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68c10airstream · 03-19-2017, 10:09 PM

Your furnace from a trailer is called a "downflow/counterflow". In a trailer there is not a basement so the furnace is installed in a closet and the air is pushed down through the floor to the ductwork that sits under the floor. I use the same style of furnace but i purchased new a sealed combustion model and it uses outside air for combustion, heats it up and exhausts the spent gasses out on a separate pipe. If i spill gasoline on the floor the fumes won't be pulled into the firebox and create an explosion!!

My furnace sits on a man made tin box with the opening facing out to the center of the garage. Code says that the burner should be a minimum 24" above the floor, which is where mine sits. Love the heat pouring out at my feet and it's safe.

Remember that if you pull in paint fumes, paint stripper, carb cleaner, etc, into the fire box it will rot out the heat exchanger. The heating industry calls it "haloginated hydrocarbons" (i learned the description in a grainger catalog). Basically it becomes almost a muffler in the fact that a fuel is being burned in a metal chamber that cools down and gets acids inside it and corrodes.

My career as a dealer mechanic of 30 plus years and 5 different locations revealed rotted out overhead modine style heaters in every garage. Carbon monoxide was the first indicator, followed by a flashlight looking at the backside near the fan and would always see flames through pinholes in the metal heat exchanger. Bringing this up to the owners usually fell on deaf ears.

I did some research in the 80's about this and found a local furnace business/installer that told me the story of free hanging modine style heaters would be rotted out in a YEAR in beauty salons. He got tired of warrantying the first heat exchanger and the next year replace the whole unit. This went on for 15 years until he installed a sealed combustion house furnace that pulled OUTSIDE air for combustion. It was a condensing primary and secondary heat exchanger unit made out of stainless steel. He said it was installed 5 years ago and not a service call. I then knew what i wanted for my garage. Mine has been in use every winter for 24 years and never a single problem. What is your safety worth??

03-19-2017, 10:09 PM	#11
68c10airstream Registered User Join Date: Mar 2013 Location: Marquette michigan Posts: 828	Re: garage heater Your furnace from a trailer is called a "downflow/counterflow". In a trailer there is not a basement so the furnace is installed in a closet and the air is pushed down through the floor to the ductwork that sits under the floor. I use the same style of furnace but i purchased new a sealed combustion model and it uses outside air for combustion, heats it up and exhausts the spent gasses out on a separate pipe. If i spill gasoline on the floor the fumes won't be pulled into the firebox and create an explosion!! My furnace sits on a man made tin box with the opening facing out to the center of the garage. Code says that the burner should be a minimum 24" above the floor, which is where mine sits. Love the heat pouring out at my feet and it's safe. Remember that if you pull in paint fumes, paint stripper, carb cleaner, etc, into the fire box it will rot out the heat exchanger. The heating industry calls it "haloginated hydrocarbons" (i learned the description in a grainger catalog). Basically it becomes almost a muffler in the fact that a fuel is being burned in a metal chamber that cools down and gets acids inside it and corrodes. My career as a dealer mechanic of 30 plus years and 5 different locations revealed rotted out overhead modine style heaters in every garage. Carbon monoxide was the first indicator, followed by a flashlight looking at the backside near the fan and would always see flames through pinholes in the metal heat exchanger. Bringing this up to the owners usually fell on deaf ears. I did some research in the 80's about this and found a local furnace business/installer that told me the story of free hanging modine style heaters would be rotted out in a YEAR in beauty salons. He got tired of warrantying the first heat exchanger and the next year replace the whole unit. This went on for 15 years until he installed a sealed combustion house furnace that pulled OUTSIDE air for combustion. It was a condensing primary and secondary heat exchanger unit made out of stainless steel. He said it was installed 5 years ago and not a service call. I then knew what i wanted for my garage. Mine has been in use every winter for 24 years and never a single problem. What is your safety worth??