Propane Powered 4x4x4 booth *HELP*

[averyindustries]

Hey guys im new to this forum. Just picked up all my 1/8" steel and angle to make a solid 4x4x4 box. Im going to use hightemp insulation from lowes.

My dilemma is...

Should i used a forced air propane heater/ torpedo
HVACR > Heating Equipment > Portable Gas Heaters > Heater, Torpedo,Lp : Grainger Industrial Supply 100,000 btu
HVACR > Heating Equipment > Portable Gas Heaters > Heater, Torpedo,Lp : Grainger Industrial Supply 150,000 btu

OR

Propane powered Infrared Heater.
HVACR > Heating Equipment > Unvented High Intensity Infrared Heaters > Heater,Infrared : Grainger Industrial Supply 30,000 btu
HVACR > Heating Equipment > Unvented High Intensity Infrared Heaters > Heater,Infrared : Grainger Industrial Supply 60,000 btu
HVACR > Heating Equipment > Unvented High Intensity Infrared Heaters > Heater,Infrared : Grainger Industrial Supply 90,000 btu

Im not spraying powder in my booth only baking the objects in it. For spraying im constructing a frame from PVC tube and using thick clear plastic walls with a hepa filter and fan hooked up. Then transfering the part into the oven so i dont have all kinds of particles in the air.

I used the btu calculator ( BTU Calculator provided by the heater shop .com )
My settings were:
Good insulation/Tight leakage
Temp increase: 400
square footage to heat: 4 Feet by 4 Feet
Ceiling Height: 4 Feet
----------------------------------
BTU 16,000

Average insulation with same dimensions and heat:
BTU 32,000

Poor insulation and loose leakage:
BTU 64,000

Its going to be insulated with hightemp 1500+ F insualtion from lowes/homedepot.

Option one:
The problem i see with the torpedo propane blower is it blows it at 400CFM. well in an enclosed spaced with no vents i dont see how that will work to great. Even if i did vent it most of the hot air would escape. i would most likely have to use more then one unit to superheat the box initially then use a single unit to keep the heat up. This sounds like a pain in the A$$ and lots of propane wasted. I personally dont think ill go this route.

Option two:
Infrared Heater. I like this idea a lot! i dont have a massive 400cfm blowing around and i dont have to worry about venting it. It seems like this would be the obvious choice. Since heat rises i would mount it beneath the steel box upside down, letting the heat rise up. Sounds like more of a normal oven. Im just wondering how i can evenly distribute the heat. Hopefully it doesnt have a damn thermostat on it so i can leave it cranked up to reach 400 degrees.

Dayton: I could save a few hundred bucks and hit up the cheaper brands at lowes and homedepot but im going to be building and using this for some time so i want the quality right now, even if i have to pay a bit more.

Please help me out, like i said electric is out of the question this puppy needs to be portable

my email is sales@avery-industries.com

My cell number is 253-617-5753

Please contact me via email or repost on the forum, i will be taking hundreds of pictures of the full build and posting them on this site (if allowed). I think it will help others as well to jump on the wagon to make there own ovens! thanks guys hope to hear from you soon!

Jeremiah

[averyindustries]

Help me out! Tomorrow im going to be tempted to order up the 30,000 btu infrared unit. if i have good enough insulation and it is sealed well do you think i have head room (btu wise) for a larger steel box or should that be perfect? Let me know!!!!!!

thanks guys.

[averyindustries]

If my average temp of my garage is 70 degrees and i want to hit 450F maximum do i add the numbers together to get 520 for the calculator? or subtract 70 degrees from 450 to get 370...

Im tempted to get the 30,000BTU infrared unit but if i need the 60,000 unit i have the cash. i just need someones advice on which to use.

"c-k-racing" posted:

Freezer Conversion:
''Don't do like i done and say you just want the oven to heat up to 400* and be done with it. You'll need to subtract the room temp. from the hightest temp. you want to reach. and put that into the Fahrenheit temperature increase spot''.

[averyindustries]

HVACR > Blowers > Small Centrifugal Blowers > High Temperature Blower,115 Volt,227 CFM : Grainger Industrial Supply

Also im going to use this blower above to circulate the internal air. I think with good insulation and proper air circulation i can pull off using the 30,000 BTU infrared.

One major problem that i have no clue how to do but im sure many of you know how is:

How do i hook This unit. HVACR > Heating Equipment > Unvented High Intensity Infrared Heaters > Heater,Infrared : Grainger Industrial Supply Up to a thermocouple control unit so i can make it reach 400 degrees and actually keep it at 400? If i could get some kind of thermocouple to a device that could be set to a certain temperature then to control a relay to turn on and off the unit when 400 is reached etc?

Let me know!
Jeremiah

[averyindustries]

Dayton specs.

Gas-Fired Commercial Infrared Heaters

Ceramic material heats to approximately 1780 DegreeF (high intensity) and generates large amounts of infrared radiation that is directed to the floor. Noncorrosive aluminum and stainless steel construction. Bright aluminum reflector. Electronic ignition,100% automatic gas shutoff control, and mounting chain set included. Units are preassembled and ready to install. Installation information: Heated area requires 4 CFM of exhaust ventilation for every 1,000 BtuH of infrared heat (e.g. 120 CFM for a 30,000 BtuH heater, 240 CFM for a 60,000 BtuH heater, and 360 CFM for a 90,000 BtuH heater). Heaters must be mounted at a 20 Degree to 35 Degree angle from horizontal, preferably facing inward around the perimeter of heated area. CSA Certified.
* Uses: For high ceiling applications and areas with large heat losses. Widely used for total or spot heating in factories, warehouses, service garages, foundries, etc.

* 1/2" NPT gas inlet; 120V 60 Hz power required
* Water-resistant circuit board on 120V models
* Chain hanging set included

With that much insane heat this box is gonna get hot really fast, so im deff going to need some type of contol module to tame the beast so it doesnt burn my powder!!

[ed_denu]

You may not get a lot of responses to your questions here. If you do a search for propane or gas heaters you will find that there have been few responses to these type questions. While the very large commercial ovens all use gas as the heat source, most of the people posting on this board use electric heat.

From what I understand about gas fired ovens, which is very limited, they all use some type of heat exchanger versus direct firing into the oven.
I'm not sure how the heater you are referencing could be safely converted for oven use. Enclosing this type heater into an oven configuration and not letting the unit cool naturally as it is designed to do by hanging in open air could create serious safety concerns IMO.

Your idea of using a thermocoupler and a PID to control the temperature via a relay in theory should work. This assumes that you can somehow connect directly to the heaters controls.

Lastly, in your first post you state in option 2 that you don't need to vent it. If you read the specifications you posted in your last message you will see that the 30000 btu heater requires 120 cfm ventilation.

[holeshot87]

i use a torpedo heater (propane) to heat my 6'x4'x4'.i use a adjustable one 50,000btu's to 85,0000 btu's. works great. it gets to 400 in around 12 mins. if u need more inform. email me or call me.

[FigureLLC]

we use a propane oven. it's an under-floor burner. i'd be tempted to try the ir over the torpedo, bc of the cfm requirement. like ed, i'd fear burning up the ir heater with limited ability to cool it. if i were to build an oven with one, i wouldn't mount it on the bottom facing up. i'd mount it towards the bottom of the back wall of the oven facing forwards, with all but the open face of the unit exposed to shop air to help cool it.

[averyindustries]

Hole shot can you post some pics of your Pc booth? The torpedo pushes pushes out nearly 400cfm, do you let all that air out of your box or do you bottleneck to the vent to only let 200cfm out etc etc. Im just confused how people force air into a sealed box.

[averyindustries]

Ed posted
"Lastly, in your first post you state in option 2 that you don't need to vent it. If you read the specifications you posted in your last message you will see that the 30000 btu heater requires 120 cfm ventilation."

i took this two ways. either the unit itself needs 120cfm to cool off, or the workspace needs atleast 120cfm of fresh air flow so you dont die of poisening! Which one is right is beyond me haha.. Im thinking of mounting the unit like Len from Figure Engineering, LLC suggested. On the back wall near the bottom. the rear would be exposed and i would cool it via an external highcfm fan. So with proper insulation will the 30,000 btu IR heater be enough?