What's new
What's new

OT - Shop insulation

If you tried to heat 100% with wood, you would use 17 cords (oak) per year. I didn't even factor in the lower efficiency of most wood boilers, which would make that number 20-40% higher...

That's a LOT of wood, wouldn't leave much time to run a shop.
Gonna buy a tow behind chipper, chip it right in the woods, and store the chips in a silo, auger/blow it into the boiler.....:D
 
Consider you have gradient heat loss if you do not seal that lid and walls. A good shop will get hotter as height increases without major loss.

This is a good point, On top of my mezzanine (about 9' AGL) it's easily 4-5 deg colder. Should get warmer as I go up! I do have the 2 Big Ass fans set to push air down from the ceiling for the winter, I reverse them in the summer.
 
I had a 5,000 Sq/ft shop in Bemidji MN. One of the coldest spots in the country regularly. All of the big Car companies have their cold wweather test facilities located there. It was stick framed, R-19 Walls w/R-50 blown cellulose in the 12' flat ceiling. It had 6 big 4x6 windows down one wall that were dual pane, but not sealed thermopanes. I heated it with about 500 gal propane per winter with a 90K BTU furnace in the middle of the shop with no ductwork. We would get better than a week straight of -40 below zero every year.

I never thought I would have this trouble heating this building.

If I was to go spray foam, Do you think they would be able to foam it over the fiberglass/vinyl sheet or would I need to strip it all out? If that's the case it won't happen because that would be a frigin' nightmare.
 
I have read at one time it was cheaper to run a pellet stove on dried corn then wood pellets. Slight modifications needed for the feed machinery.
Bill D
 
I had a 5,000 Sq/ft shop in Bemidji MN. One of the coldest spots in the country regularly. All of the big Car companies have their cold wweather test facilities located there. It was stick framed, R-19 Walls w/R-50 blown cellulose in the 12' flat ceiling. It had 6 big 4x6 windows down one wall that were dual pane, but not sealed thermopanes. I heated it with about 500 gal propane per winter with a 90K BTU furnace in the middle of the shop with no ductwork. We would get better than a week straight of -40 below zero every year.

I never thought I would have this trouble heating this building.

If I was to go spray foam, Do you think they would be able to foam it over the fiberglass/vinyl sheet or would I need to strip it all out? If that's the case it won't happen because that would be a frigin' nightmare.
I live in Canada.... its cold here. and my heating on something 1/7th the size is only $30 in gas in the winter when its constantly below zero all day and -10 to -30C at night. Also only keep my shop at 50F when im not in it.
sounds from all this you have one heck of an air leak going on, most likely going right out the doors and roof.
 
I have read at one time it was cheaper to run a pellet stove on dried corn then wood pellets. Slight modifications needed for the feed machinery.
Bill D
There was a time that was true, and it will return. But now, between the drought and Ukrainian war, corn is near record highs.
 
Ok Guys - Question I do not have much experience with..

I was thinking about the propane boiler. I know when they put it in, they had to convert if from natural gas to propane. Is it possible that they didn't change an orfice or something that would massively lower it's effiency? I'm not sure which orfice is bigger, Nat gas or propane, and I don't know if the unit would even run if not converted or not done correctly.

Also, Looking at the calcs posted, the boiler would be running pretty much non-stop. During the day it seems to run about every 3-4 hours for about 60 min. Don't have a way to monitor it at night. But for the massive amount of consumption is it even possible for it to use that much propane in that amount of time?

Also I know I don't have a propane leak because the tank sat all spring/summer and our short fall this year and didn't pressure drop at all.
 
Ok Guys - Question I do not have much experience with..

I was thinking about the propane boiler. I know when they put it in, they had to convert if from natural gas to propane. Is it possible that they didn't change an orfice or something that would massively lower it's effiency? I'm not sure which orfice is bigger, Nat gas or propane, and I don't know if the unit would even run if not converted or not done correctly.

Also, Looking at the calcs posted, the boiler would be running pretty much non-stop. During the day it seems to run about every 3-4 hours for about 60 min. Don't have a way to monitor it at night. But for the massive amount of consumption is it even possible for it to use that much propane in that amount of time?

Also I know I don't have a propane leak because the tank sat all spring/summer and our short fall this year and didn't pressure drop at all.
I would have someone come out and look at it because, yeah, none[OK most] of us are not mod con boiler installers
In the 10 seconds I looked at that boilers specs, it looks like there might be information available[web enabled ISTR?] on how it is running
It modulates so it should try to run low and long, so if it actually shuts off it is has been running on low for a while. IIRC propane orifices are smaller[high pressure] than NG. Boy I would think a sophisticated boiler would know better.
Redneck way is smell the exhaust, should be pretty much water vapor. Clean as a whistle zeeeeero soot. Temp leaving the boiler needs to be under 160 degrees[blind guess] for plastic pipe

I am not naturally suspicious, ok, maybe I am, but tracking your propane levels and comparing to deliveries might be called for.
We get the little ticket from the truck here.
 
8000 square foot is no small shop. So this is four normal sized homes? How much does it cost to heat your house per month?
Think maybe 17 cords of oak might not be enough.
Propane makes more heat per unit but around here its cost per unit is much higher.
Have a pig up north. Same sized house with about the insulation. One of these is much more expensive.

Long ago dad sent me to classes on solar heat.
Turns out the trick is crazy insulation and sealing, double entry doors and small triple pane windows. How much loss when the UPS man walks in the door?
I have 11,000. Last week got cold but not crazy. Teens at night and good wind.
I was eating 80,000 BTU per hour so now we are going after those leaks.
Goal is heat with a handful of candles.
Bob
 
Last edited:
One of the things about large buildings is that they use less energy per square foot than a small building
That is because you do not heat space.
You replace the heat lost through surfaces. Plus leakage
A 480 square foot building [20x24x8] has 2.46 square feet of surface[walls and roof] for every square foot of floor space.
A 4800 square foot building[48x100x8] has 1.49 square feet of surface for every square foot of floor space.
Even when you make it a 16 foot wall[which in house terms is a 2 story, doubling the space], it still has only 1.98 square feet of surface per square foot of first floor space.
It is called the small building penalty in the green building world
Leakage per square foot tends to be worse in a small building, as it still has two doors and a bath and kitchen vent etc.
The OPs building has two over head doors and two man doors, and mine also does but is a fraction of the space, so my leakage per square foot is in theory, worse
 
I would have someone come out and look at it because, yeah, none[OK most] of us are not mod con boiler installers
In the 10 seconds I looked at that boilers specs, it looks like there might be information available[web enabled ISTR?] on how it is running
It modulates so it should try to run low and long, so if it actually shuts off it is has been running on low for a while. IIRC propane orifices are smaller[high pressure] than NG. Boy I would think a sophisticated boiler would know better.
Redneck way is smell the exhaust, should be pretty much water vapor. Clean as a whistle zeeeeero soot. Temp leaving the boiler needs to be under 160 degrees[blind guess] for plastic pipe

I am not naturally suspicious, ok, maybe I am, but tracking your propane levels and comparing to deliveries might be called for.
We get the little ticket from the truck here.


I get the tickets too, Many times I'm in the shop and I"ll go out and bullshit with the delivery guy. Don't think there is anything hinky going on there.

I don't think there is any soot as it's just out the side of the shop with a pair of 90's like a periscope. I would think I would see something on the building. Should the exhaust be thick white? If it was a diesel, I'd say it has a couple bad injectors:) (or bad rings) Seriously I get a ton of white vapor out the exhaust, I always thought that is just water vapor. I know there is a seperate condensate line.

As far as the boiler goes, I don't know what I don't know. I put a call into the company that installed it, haven't heard back yet.

Do you think i'm barking up the wrong tree or could there be an issue with the boiler I'm not thinking of? I know there is no way I'm getting 900 CFM of air moving thru the shop as your calcs say.
 
8000 square foot is no small shop. So this is four normal sized homes? How much does it cost to heat your house per month?
Think maybe 17 cords of oak might not be enough.
Propane makes more heat per unit but around here its cost per unit is much higher.
Have a pig up north. Same sized house with about the insulation. One of these is much more expensive.

Long ago dad sent me to classes on solar heat.
Turns out the trick is crazy insulation and sealing, double entry doors and small triple pane windows. How much loss when the UPS man walks in the door?
I have 11,000. Last week got cold but not crazy. Teens at night and good wind.
I was eating 80,000 BTU per hour so now we are going after those leaks.
Goal is heat with a handful of candles.
Bob

Bob,

My house is setup the same way, it's stick framed 4,200 sq/ft. ICF Basement (walkout) single main floor above . 2x6 Walls w R21 Insulation, Ceiling is blown Cellulose at R45 (ish). Hydronic heat in basement floor, and about 1,200 sq ft upstairs is also hydronic. Same NTI FTVN boiler, Combi for domestic hot water, 150K/BTU. I used 80 gallons of propane in the same time period, including, heating, domestic hot water, (2 teenagers showering) Clothes dryer, and range.

That, I'm cool with!

As far as heating with wood, I don't think I'd mind if I can get a wood boiler that I can stoke in the morning and when I leave at 8 or 9 pm. We only have pine realistically in the area, I'm told that Larch is the best species to burn, but no where near oak.
 
Bob,

My house is setup the same way, it's stick framed 4,200 sq/ft. ICF Basement (walkout) single main floor above . 2x6 Walls w R21 Insulation, Ceiling is blown Cellulose at R45 (ish). Hydronic heat in basement floor, and about 1,200 sq ft upstairs is also hydronic. Same NTI FTVN boiler, Combi for domestic hot water, 150K/BTU. I used 80 gallons of propane in the same time period, including, heating, domestic hot water, (2 teenagers showering) Clothes dryer, and range.

That, I'm cool with!

As far as heating with wood, I don't think I'd mind if I can get a wood boiler that I can stoke in the morning and when I leave at 8 or 9 pm. We only have pine realistically in the area, I'm told that Larch is the best species to burn, but no where near oak.
There could be something up with the boiler. There are a LOT of setting on a modulating boiler, I don't know how many of them could burn this much extra fuel. I would think if you don't have soot and the exhaust is not too hot, you don't have a major problem. If you are burning fuel, the heat would have to go somewhere or not be extracted.

Understanding where the leaks are would also help answer your question if spray foam can be applied to the batts. You want to make sure what ever you do seals up your leaks, so you need to know where those are.

I think you should probably look for a pro to do a blower door test. They will be able to tell you exactly how much infiltration you have, that way you can make an informed decision on where to spend money.
 
Something to think about regarding your last option:

Going with a full liner panel will be terrible for the sound deadening that you're currently getting with the vinyl and fiberglass. Got a friend that did it in his shop, looks great, but can't hardly have a conversation in it because it's always so loud. Something to think about.
 
I get the tickets too, Many times I'm in the shop and I"ll go out and bullshit with the delivery guy. Don't think there is anything hinky going on there.

I don't think there is any soot as it's just out the side of the shop with a pair of 90's like a periscope. I would think I would see something on the building. Should the exhaust be thick white? If it was a diesel, I'd say it has a couple bad injectors:) (or bad rings) Seriously I get a ton of white vapor out the exhaust, I always thought that is just water vapor. I know there is a seperate condensate line.

As far as the boiler goes, I don't know what I don't know. I put a call into the company that installed it, haven't heard back yet.

Do you think i'm barking up the wrong tree or could there be an issue with the boiler I'm not thinking of? I know there is no way I'm getting 900 CFM of air moving thru the shop as your calcs say.
Like you I don’t know what I don’t know
It is possible even likely it is a combination of things
Yes it is under insulated
Maybe the boiler is setup poorly and you are only getting 80 percent out of it
Hidden air leaks can move an astounding amount of air
In a large open area you may not notice cold spots
While we have all stuffed Fiberglas in gaps it is a very poor air seal so overlapping insulation could allow hidden air loss
You want an airtight tent with insulation
 
Gas creates a great deal of moisture but the exhaust shouldn’t really stink
I had to cut into my 24 year old exhaust pvc at work and it looks like it was never used inside
What are your water temps like
What is your floor temp like
Does the room temp ever overshoot the thermostat
Thoughts that may or may be relevant

return temps to the boiler I would think ought to be as low as possible to ensure condensing
I think the mod cons use return temps to decide what output should be unless you have a smart thermostat
Most of this should be details
 
From my research one of the big benefits to slab heat is you are only heating were needed 0'-8'. so it should be colder higher up. your not blasting super hot air that raises to the ceiling. the slabs 70 deg. its slowly heating.
maybe the big fans you have are hurting not helping.
 
I am not a radiant floor heat expert, but I do hope to use it in my next shop expansion. The research I have done says you can't run the pex down that deep. It will suck, you'll just heat the ground regardless of below slab insulation.

The pex is supposed to be closer to the top of the slab.

That could be your problem. All that heat is going right through your R10 slab insulation into all that rock you piled up.
...not here where it gets cold. The infloor heat, whether water or electric pads, are under the concrete. Last building I was part of the build, we had 8" concrete, and the heaters are under the concrete- otherwise, the strength of the concrete is compromised. Recovery time was less than a smaller building I was previously in which had radiant heat. The only people who benefit from radiant heat are the salesman and the gas dealer. I despise workin' under that shit. Heat goes "up"...
 








 
Back
Top