Heating 40x64 pole barn shop

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We have future plans to build an insulated 40x64x12 pole barn shop. The plan is to use scissor joists for the added interior height and to use radiant tube heaters. I have 2 Reznor 75k ( converted to 100k when new with factory kits). These were working warehouse take outs. Each came with 30' of tube. location will be Crossville Tn. Average winter lows in the 20's and winter highs in the 40's from what I read. Not currently residents, soon to be though. Will I need both of these units to be able to heat the shop or would one unit, maybe utilizing more sections of tube, 40-60" total be enough? Will have ceiling fans inside.

 

[BLUE72CAMARO]

I cant speak to the heaters as I have no experience with them but do you plan to keep this space heated all the time or ramp up and down as you are in there? Also do you need the extra head room to clear something you are putting in the building? If not all that extra space is just that much more air to try and heat for nothing.

 

[86turbodsl]

My advice - go 14' sidewalls and skip the scissor trusses. Flat ceiling, makes everything in your building easier to deal with and you don't have to heat that volume. 14' min ceiling can handle any lift or whatever you plan to do in there. That's the exact size of my building. I can do about anything at 14'.

 

[Snip]

This will be my retirement hobby shop, primarily metal work/machining and fabrication along with working on Harleys and cars/pick-ups. Will have a 4 post lift. Would only be heating when in use, heating shortly before going out there. This is still in the planning stage so 14' walls and traditional trusses is still an option. We were going with the 12' walls as to not overpower the house. Still looking at cost difference between the 2 options.
Still wondering if the one heater(100k) would be enough with the additional tube sections to heat the space or will I need both units?

 

[Poodlehead]

I'm assuming you have a welding table and what works really well for "localized" heating for me is using a Kerosun kerosene heater under the welding table. Most of the heat goes straight up, which heats the metal that radiates out...

 

[BKB]

I use 84k actual BTU to heat my 40x64x16 pole barn. Its forced hot air waste oil. I keep is 55' all the time and maybe 60' when working. It will get to 65' when its in the teens but would probably take 24 hrs to hit 70'. Im still missing 8 rolls of insulation for the walls and the 14x14 garage door leaks pretty bad.

 

[86turbodsl]

How big a heater you need depends on the heat losses. Mine doesn't need much at all. 4 windows, well insulated, about 2500 ft2 of space, waste oil boiler, floor heat.

 

[dcg9381]

Insulation?

 

[86turbodsl]

Not sure if you're asking me or OP, but mine is cellulose in walls and ceiling. About 15" in ceiling, about 5.5" in walls.

 

[dcg9381]

Asking the OP. Totally impossible to give advice on a 40x64 without knowing something about the insulation setup.

 

[86turbodsl]

Asking the OP. Totally impossible to give advice on a 40x64 without knowing something about the insulation setup.

Exactly.

 

[Snip]

Sorry, with as many posts I have read here you would think I would have included all of the proper info, oversight on my part. First off it looks like I am strongly looking at the 14' walls with conventional trusses (48" spacing) for several reasons. One of those is ease of insulation. Most likely am going to be using metal liner panels for the ceiling. Blown in insulation would stay level, Thinking R-30 in the ceiling. Posts are 6" with the girts 7 1/2" and stud walling between them so R-19 batts should work. Question here though, is it ok to just use 2x4 studs, flush with the front and allow the excess insulation to fan back out on the back side? Walls will (again, most likely ) be drywall.
Two or 3 insulated 3,0x3,0 windows, 1 10hx12w insulated panel door, gable end and 1 10x10 insulated panel door on the long side. I have worked on over the road semi's most of my life and will size my doors so on will never grace the inside during my retirement, lol
Heat will be natural gas, no plans currently to air condition as of right now. Maybe if my rich Nigerian relative dies and leaves me his lottery winnings that I can claim for a small processing fee we would look at A/C but not as of now

 

[86turbodsl]

Your insulation sounds similar to mine, you have about the same glass, and about the same doors i do. Same size building. I average about 6500 heating degree days here, south michigan. I don't know where you are in colorado, but punched up denver and checked heating degree days and it runs a little less than here. I heat my shop with a 100KBtu boiler. I am not running it hard. It was given to me. Short of running a manual-J on your building, nobody can tell you what exactly you need. The info i passed will get you in the ballpark to start looking at costs though.

 

[bobj49f2]

I live in SE Wisconsin. Our winters get below 0° for a week or more in a row in the winter. I have a 30'x50' pole building we just finished insulating. I was originally going to use wide roll insulation made for pole buildings but my son said to use regular house insulation. He recently did his boss's building so I told him to go ahead and do it. He lined the walls with horizontal 2x4s and laid the mat insulation in between the 2x4s.

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We used OSB plywood for the bottom 8' of the walls and steel panels for the upper walls and the ceiling with 13"+ blown into the ceiling.

When it came to heating the space my son and I had a disagreement of what to use. I wanted gas fired tube heat because I had it in my previous shop in the industrial park and I really like it. He wanted an oil burner because it would be "free" heat. My wife heard the word "free" and wanted to go that way. I right away saw many drawbacks to the oil heat. First, I didn't want an used unit, a new one was $5K. I also didn't want the hassle of storing and using waste oil. No matter what it's a mess and takes up a lot of room. I plan to use my shop 40+ a week for my business and I found reasons not to use an oil unit, the most important is the oil burner would burn about a gallon an hour, that's a lot of oil. There is nothing free about an oil burner unit.

I eventually bought a dual stage Re-Verber-Ray 65'/100K BTU unit thanks to the information I found on this board. I don't have access to NG so I have to run it on LPG.

The first thing I did when I decided on the heater is call the local distributor and with the manufacturer they were able to size out a unit to use in my building. I sent them a drawing of the building, the number and sizes of the windows and doors and the insulation installed. They were able to work up a heat loss calculation and spec out the size unit I needed. This is the best way to go find out the size you need. Asking a group on a discussion board, while very helpful, isn't going give the specific information you need. My first shop with the infra red tube heaters was 50'x50' and had two unit, I usually only used one. I would only fire up the second unit if it got really cold out and once in a while to make sure it worked, maybe a total of three times a year. That building was built as a two unit building with a wall cutting the building in half. I bought the building as one big unit without a center wall.

I have been running my tube heater for about three weeks now and it works great. I installed it myself. The major drawback of a tube heater is it does take additional time to initially heat the building so I go in about 15 minutes early and bump the heat up.

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I also have an electronic thermostat that I have set in four different time intervals. I set all my temp to 45°. I have a "wake", "leave", "return" and "sleep" settings. My normal settings are "wake" 65°, set to start 15 minutes before I plan to work in my shop in the morning. "Leave" is set at 45°, set at the time I plan to work in my shop. I set this lower because many times I don't go in my shop, I go to a customer's job site for the day and I don't want to heat the shop if I'm not there. Return I have set 45°, set at the time I normally leave my shop for the day. I don't have to worry about forgetting to set the temp back when I leave. "Sleep", set at 45° at five hours after I normally leave my shop. Many times I work late, past my normal departure time so when the "leave" temp starts to drop I'll goose the temp up but it will drop again later in the night.

 

[astroracer]

Do you have to heat the WHOLE building? My shop is 30 x 74 but I only heat a small portion, 26 x 30. That is where all of my machine tools are.
One thing you will learn real fast is spot heating creates a lot of condensation. Going from 20 to 60 degrees will have all of your tools covered with it. All of them.... Every time. You will want to look into keeping a working area warm all winter long. I keep my shop at 50 or so all winter long. Keeps the moisture out and is still very comfortable to work in for a few hours. If I am going to be out there all day I will kick it to 60 or 62. Shirt sleeve weather in my neck of the woods.
I am using an old forced air gas furnace and it heats my shop for less then 50 bucks a month, even in January and February...
Mark

 

[bobj49f2]

I've worked mostly in shops with the forced air units, it seems either you're roasting or freezing. I've been in shops where the only way to stay warm on really cold days is to work directly in front of the heaters. I didn't know anything about the tube heaters until I visited a guy who was going to install a unit in his garage. He told me they were more energy efficient than the forced air units and provided a steady heat. When I bought my industrial park shop I had the building upgrade their standard forced air units with the tube heaters. From the first day I used the heat I loved them. My heat bill was so low when I told people how much I paid they had a hard time believing me. In fact the gas company wouldn't believe me either. I had to go around with them for the first two years because they put a minimum usage charge on the unit I never used. They told me according to their calculations the building of the size of my building had to use a certain amount of energy to heat. This discussion went on for the first two years I was in the building. I finally got it through their heads I was only using one heater.

The units are more expensive but I've read they will pay back in 2 years.

The nicest thing about the radiant heat is it heats the objects in the room. The floor is almost as warm as if I had floor heat. Also, I can open the overhead doors for short periods of time and not lose heat. With a forced air system the building is pressurized and the heater is forced out when you open the doors. They do take a bit longer to heat the place but it's not too bad.

As you can tell, I'm a big fan of radiant tube heaters.

 

[Snip]

bobj49f2,
I have worked in shops with forced air, radiant floor and overhead radiant tube heat and would have to say that the overhead radiant heat is my favorite also. Very glad to hear it is as efficient to run as I have heard. Thank you for your input. I was very lucky to score the two Reznor 100k units I did off of C/L. Nice bright shop you have there.

86turbodsl
It does indeed sound like we are on the same page as far as shop size goes. Glad to hear you can easily heat it with 100k. While we do live in the Denver area now we will be retiring to the Crossville Tn area next year. This is where I will be building the shop. A little milder winter than you are in, Average winter low's in the mid/upper 20's with winter highs in the 40's. With a good insulation package I feeling confident that I should be able to get by with the one 100k unit? That amount of BTU's seem to be working for you and bobj49f2 in a more northern climate.

astroracer,
Most likely I will be heating the entire space. Thank you for the info on condensation. Coming from the Denver area with almost no humidity to a place with humidity, it is something to consider. I keep that in mind and will try keeping some heat in the building and doing somewhat less of a rise when working out there.

 

[bobj49f2]

I like the gas fired tube radiant heat over the type with the grid that glows. I think those are made for areas where there can be a drastic change in temperatures like large door entrances and loading docks. I worked in place that had the glowing type and there was an old guy who would crank the heat up to 80°. It was like working under a hot dog roaster. He was an old timer and whenever someone would turn the heat down to a more comfortable working temperature the old guy would crank it back up. One of the many reasons I didn't stay employed at that place. I personally like working in about 65-68°.

 

[aventino68]

I like the gas fired tube radiant heat over the type with the grid that glows. I think those are made for areas where there can be a drastic change in temperatures like large door entrances and loading docks. I worked in place that had the glowing type and there was an old guy who would crank the heat up to 80°. It was like working under a hot dog roaster. He was an old timer and whenever someone would turn the heat down to a more comfortable working temperature the old guy would crank it back up. One of the many reasons I didn't stay employed at that place. I personally like working in about 65-68°.

Sorry to Hijack, I'm in similar climate Ontario, building an identical size garage similar insulation (I think) and have to run LPG from a tank as well since there's no natural gas supply out here. Can you give me an idea how much gas you think you'll go through in a typical year. Seems like your heater is also my best option.

 

[bobj49f2]

Not sure yet how much gas I'll be using. I just had the tank installed and have only heated my shop a few days a week so far. I am getting some big jobs in the shop this week and will be busy for at least six months. In my business I do about 50% of my work in my shop, doing 40+ hour weeks, and 50% installing on customer job sites. I do know in my old shop with the tube heat I would always amazed people who had similar sized buildings on the cost to heat the building. On the coldest months my utility bill, including electricity, was around $350. The utility company supplied both gas and electricity. The building was also very well insulated, 6" walls and 12"+ in the ceiling.