Another opinion thread. heating a 30x40. And insulation question.

[tuner4life]

Alright, I know that there a million "what's best for me" threads out there, but I'm going to ask anyways.

I am going to be acquiring a property with a 30x40 pole barn. It has 12' or 14' doors on one end, so I'm assuming 14' or 16' ceilings (estimating, might be taller). Currently the only source of heat is a small wood burner. We haven't moved yet, so I don't know how effective it is, but I do work on cars quite a lot and am not a huge fan of the fumes/fire mix, and I have no desire to start chopping wood, so it's really not the best option for me.

There is a nat-gas line run into the building, but it is not hooked up to anything currently.

The 2 options I am comparing is either a hanging "box" style heater, or a hanging tube-style radiant heater. Now here are all of the dumb questions:

1) I'm assuming that efficiency-wise, the radiant tube heater will be cheaper to run, but which would heat more effectively? Faster? I do plan to leave it heated at least minimally at all times in the winter.

2) Since this building has taller ceilings, which heater is better for having heat reach floor level? Actually heating the concrete? Would I need fans to blow heat down?

3) If it was yours what would you pick and why? Any information I'm missing to make a more informed decision? It seems that from what I have read, a single tube radiant heater running lengthwise down the middle of the ceiling may be the best option, but will that heat the sides too, or only in the middle? I have no experience with that style heater.



Also, I want to eventually insulate the building as well as possible. It currently has what looks to be foam board against the walls. I can't tell how thick it is, Is it effective at all? Should I just get rid of it and start over? Leave it in and add something over it?

Sorry for the dumb questions. I'm new to having to heat this large of a space and am trying to do my homework.

 

[earthworks]

Foam board is one of the best insulators when properly installed (no gaps). definitely leave it in place. post some pics and then we can comment on how to proceed in the easiest most cost effective fashion.

heat travels in three ways (same as electricity). Convection (air or liquid flowing), conduction (travelling through a solid substance) and radiation(UV or infrared rays mostly).
as for radiant tubes getting the heat to the floor.... they radiate the heat, which means it produces rays of heat that travel straight (unless reflected) until they hit a surface and heat it. I will be well suited to heat the floors and any other surface it can "see" no matter the height.
A forced air heater unit will work via convection... heating the air and blowing it around. If you attempt to heat the air, you will need more btu as your square footage needs to be multiplied by your ceiling height to determine the entire volume of space that needs to be heated.

very different heats, radiant is very area specific, and convection should be more of an all room heat.

 

[tuner4life]

Thanks for the info! We should be closing within the next couple of weeks and will take possession of the pole barn immediately. I will post more pictures/info/measurements when I can.

 

[tuner4life]

Alright, we got possession of the barn yesterday! Going to start a new thread for that in the gallery, but here is a picture of the inside. It's 30'x40'x15' with (2) 14' doors on the end. The interior walls are very well covered with 1.5" foam panels.






So now that you guys can see what I am working with, what would you recommend for extra insulation? Will the foam be enough? Or would I benefit from something extra? I plan to finish the interior walls in OSB eventually and add a loft over the rear third of the shop.

Also, would a radiant tube heater be effective in heating this building? Or would I be better off with a hanging box style heater?

Thanks in advance!

 

[Highbeam]

It's a death trap now with all that exposed foam. Looks like a nice blaze king woodstove. Those puppies cost over 3000$ new.

Radiant tubes are effective, so are hanging heaters. Both are fairly cheap, I would keep the woodstove and add a radiant tube.

 

[CNGsaves]

Wowsa . . . +1 that open walls are just a tipped over propane heater away from giant black smoke nasty fire !! Be VERY CAREFUL in there until all that is covered.

Great looking building though . . . . awesome possibilities.

I'd develop an overall gameplan for your improvements. Start with ceiling lighting and decide if adequate, or if you'll improve. Also do any rough electrical upgrades like hanging electric reels, wiring for lift, hanging heater, etc. Can't tell if ceiling is sheeted with OSB or what. I'd make sure those seams are taped/sealed so you have an airtight upper envelope. Paint that ceiling bright white to reflect as much light as possible.

Then, get your ceiling insulation at high level from R-40 to R-60. Blown paper cellulose would be affordable but efficient/safe.

For walls, I'd recommend you stick-build out for deeper walls & do all your rough electrical improvements for outlets near benches, outdoor lighting, 240v for compressor, 240v for welder, etc. Then follow what other GJer did and install wood horizontal framing and vapor barrier to hold in blown paper cellulose insulation that would supplement insulation that's there already. Sheeting for walls could be "good side out" of OSB that's edge caulked while installing to provide air envelope. Then paint all OSB walls bright color. Finally cover lower portion with corrugated steel over where the wood burner stove is located. Might look good to go all around shop with lower portion corrugated steel up to chair-rail height, capped with wood molding.

With NG line ready for building, I'd surface mount black pipe steel up to location for hanging NG heater. Likely a 60K to 75K Btu heater would do good job, but do loss calculations based on your insulation, doors, sq ft, etc. Wood burner would keep building as warm, as you'd like chopping wood !!

/ {.02 idea on how I'd do it !!}

 

[jpeace3]

check out the heat exchanger blowers from northern hydraulic. They mount in the stove pipe a foot or two above the stove and capture the heat going out the stack. A fan in the back blows the heated into the room. Works great. Also in my shop ( 40x60 ) I use the wood heater and also have three chicken house brooders hanging from the ceiling. Mine are set up for Propane but can be adapted to natural gas. Mine are older and have pilot lights but the newer ones have electronic ignition. Doesn't take long to heat up a shop.

 

[rabies]

that woudl be the ideal perfect shop. welding corner. parking van and jeep. and work working other side...luuucky. i would stick with wood burning though. cheaper but more work to keep going than just a gas furnace. depends on your wallet. or mayyybe pex flooring heating?

 

[rancherbill]

That's a great looking shop.

It looks like it's 3/4 finished. This is normal, they all seem to turn into multi -week, month, year, decade projects.

It looks like he was using foam 'cutoffs' from some where. Could you post a pic or details of the joints between pieces and also to wood members?

It's an important step in a heating project.

 

[classic boost]

nice garage!
just a note: check with your ins company to see if a wood burner in the garage is ok with them. mine said no-go. don't want any surprises at the worst time.

 

[tuner4life]

Thanks for the ideas!

The wood burner is definitely not going to stay. There is some metal between it and the wall that protects the foam, but I still don't trust it.. Plus I don't feel like chopping wood the rest of my life, I'd rather be working on the cars . It will be replaced with something NG powered.

As for the insulation, I will take better pictures the next time I am there. I am not sure about the ceiling (I will find out), but the foam on the walls is 1.5" thick and it all fits very tightly, there are virtually no gaps at any of the seams. I feel like I could frame 2x4 walls in front of the foam and insulate it in a standard fashion and it would probably be fine. I want to do the best insulation job I can but don't need to go broke doing it. I will research the blown in option as well. Walls will for sure be OSB painted white, Ceiling would ideally be corrugated metal. But White OSB would work too.

 

[tuner4life]

Alright, now that I'm actually having some time to mess with the barn, I'm going to revisit this..

The foam is about 3" thick and seems to be the only thing between the siding and the interior. It is tight and there aren't really any drafts to speak of, but it doesn't seem like it works all that well.

I do eventually want to finish the walls with OSB and add a loft, would it be better to just add the OSB right over the foam? Or would I benefit from framing 2x4 walls inside of the foam and insulating that as well?

Also thinking a vapor barrier (plastic sheet) would be a good idea.. where in the mix should I put that?

Sorry if all this is noobish.. I can do prettymuch anything with a car, but construction is all new to me..

 

[Slowgsr]

Didn't read the comments, based on what I did and if I were to do it again here's what I suggest. I have a very similar building.

Fur out the walls - 2x6. Rough in your electrical, etc. Go r19 roxul in the walls.
Then 6mil poly, take time to get it sealed. Taped/acoustic sealant etc.

Ceiling is fill the void with either r14 or r19 roxul depending on if it's 4 or 6" truss.
Then blow in cellulouse to r50. Make sure there's no roof leaks!

That material on the ceiling pull it down, the shop should be fire rated. I'm not a fan of combustables on the walls/ceiling.

5/8 type x everywhere. 3 coats finish taped.

Then do 2 radiant heaters at each side on a 45 up in the corner. I'd do x2 45k btu.

The box heaters blow dust and dirt everywhere, it's a pain.

The above is what I did in my space, and it's great. Make sure your weather stripping is tight around doors etc.

 

[tuner4life]

Thanks for the input! Those are the kind of ideas and info I am looking for.

 

[theoldwizard1]

Or would I benefit from framing 2x4 walls inside of the foam and insulating that as well?

More insulation is ALWAYS better, if you have the money and space.

Super insulated buildings (like the ski slope in Dubai) have an outer insulated wall, a large air gap (3-5 meters ?) and an inner insulated wall. A vacuum is a very good insulator (Thermos bottle), but so is "dead" air.

"You pay for insulation once, you pay for energy to heat and/or cool your space every time you turn on your HVAC system."

 

[theoldwizard1]

Fur out the walls - 2x6. Rough in your electrical, etc. Go r19 roxul in the walls.

Rock/mineral "wool" (ROXUL® | Fire and Soundproofing Insulation) is expensive. It is a great sound deadener and may give better wire protection, but I don't think it can compare on "cost per inch" thermal resistance to other medium.

Cellulose is typically the cheapest "cost per inch". "Wet" installation is easy and definitely DIY. There is nearly ZERO waste. Some people say cellulose compacts over time.

 

[DC73]

Also thinking a vapor barrier (plastic sheet) would be a good idea.. where in the mix should I put that?

Recommended reading:

http://www.greenbuildingadvisor.com/blogs/dept/musings/do-i-need-vapor-retarder

http://www.greenbuildingadvisor.com/blogs/dept/musings/vapor-retarders-and-vapor-barriers

http://www.buildingscience.com/documents/digests/bsd-106-understanding-vapor-barriers/

If you don't read anything else, read this last paragraph of the 1st GBA article linked above:

• Most buildings don’t need polyethylene (plastic) anywhere, except directly under a concrete slab or on a crawl space floor.
• The main reason to install an interior vapor retarder is to keep a building inspector happy.
• If a building inspector wants you to install a layer of interior polyethylene on a wall or ceiling, see if you can convince the inspector to accept a layer of vapor-retarder paint or a “smart” retarder (for example, MemBrain or Intello Plus) instead.
• Although most walls and ceilings don’t need an interior vapor barrier, it’s always a good idea to include an interior air barrier. Air leakage is far more likely to lead to problems than vapor diffusion.

Another pertinent comment from the 2nd GBA article linked above: "Unless you’re building in Canada, Alaska, or somewhere close to the Canadian border, you don’t want interior polyethylene or vinyl wallpaper — especially in an air-conditioned house."


DC

 

[bzinsky]

If you attempt to heat the air, you will need more btu as your square footage needs to be multiplied by your ceiling height to determine the entire volume of space that needs to be heated.

the btu's it takes to heat a space is going to be the pretty much the same no matter what heating system you use.

Heat is energy, all that really matters is the energy you produce vs the energy that leaves the space.

For example, why is radiant floor heat efficient, not because it heats the floor, it's because water temps can be lower with such a massive heating surface area. Lower water temps means that your heat exchanger can absorb more heat from the flame. The flame is produced, it comes in contact with the heat exchanger that transfers the heat of the flame to the water, and the colder the water, the more heat it will absorb as it passes through, thus less heat goes out your exhaust. Less heat going out the exhaust means more heat inside. Energy in energy out.

If you were wondering why new efficient water heaters can have PVC exhaust...it's because there isn't much heat coming out of the exhaust, it's all being absorbed by the water.