Need advice installing a propane shop furnace

[sixdogs]

I just finished properly insulating my 42' x 60' pole barn that has a concrete floor. For heat I got a used propane heater-furnace that was in our town garage. I've seen plenty of these over the years but didn't pay much attention and now don't know exactly what to do and how to go about it.

Here are some pics. It's stored in a different barn.
. . . .

It has two bolts on the top so I could hang it from the roof truss with chains or what else? I've seen them hung with threaded rod as well but how would I mount it to the truss? The ceiling is now metal clad. I figure it needs to be up maybe 8 ? or 10 ? ft?. Is this right?

I had a elec line run that comes out at the top of the 12' wall. I'd like to run a wire from it to a thermostat below and keep the building at what-- 50 degrees? 55? Help needed and any comments or advice appreciated.

 

[Alan46]

I must say that’s a lot of sq.ft. to heat!

 

[ponytug]

@sixdogs If it were me, I'd go search the internet for the manual, but yes, the idea is to get them up high enough not to ignite things in front of them. Generally speaking, the greater the BTU output the greater the distance to other items, but similar Lennox heaters want 8' or more above the floor, and something like "...10' or more above the top of aircraft..." sticks in mind. Local AHJ may have additional ideas. As these are flame heaters, I'd want to be aware of dangers of solvents and gasoline in the same space for obvious reasons.

IIRC, they require flexible metal hose for the gas connection. (36"?)

All the best,

Peter

 

[sixdogs]

I normally store some diesel in a tank at the opposite end of the barn-- 125 gallons. Bad?

Do I want a "flame" heater or get a different one? I could easily find something. I also have a VAL6 radiant space heater for cold snaps. What are some sample names of non-flame heaters?

 

[CH4Ohio]

Bolt some perforated angle flat to the ceiling and into the trusses. If the spacing doesn't work out, get above the ceiling and screw some blocking between the trusses and then mount angle to that. (Just like a garage door opener is mounted to the ceiling.)

From there, you can drop down with vertical angle metal or bolt more angle to that horizontally with the L facing down to accept threaded rods.

I'd probably have 4 bolts into ceiling framing and suspend it from that using additional perforated angle or threaded rod.

Exactly how you do this depends on the orientation of your trusses vs ceiling material and the ribs on the material.

Does that help or am I missing the point?

How are you going to vent it? Unless you have a venting plan, you might want to reconsider using that unit. That's a Category 1. Needs to be vented vertically. I'd much prefer to run a horizontal vent out a sidewall using a category III heater.

Edit -- What I'm asking about the vent -- Do you plan to perforate the roof or vent it out the sidewall? The heater in your pictures will need a double-wall vent through the roof with a cap. I'd prefer a unit with a power vent and terminate through the side-wall of a pole building.

 

[nybirdman]

I had a very similar unit in my garage for 20+years.the heat exchanger finally burned out.That one is 150k BTU,should be big enough.
Mine had a standing pilot.New one has an ignitor.
I spanned two trusesses with 2x4 and used all thread rod to hang.That is a bigger unit,you may want to double up on the 2x4's;on edge with the rod between and a large washer.

 

[sixdogs]

Bolt some perforated angle flat to the ceiling and into the trusses. If the spacing doesn't work out, get above the ceiling and screw some blocking between the trusses and then mount angle to that. (Just like a garage door opener is mounted to the ceiling.)

From there, you can drop down with vertical angle metal or bolt more angle to that horizontally with the L facing down to accept threaded rods.

I'd probably have 4 bolts into ceiling framing and suspend it from that using additional perforated angle or threaded rod.

Exactly how you do this depends on the orientation of your trusses vs ceiling material and the ribs on the material.

Does that help or am I missing the point?

How are you going to vent it? Unless you have a venting plan, you might want to reconsider using that unit. That's a Category 1. Needs to be vented vertically. I'd much prefer to run a horizontal vent out a sidewall using a category III heater.

Edit -- What I'm asking about the vent -- Do you plan to perforate the roof or vent it out the sidewall? The heater in your pictures will need a double-wall vent through the roof with a cap. I'd prefer a unit with a power vent and terminate through the side-wall of a pole building.

I'm do not want a roof vent so I guess this doesn't work. I'm leery of the open flame thing. How do modern propane furnaces function?

The barn may already have insulation blown in the attic so I don't want to mess that up when mounting things.

 

[CH4Ohio]

You won’t damage insulation by mounting to the ceiling.

All propane heaters have a flame. Not a problem if mounted up high and vented.

Most modern heaters have the option of horizontal venting. That’s the way I’d go. Run CSST piping. You might find it cheaper to install 2 ceiling mounted heaters instead of one.

Look at the Mr Heater 80K units at Menards to get some ideas.

 

[oldtimer 66]

Ponytug is right. Get the manual for this heater. It should be on the internet somewhere and if not buy it directly from Lennox. My Reznor uses a standard vent. Your Lennox looks like it has a powered vent. So to understand and make the heater work as designed get the manual and a good furnace contractor to do the installation.

When I had my building built, the last 2 items I was to supply, were the 12 x 12 garage door and the heater. If I remember correctly the door was $1200 and the heater, Reznor F100, was $1800 installed somewhat. Now this is in 1991 dollars.

The door was a phone call. The heater was a little more involved.

My building contractor set up some scaffolding for me and the 3 of us including the furnace contractor, man handled the heater onto the scaffolding. They worked on other things and I volunteered to mount the heater.

This F100 is 97 lbs. by the manual. I used I think 2.0 x 2.0 x .25 angle and .25 x 1.50 for the verticals and smaller stock for the gussets. When I thought I was done I needed to add the diagonal and that made the mounting secure. I would need to set up a ladder to get exact dimensions but i don't think that is necessary. The Reznor manual gave mounting hole locations on the top of the heater but that was it. There was also a note about spacers so that the side panels can be removed. You maybe on your own for making a safe and secure mounting unless your furnace contractor has those skills. I wasn't sure about the height but I just measured it and it is about 9" 8" to the bottom of the heater. My building has 14' side walls. It's
mounted on a diagonal to cover a larger area of the building.

After I mounted the heater the furnace contractor did all of the hookups, gas, electrical, thermostat, vent etc.

This F100 heats a 30' X 40' half section of my 40' X 60' steel clear span building. When I had my own gas well I kept the half of the building at a very comfortable 68 degs year round but then the gas ran out. Then the furnace contractor converted it to propane and I went back to cutting wood. TaDa.

It has been a very reliable unit. My furnace contractor had to replace a ECO switch and the pilot tube. Other than than that is runs good. It takes an occasional thermocouple. Later

 

[dstig1]

There are versions of these that are sealed combustion and direct vented. I really prefer that in a shop environment

 

[ning]

How do modern propane furnaces function?

The flame goes into a heat exchanger; you can imagine there's a metal box that gets really hot because of the fire inside, and air is blown around the outside of that metal box and gets hot.

You get the hot air, but the exhaust that comes out of the hot box goes through an exhaust pipe to the outdoors, either through the roof or the side wall.

The more efficient the unit is, the more heat is transferred essentially through a series of hot boxes to the air that's passing by, so the resultant flue gasses are relatively cool.

Exhausting the flue gasses allows you to warm the inside of the place without filling it with CO & CO2; you'll still need a source of air but likely there's enough gaps in such a big building to allow entry of enough air for combustion.

 

[sixdogs]

I did find an installation for the model I have but my specific model variation appears to be superceded. Mine shows a vertical exhaust while the newer versions show a horizontal exhust.

 

[sixdogs]

The flame goes into a heat exchanger; you can imagine there's a metal box that gets really hot because of the fire inside, and air is blown around the outside of that metal box and gets hot.

You get the hot air, but the exhaust that comes out of the hot box goes out the pipe.
The more efficient the unit is, the more heat is transfered essentially through a series of hot boxes to the air that's passing by, so the resultant flue gasses are relatively cool.

Exhausting the flue gasses allows you to warm the inside of the place without filling it with CO & CO2; you'll still need a source of air but likely there's enough gaps in such a big building to allow entry of enough air for combustion.

Is that what sealed combustion is? The version I have is not sealed?

 

[kenmac]

I have hung them with all thread, unistrut. metal straps, etc,
it's going to be a challenge to heat that non insulated pole barn to 55 deg. in the winter.. Attempting to do so is going to eat a lot of propane.

Before I ever installed this heater, I would carefully inspect the HE for rusted out or cracked
Those round tubed HE's were very prone to crack, split at the tubing seems, and rust out on the bottom where condensate collects.

As far as height, you can install it as high as you like, code should be 18'' off the floor where flammables will be stored. But I'm sure you would want to hang it much higher to be out of your way. About 3-5 ft off the ceiling depending on ceiling height ... just remember, heat rises.

 

[MapleLeafFarmer]

you have an older version but these are some spec's for their newest that can give you some guideline re flue size etc..

 

[ning]

Is that what sealed combustion is? The version I have is not sealed?

Sealed combustion means that the air for the combustion is pulled directly from outside rather than from the room where the furnace is.
You'd want a sealed combustion unit if there was danger of fuel vapors or if the building was really well sealed.

 

[sixdogs]

I have hung them with all thread, unistrut. metal straps, etc,
it's going to be a challenge to heat that non insulated pole barn to 55 deg. in the winter.. Attempting to do so is going to eat a lot of propane.

Before I ever installed this heater, I would carefully inspect the HE for rusted out or cracked
Those round tubed HE's were very prone to crack, split at the tubing seems, and rust out on the bottom where condensate collects.

As far as height, you can install it as high as you like, code should be 18'' off the floor where flammables will be stored. But I'm sure you would want to hang it much higher to be out of your way. About 3-5 ft off the ceiling depending on ceiling height ... just remember, heat rises.

Barn is fully insulated.

 

[sixdogs]

So if I got a different or newer furnace with sealed combustion chamber I'm OK with my 125 gal of diesel fuel 50 ft away?

There is no way I'm cutting a hole in the roof for a vent. Sidewall is OK but not roof. That's just asking for trouble.

 

[kenmac]

Barn is fully insulated.

I was just going by the pic you posted. I didn't see the walls insulated is the reason for that comment

 

[kenmac]

So if I got a different or newer furnace with sealed combustion chamber I'm OK with my 125 gal of diesel fuel 50 ft away?

There is no way I'm cutting a hole in the roof for a vent. Sidewall is OK but not roof. That's just asking for trouble.

that heater will never ignite that diesel hanging from the ceiling. Most fuel vapors like gasoline being more flammable that diesel, are much heavier than air and gather closer to the floor. It would take a lot of gasoline vapors to be ignited by that unit heater up in the air