved. I just need a good way to get lots of heat into the tank and lots of heat back out.

Larry C_13

HX

One method I have seen is to use the pipe inside of a pipe method. Take a 9'6" length of 1" pipe and solder a 1" x 1" x 1" Tee on each end. Now take a 10' piece of 3/4" pipe and slide it thru the first tee, all the way thru the 1" pipe, and out the other tee. Solder a 1" to 3/4" reducer to the outside of the 3/4" pipe and the 1" tee outlet at each tee.

Now you have single pass 3/4" inlet-outlet by 1" inlet-outlet heat exchanger. Insulate well and mount on a couple sheets of plywood.

You can series a couple of these on a wall to increase the surface area between the seperate fluid streams.