tube type propane heat rather than electric?

[hbracing]

Does anyone have more info on useing propane tube heater instead of electric? As always picturs would be great but any info would be appreciated. I am starting a new oven and I have not seen much on the propane set up. Alot of the info on this forum will be put to use and already has been with the design. Thanks to all of you for the help.

[holeshot87]

i have a oven 6'x4'x4'. i use a torpedo heater and it works great. the oven heats up to 400 in around 13 to 14 mins. the heater go from 50,000btus to 85,000 btus. hope this helps.

[hbracing]

sorry about the delay but when you live in Nebraska pushing snow is a must. Being an ex-HVAC guy it hurts my head to think about the air flow. You have to have ventalation. I have a 55,000btu-150,000btu propane unit that would work nice as an alternate source. I am very carefully designing this thing and I want to work out the mistakes before I get to them. Any thoughts are more than helpfull and appreciated. Thanks again.........

[Aardvark]

IF you are facing the back wall of the oven I put the heater nozzle? at the bottom right corner of the oven using a welded stand that the heater sits on to keep the output horizontal and I put an 8" vent with damper (Mcmaster-Carr) in the upper left corner. It circulates quite well, apparently.....

Do not use extension tubes on the end of the heater to get the nose inside the oven....It will give it that nice jet engine sound that will bother the neighbors blocks away. (I have already done this experiment for you) The heated air needs to expand or accelerate so I put the nose just barely inside the oven chamber. Problem solved...

[hbracing]

Thanks for all the input. That makes sense. It vents as needed. I will be starting the project soon. I am in no hurry and will keep reading and adding to the forum. Again thanks for all the input............

[Mick40]

Won't the high volume of air entering the chamber be too excessive? How have you solved this? Baffles?

Mick

[hbracing]

I was reading an older post and they used baffles and dampers to keep the heat in but not keep so much back pressure that it would over heat the heater. I am going to build a 4x4x8 or bigger in the near future and I think I will try both ways of heating. I will be sure to pass on what I learn......

[sdold]

I would seriously consider getting at least borrowing a CO detector and keep it nearby when you try the thing out, since the fuel/air mixture might be altered by the airflow restriction. It might not be a problem, but I'd at least test it unless you are using it outside. The heaters need a certain amount of oxygen to combine with the fuel to give you CO2 instead of CO.

[hbracing]

exactly but you are not reuseing the air from inside the oven. It is constantly being fed from the outside. The heater sits outside the oven and blows in.
CO2 could be a problem no doubt but I think I will try it anyway with that in mind. Thanks for that bit of info I will certainly keep that in mind........

[sdold]

No, I just meant that since you are partially restricting the output, the input air will slow down a little too, so the fuel/air mixture might change a little. It might not be a problem.