Mr Heater 75K BTU issue

[fitch]

* I think I posted incorrectly earlier* Please see below.

Mr Heater struggles with heating my 24x40x10 Pole Barn. I have the ceiling insulated but not the walls and the heat coming from it is not very much. Prior to buying, I spoke with technical service at Mr Heater and it was suggested I go with the 75K btu and it would heat fine without the walls insulated. Had it professionally installed and the furnace did not perform well so I had another service tech out and he suggested putting a 100 gallon tank down (formally ran it on a 100# tank) and a ceiling fan. Still not working well. In fact, the thermostat barely moves and still need to break out the Carhartts. I do understand insulating the walls would help, but the heat coming from the furnace is very weak. Thoughts?

 

[rustyzman]

Just a thought here, but are you having a regulator issue perhaps? I have had issues with bad regulators in the past that caused low output on stoves, heaters, grills, etc.

I had to replace the old regulator I was using on my old 30k vent free that I put on my new 50K Big Maxx unit this winter because of low heat output. It was rated at 100K BTU, but it was not providing enough fuel for the new 50k. Went with a new two stage regulator on a 100lb tank, now have no issues at all. Much improved output.

Might be worth a quick look.

BTW, mine is smaller, with walls light insulated but most of ceiling not insulated. Even in the 0 degree weather we had, I could get it up to 50-55 after a couple hours running. I don't keep it heated all the time, just when I am out there so it takes a while to get everything up to temp. One of the best upgrades I ever did, wish I did it years ago.

 

[D45]

Was the valve pressure inside the heater properly adjusted?

 

[fitch]

Would I contact my propane company, (they set the tank and regulator was on it) or heating and cooling tech?

 

[D45]

HVAC place can check and make sure the valve pressure inside the heater

 

[fitch]

I'm not sure about the pressure valve inside. I had the furnace installed by a heating contractor.

 

[D45]

Had it professionally installed and the furnace did not perform well so I had another service tech out.......Still not working well.......

So two places later, it is still not working?

Professionals eh?

Did you call either place back and say you are not satisfied with the install or the work performed?

 

[fitch]

I didn't call them back. They left me with,"the walls should be insulated". Maybe the third times the charm.

 

[fitch]

The furnace is now about 3-4 years old and maybe I need to look at a higher BTU... Reznor, Modine....

 

[D45]

Insulate it

1,000 sq feet should be fine for a 75K

I have a 75K in my shop, which is around 1,000.........my walls are insulated but I have an open in-insulated ceiling. I can get the shop to 68 degrees, no problem

 

[yeldogt]

What is the start temp of the space and how long does it run?

How much air is leaking in ?


I had 2x 100gallon tanks for my 40k unit in PA. you need enough free area above the liquid in the tank -- what does the propane co say you need to properly run 75k in the winter?

 

[ForceFed70]

I have the same heater. I also think you should just insulate the building. It'll be money better spent vs upgrading to a larger heater.

75K BTU is what's going in, you're getting something like 55K BTU of actual heat coming into the garage (rest goes out the exhaust). It doesn't feel like much when it's blowing down on you.

My garage is 32x40x12 and my heater has no problem keeping up. I keep it turned down to about 45* unless I'm working in there. Takes about 1hr to raise it to 60*.

 

[fitch]

As far as insulation, I was going to do 2" foam board between the 2x4's that run horizontal (purlins?) but then, spray foam isn't that much more. Just a lot or work to get everything off the walls so that the company can spray. Is the foam board an option? The ceiling has about 12"-15" blown in.

 

[ForceFed70]

Foam board would certainly be better than nothing. If spray foam isn't much more I'd be very tempted to go that route.

 

[fitch]

Pic of heater set up.

 

[yeldogt]

What's the ceiling insulation?

You did not answer my question -- but if you are trying to heat a cold space ... say from 20 degrees ....... the air out from the heater is not going to feel warm.

also -- metal buildings typically leak a lot of air -- so you are heating the outside

 

[fitch]

Ceiling has about 12"-15" blown in insulation. I only run the heat when I am going to be out there. I don't know how cold it is when I start the furnace. I guess the answer would be whatever the outside temperature is which varies in Michigan -10° to 40° ish?

 

[bobbyjean]

fitch- is it set up on one 100# tank now and the tech suggested another?
if you are able to,close gas supply and remove the cap at bottom of riser to unit....check in there and also check the burner tubes/orrifices...spider's like to hang in them sometime's...may need an air compressor to clean the burner tubes...check chimney as well.
as far as insulation for walls...your set up exactly as i was...i did the cut/cobble with foam board between wall girts...air sealed everything ...then put another layer of foam board on top of that...finished with osb....lot's of work for r-10...but it's working very well.
If you try the one inch foam board you will find it "slides" behind posts as well as corners... gonna be snug...a small block of wood and a hammer and you should have great result's-my 30/32/10 took 60 sheets...

 

[fitch]

I am set up on 120 Gallon tank now. I was on 100# cylinder. When you put the foam board over top the 1" foam board you put between the girts, did you frame it or just nail the board to the girts? What size foam board did you use? And last, what did you attach the OSB to? Thanks

 

[Gerry347]

With having bare steel walls I bet you're blow the heat right out of the building and it can't keep up. I would 100% insulate the walls before doing anything else. You won't be disappointed in the long run.

 

[bobbyjean]

fitch- i made a "story " pole and used screws into wall girts...then i used osb to finish...didn't want to waste space to frame out...i made nailer for bottom and top ....just ripped 2x in half. 1 inch foam board from lowe's(green).
osb attched to wall girts with 2.5 inch screws.
for the foam board between the wall girts i air sealed everything with "great stuff",also took roofing nail's tacked into girts top/bottom...just enough to hold ...should have taken some picture's.
i live next to a farm so mice are an issue....i used steel wool that i found on amazon and shoved it in around posts...in exterior corner's...even in underside of roofedge(think i was supposed to get a sealing strip for that)did that to keep bug's out.
i wanted to close gap between wall and concrete floor....a friend recomended sikka....self leveling sealer....worked great,wear glove's for sure if you try it ...it won't come off