Simple efficient heat exchanger design...

Mark Eatherton

I am sure many people have seen variations over the years. This can be made with any size of copper tubing, and obviously, size does matter:-)



Nibco use to manufacture a fitting called a heat exchanger tee that was missing the tube stop that has to be ground out of the run of the reducing end of the tee. No longer made. With the invention of the tee drill, it becomes even easier to make these things up.



It is entirely possible to set this up as a low loss header/heat exchanger for those ugly non oxygen barrier situations where a person needs both, a LLH and a HXer.



I have the necessary calculation forms to determine square footage available based on water temps and flows if anyone is interested.



Enjoy



ME

hot_rod

enhance them

with corrugated copper tube from Wolverine. The Butler Solar HX and the outdoor wood boiler companies offer them with HX specific corrugated tube inside.



But for the cost of small plate hxers these days??? Unless you are using it for double duty.



I remember some early solar heat exchanger tubes built like that, some used an entire 20 foot stick of copper for a long version.



A tapered reamer is another way to remove the "stop" in fittings, or a die grinder if you have a steady hand.



hr

Mark Eatherton

Agreed...

One potential application I can see would be as a thermosiphon exchanger for a solar DHW system. For each foot of this exchanger (3" shell, 2" tube) you get 1/2 square foot of highly conductive heat exchanger area.



I know that the copper craftsman in you wants to build one just to check it out and see what it does :-)



Me too.



What I'd REALLY like to find are some old Noranda double augmented heat exchangers like Novan use to utilize on their modules. That little bundle of copper could kick some SERIOUS btuh.



If I were to use this as a heat exchanger for double duty, I'd probably increase the barrel size to 4" just to insure low pressure loss through the shell.



A local firm (Dr. John Proctor) from around here use to use the 3/4" with 1/2" for solar DHW preheat.



ME

Keith Johnston

Is there any reason it should not be used as a greywater Heat Exchanger?

I have looked at buying a greywater heatexchanger, and found most models were for 3 or 4" drains. My shower drain is 1 1/4 and runs straight down the same wall that encloses the cold water feed. Is there any reason I could not make one of these out of 1 1/4" and 2" pipe(type L or M, not drain quality, forgive my ignorance of the proper terms), with the drain water flowing through the middle of the 1 1/4" and the cold water feed between the 1 1/4 and 2"? Would there need to be a special adapter to connect the 1 1/4 drain pipe to the 1 1/4 pressure rated pipe?

Thanks

Keith Johnston

Homeowner with 3 teenage daughters