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swfoam Posted: Dec 05, 2010 08:56 AM	Propane heater and SPF I have been using a propane heater to warm up the interior of a building before we spray, but have always shut it off before spraying. My question is, is it ok to leave it running while we are spraying? Is there any danger of it sucking up foam spray and catching fire or exploding? Thanks for your help and input
quentin Posted: Dec 05, 2010 11:32 AM	You need it OFF when spraying since you not only have the risk you mentioned but also the fumes from off gassing can be flamable. No flames, sparks or etc should be anywhere near when you are spraying and until after it is all aired out.
Daniel X Posted: Dec 05, 2010 03:26 PM	You're also introducing a TON of moisture into the building...
swfoam Posted: Dec 05, 2010 11:44 PM	How much water can there be in propane?
Brian Bothun Posted: Dec 05, 2010 11:53 PM	I was told 1lb. of propane burned adds 1lb of moisture to the air...If thats true im not sure but I know its alot.
John Shockney Posted: Dec 06, 2010 01:43 AM	As you all may know any liquid or gas fuel is a hydrocarbon that is it contains hydrogen and carbon when you burn or oxidize these fuels the waste or by products are CO2, CO, H2O, and some other trace gases. The only way to get away from producing H2O (water) is to burn a pure carbon fuel like coke made from coal by heating and burning off the hydrogen also charcoal is an almost pure carbon fuel. With the above info I can tell you that I have installed 95% furnaces and to get the heat on in a customers home we have ran the condensate drain into a 5gal bucket (at 5pm) only to find it ready to overflow by 9am the next morning. That’s a lot of water that any non-vented heater will dump into the air. You can overcome this if there is enough air exchange in the building to vent the moisture out but that defeats what you are trying to do (heat the building up) Hope this helps Thanks Airpro
SPFer Posted: Dec 06, 2010 02:33 PM	Look into using an indirect heater, like this one: http://www.amazon.com/HeatStar-Portable-Diesel-Indirect-Heater/dp/B000VHDS3I You can place the heater outside and vent the heat in, or place the heater inside and vent the exhaust out.
John Shockney Posted: Dec 06, 2010 04:22 PM	Wow, $3,000 For that kind of money I could buy three +90 propane downdraft furnaces put them on hand-truck carts vent them with 2inch PVC and run a garden hose for a condensate drain. No thanks Airpro
steven argus Posted: Dec 07, 2010 11:30 AM	Airpro, that's what we're building right now. My only problem is what fuel to use. I have a propane conversion kit to do away with the natural gas and venting the combustion gas outside is fine. Do you know how long a 100# propane tank will last? Also, is it O.K. to transport the filled tank on say a small trailer?
John Shockney Posted: Dec 07, 2010 09:40 PM	guiness There are a lot of factors in figuring propane consumption: how big is the space you are heating, the temp outside, how big the furnace is, windows, just about everything that’s on a heat loss calculation sheet. I can tell you that around 800-1000 gallons will heat 1800-2000 square foot through an Indiana winter, that is a house not foam insulated. Yes it should be ok to transport on trailer just look at the RV industry. Thanks Airpro
steven argus Posted: Dec 08, 2010 02:31 PM	Thanks Airpro. It's 20 degrees around here now. We like to have the building around 60 degrees so the sheathing will be at least 50 degrees. I'm hoping to get at least 3 - 4 days out of the 100 gal tank with a 2500 SF building.
Daniel X Posted: Dec 08, 2010 09:00 PM	There is no water in propane... H20 is a product of combustion. Time to catch up on high-school chem I guess.
SPFer Posted: Dec 09, 2010 05:35 AM	Airpro, I like your furnace idea, but what about the issues of having the unit in the area you're spraying? First of, it gets covered with foam, full of fumes and beat up. Also, do we need to worry about the flammability of it with the fumes? The nice thing about these indirect heaters is that they are completely out of the workspace and seem to last longer.
Daniel X Posted: Dec 10, 2010 03:25 AM	Put a shed roof over the furnace, run it outside and duct the heat in... Who cares if it gets beat up? Is this not a construction site you're working on?
John Shockney Posted: Dec 10, 2010 11:13 AM	There are a few ways that you could set this up but this is what I would do to keep it simple: 1. Use a down flow +90% furnace (most +90’s can be setup in any position) 2. Put 12-20inch legs on it and attach a hand truck to one side (no ductwork needed easy to move) 3. Run two 2inch pvc vents through a window one is the flue the other is the combustion air supply. Due to the sealed combustion design of a +90 furnace this will eliminate the danger of an open flame. 4. Install a 2-4 inch thick air filter on top to protect the furnace blower and heat exchanger from dust and over spray. This could be a HEPA filter if you want but I would use a stack of cheep fiberglass filters because they don’t restrict the airflow as much. 5. Use fuel rated hose to run the LPG in high pressure (10psi) to a low pressure regulator at the furnace (lets you run smaller hose if you leave the tank outside) or just set a tank of propane next to the furnace (KISS) one of the biggest problems is getting enough fuel to the furnace and with LPG you are boiling a liquefied gas off in a tank if that tank isn’t big enough and is outside in the cold it can freeze up or just not provide enough gas to the furnace. 6. Connect the condensate drain per the manufacture’s instructions and use a ¾ male PVC pipe adapter as a garden hose adapter and run this to a drain I know this may sound like a lot of work but it should be easy to set up. Also by filtering the air you are not trying to heat cold outside air. You could put the furnace out side and duct the heat in but I would not use a +90% because the water drain can freeze also to get enough air flow for a 100K BTU furnace you will need 18inch flex duct. I have ran this type of furnace on jobs where I was the HVAC contractor (most contractors won’t start up the furnace until the drywall is done because the don’t want to clean the dust and dirt out of the furnace because no one changed the air filter.) This works great the air filtration removes most of the smell and over spray from the building while spraying. Also we have found that when spraying in cold weather to follow the sun, that is start on the sunny side of the building and work to the cold side your foam will also heat up the building. I have sprayed open cell in 20deg weather with no heat in the building by just following the sun. Sorry to be this long, I have a hard time reading some of the longer posts let alone write one. Hope this helps Thanks Airpro
Posted: Feb 05, 2011 06:40 AM	300k heat wagon 10 degrees outside hit the site,, made heat in 15 minutes,, heat wagon outside,,ducted in,,,dry warm air didnt even have the winders covered,,, 10,500sq ft foot print,, tarping off quadrants,,,bringing quadrant up to heat,,and shootin it while tarpin of next one closed cell worked good in the cold,, thank you god!!! did i say there was 1/2" rboard on the exterior?

Author

Comments

swfoam

Posted: Dec 05, 2010 08:56 AM

Propane heater and SPF

I have been using a propane heater to warm up the interior of a building before we spray, but have always shut it off before spraying. My question is, is it ok to leave it running while we are spraying? Is there any danger of it sucking up foam spray and catching fire or exploding? Thanks for your help and input

quentin

Posted: Dec 05, 2010 11:32 AM

You need it OFF when spraying since you not only have the risk you mentioned but also the fumes from off gassing can be flamable. No flames, sparks or etc should be anywhere near when you are spraying and until after it is all aired out.

Daniel X

Posted: Dec 05, 2010 03:26 PM

You're also introducing a TON of moisture into the building...

swfoam

Posted: Dec 05, 2010 11:44 PM

How much water can there be in propane?

Brian Bothun

Posted: Dec 05, 2010 11:53 PM

I was told 1lb. of propane burned adds 1lb of moisture to the air...If thats true im not sure but I know its alot.

John Shockney

Posted: Dec 06, 2010 01:43 AM

As you all may know any liquid or gas fuel is a hydrocarbon that is it contains hydrogen and carbon when you burn or oxidize these fuels the waste or by products are CO2, CO, H2O, and some other trace gases.

The only way to get away from producing H2O (water) is to burn a pure carbon fuel like coke made from coal by heating and burning off the hydrogen also charcoal is an almost pure carbon fuel.

With the above info I can tell you that I have installed 95% furnaces and to get the heat on in a customers home we have ran the condensate drain into a 5gal bucket (at 5pm) only to find it ready to overflow by 9am the next morning. That’s a lot of water that any non-vented heater will dump into the air.

You can overcome this if there is enough air exchange in the building to vent the moisture out but that defeats what you are trying to do (heat the building up)

Hope this helps

Thanks

Airpro

SPFer

Posted: Dec 06, 2010 02:33 PM

Look into using an indirect heater, like this one:

http://www.amazon.com/HeatStar-Portable-Diesel-Indirect-Heater/dp/B000VHDS3I

You can place the heater outside and vent the heat in, or place the heater inside and vent the exhaust out.

John Shockney

Posted: Dec 06, 2010 04:22 PM

Wow, $3,000

For that kind of money I could buy three +90 propane downdraft furnaces put them on hand-truck carts vent them with 2inch PVC and run a garden hose for a condensate drain.

No thanks

Airpro

steven argus

Posted: Dec 07, 2010 11:30 AM

Airpro, that's what we're building right now. My only problem is what fuel to use. I have a propane conversion kit to do away with the natural gas and venting the combustion gas outside is fine. Do you know how long a 100# propane tank will last? Also, is it O.K. to transport the filled tank on say a small trailer?

John Shockney

Posted: Dec 07, 2010 09:40 PM

guiness

There are a lot of factors in figuring propane consumption: how big is the space you are heating, the temp outside, how big the furnace is, windows, just about everything that’s on a heat loss calculation sheet.

I can tell you that around 800-1000 gallons will heat 1800-2000 square foot through an Indiana winter, that is a house not foam insulated.

Yes it should be ok to transport on trailer just look at the RV industry.

Thanks

Airpro

steven argus

Posted: Dec 08, 2010 02:31 PM

Thanks Airpro. It's 20 degrees around here now. We like to have the building around 60 degrees so the sheathing will be at least 50 degrees. I'm hoping to get at least 3 - 4 days out of the 100 gal tank with a 2500 SF building.

Daniel X

Posted: Dec 08, 2010 09:00 PM

There is no water in propane...

H20 is a product of combustion.

Time to catch up on high-school chem I guess.

SPFer

Posted: Dec 09, 2010 05:35 AM

Airpro,

I like your furnace idea, but what about the issues of having the unit in the area you're spraying? First of, it gets covered with foam, full of fumes and beat up. Also, do we need to worry about the flammability of it with the fumes?

The nice thing about these indirect heaters is that they are completely out of the workspace and seem to last longer.

Daniel X

Posted: Dec 10, 2010 03:25 AM

Put a shed roof over the furnace, run it outside and duct the heat in... Who cares if it gets beat up? Is this not a construction site you're working on?

John Shockney

Posted: Dec 10, 2010 11:13 AM

There are a few ways that you could set this up but this is what I would do to keep it simple:

1. Use a down flow +90% furnace (most +90’s can be setup in any position)

2. Put 12-20inch legs on it and attach a hand truck to one side (no ductwork needed easy to move)

3. Run two 2inch pvc vents through a window one is the flue the other is the combustion air supply. Due to the sealed combustion design of a +90 furnace this will eliminate the danger of an open flame.

4. Install a 2-4 inch thick air filter on top to protect the furnace blower and heat exchanger from dust and over spray. This could be a HEPA filter if you want but I would use a stack of cheep fiberglass filters because they don’t restrict the airflow as much.

5. Use fuel rated hose to run the LPG in high pressure (10psi) to a low pressure regulator at the furnace (lets you run smaller hose if you leave the tank outside) or just set a tank of propane next to the furnace (KISS) one of the biggest problems is getting enough fuel to the furnace and with LPG you are boiling a liquefied gas off in a tank if that tank isn’t big enough and is outside in the cold it can freeze up or just not provide enough gas to the furnace.

6. Connect the condensate drain per the manufacture’s instructions and use a ¾ male PVC pipe adapter as a garden hose adapter and run this to a drain

I know this may sound like a lot of work but it should be easy to set up. Also by filtering the air you are not trying to heat cold outside air.

You could put the furnace out side and duct the heat in but I would not use a +90% because the water drain can freeze also to get enough air flow for a 100K BTU furnace you will need 18inch flex duct.

I have ran this type of furnace on jobs where I was the HVAC contractor (most contractors won’t start up the furnace until the drywall is done because the don’t want to clean the dust and dirt out of the furnace because no one changed the air filter.) This works great the air filtration removes most of the smell and over spray from the building while spraying.

Also we have found that when spraying in cold weather to follow the sun, that is start on the sunny side of the building and work to the cold side your foam will also heat up the building. I have sprayed open cell in 20deg weather with no heat in the building by just following the sun.

Sorry to be this long, I have a hard time reading some of the longer posts let alone write one.

Hope this helps
Thanks
Airpro

Posted: Feb 05, 2011 06:40 AM

300k heat wagon
10 degrees outside
hit the site,,
made heat in 15 minutes,,
heat wagon outside,,ducted in,,,dry warm air
didnt even have the winders covered,,,
10,500sq ft foot print,,
tarping off quadrants,,,bringing quadrant
up to heat,,and shootin it while tarpin of next one
closed cell worked good in the cold,,
thank you god!!!
did i say there was 1/2" rboard on the exterior?

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