Melting Points of Conduit & Copper tubing

[drtodd]

Hi!, I want to build a Fireplace Grate Convection Heater. It is essentially a series of hollow tubes arranged to replace the regular cast iron grate that draw air in from the room and vent the heated air out the top into the room. Does anybody know the melting temperatures of zinc coated electrical conduit or regular copper plumbing pipe?? I'd like to build it out of something I wouldn't need special equipment to bend.
My email address is drtodd@att.net if anybody knows and can respond directly.
THANKS!!! :D

[Wgoodrich]

Sorry I misunderstood what you were seeking. I thought you were trying to build a grate to set in a fire place.

I now understand you plan to use the principle of heat rises using hollow tubes to promote heat to travel out of the fire place for convection.

Convection would work fine yet hollow tubes would likely become a chimney passing smoke into the room. If you pointed the tubes downward from the fire into the room you would be sucking air out of the room through those tubes into the fireplace.

If you pointed the pipes upward into the room from the fire you would be creating a chimney sucking smoke and fumes of the fire into the room.

I would still use the solid square solid rod or rebar but would use 1/2" which would pass heat more quickly than 3/4" solid rod. The solid rod would allow the rods to point upward to promote heat to travel into the room but not have the hollow tubes as a chimney to promote fumes and smoke to travel with those solid rods.

I would then use small 12 awg steel wire mesh type material as a blanket on the last 8 to 12 inches of the rods pointing from teh fire upwards into the room. This upward travel would use the heat rises principle but not promote the chemney affect concerning fumes and smoke. Then I would include the small wire mesh as a screen type design same as a radiator would be use to release heat from the engine of a car. The wire mesh would make more contact with room air allowing the heat to dissipate into the room from the small wire mesh screen design much like that radiater does.

Hope this gives you some ideas.

Good luck and let us know about the results from your project.

Wg

[drtodd]

Thanks for the reply!! What I want to try is to arrange the tubes so their bottom openings are OUTSIDE the firplace and only draw in fresh room air. The upper openings would similarly extend beyond the firebox. With some modifications to accommodate the firebox and flue, the tubes would basically look like the letter "C" with the intent of placing firewood inside of the convection grate.
Temperatures can exceed 1,800 Degrees Fahrenheit. Obviously, I would test and test and test with numerous CO detectors scattered about the house. I just think this would be a nifty way of gaining BTU's even during a power failure without the expense of $5K to properly install a good insert into the fireplace. Is there someplace I can go to learn melting points of some of the softer (easily bent) tubing out there like electrical conduit or copper?
THANKS AGAIN!! This is a great place for learning!!!!
Todd

[Wgoodrich]

Remember these copper tubes are not pure copper but an alloy mix of metals. I an unable to provide the melting temp of copper tubing. Suspect you will need to contact an engineer that may have that data for you. Seat of the pants says that what you are designing rigid conduit would work. Softdrawn copper will fail due to the excess heat. That is only a seat of the pants opinion though.

Sorry

Wg

[drtodd]

Thanks a lot! I appreciate your help. I'll give it a try on a pilot basis with just a couple of tubes wired into my existing iron grate.
take care and thanks again!!
Todd