Shop Heating

[Rutabagared]

Cubsfan,

Here is an online BTU calculator. It should put in you the ballpark.

The vapor barrier should go between the insulation and the interior space for northern climates (opposite in the southern climates). If you buy faced insulation, the paper facing serves as the vapor barrier. If not, you can use 6ml poly sheet available at home centers and hardware stores. Apply it over the insulation by stapling to the studs.

Yes. You will need separate circuits for each heater.

Joe

[Lawrence Brown]

...

The vapor barrier should go between the insulation and the interior space for northern climates (opposite in the southern climates)....

Joe

Wait. Opposite in the southern climates? Are you talking about south of the equator, or closer to it in the northern hemisphere?

Either way, you have me curious. Why would it go on the outside further south (assuming you mean the northern hemisphere). Is it because it's generally drier and the humidity would be expected to be higher on the inside?

[Rutabagared]

Mechanologist,

No. "North" and "South" were meant to distinguish between cold (Pennsylvania - heat the interior) and warm (Arizona - cool the interior) climates.

Vapor barriers are intended to prevent the transmittance of water vapor (in warm air) into the wall cavity where contact with cooler air/surfaces results in condensation. Therefore, vapor barriers always go on the "warm" side of the wall - where the moisture is located. In cold climates the vapor barrier is placed between the heated interior and the wall cavity. In warm climates it's placed between the "heated" exterior and the wall cavity.

Joe

[Lawrence Brown]

Aha! Thanks for the clarification. Makes sense now.

[Vic]

Hey Mech...here's a link to give you more information and a map for VDR placement. http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11810

Btw, this site is a pretty good site for advise on most energy efficiency subjects. I have found a couple things they get wrong, but all in all, a good site.

[CubsFan]

Thanks for all the help everyone. I've got a week off in a couple of weeks, so doing this will be a couple of days of it.

Another question: How important is drywall? Here's my situation. On one wall of my garage, a previous owner put up a bunch of plywood over the studs. I was planning to take it down, put in the insulation, and then put the plywood back up. Will that be suitable, or do I really need drywall? Also, in another part of my shop I have pegboard hung up that I really like. I know it's basically full of holes, but is that a suitable covering for the insulation, or will that really screw me having so many holes there.

Thanks for the help!

[Vic]

The plywood is OK from an energy stand point, IF you caulk/seal ALL the joints. It won't be to code, to my knowledge. If you want to use the pegboard, finish out the wall and use cleats to give yourself the space needed behind the pegboard.

[Beechwood Chip]

My guess is that drywall is fire retardant, so some codes require it. Also, it's less expensive than plywood. Plywood is not fire retardant, but it's easier to screw/nail/glue stuff to it for storage. I'd use plywood if I was allowed to, if I could afford it, and if I wasn't worried about fire. OSB might be a less expensive (but uglier) alternative to plywood.

[Rutabagared]

Cubsfan,

I'm a fan of drywall. As Chip stated, drywall is fire retardant. I don't think plywood/OSB complies with building codes, but check to be sure. If it's not code compliant and, God forbid, you have a fire; it will likely affect your insurance claim.

You can install the drywall and have the seams remain unfinished relatively inexpensively. I'd also research the cost of having the drywall installed professionally. The price may surprise you (pleasantly) and it will save your back.

You can also reinstall the plywood and install drywall on top of that. This will facilitate future wall storage. Good luck and enjoy the process whatever you decide.

Joe

[Vic]

The drywall will need to be "fire taped", which is just the initial layer of paper and mud.

Cubsfan,

I'm a fan of drywall. As Chip stated, drywall is fire retardant. I don't think plywood/OSB complies with building codes, but check to be sure. If it's not code compliant and, God forbid, you have a fire; it will likely affect your insurance claim.

You can install the drywall and have the seams remain unfinished relatively inexpensively. I'd also research the cost of having the drywall installed professionally. The price may surprise you (pleasantly) and it will save your back.

You can also reinstall the plywood and install drywall on top of that. This will facilitate future wall storage. Good luck and enjoy the process whatever you decide.

Joe

[CubsFan]

I'm hoping this isn't a dumb question, but what about leaving the insulation exposed? I realize I won't get the benefit of the fire block of the drywall, and nor will I have extra fuel for the fire. I assume one downside is that the effectiveness of the insulation will decline, but any others?

[jimmykx250]

Just my 2 cents here but I just bought a gas fired furnace late last winter because i couldent take another year smelling the kerosene! I honestly believe unless you go with a pretty substantial electric job you wont be comfortable. The small gas fired units are sooo cheap especially if you shop them on craigs list or do like i did and call local heating and air suppliers and ask for the dented and brused inventory list, they all have them and they cant sell them at full price and they usually come with the full warranty. As for gas pipe that's another thing alltogether. If you dont feel comfortable running the gas pipe yourself then the labor number is something to consider. I can only say man i love my forced air garage blaster it makes working in the garage in the winter fun again!!! Just my 2 cents though.

[Rutabagared]

I'm hoping this isn't a dumb question, but what about leaving the insulation exposed? I realize I won't get the benefit of the fire block of the drywall, and nor will I have extra fuel for the fire. I assume one downside is that the effectiveness of the insulation will decline, but any others?

CubsFan,

You sure can! The effectiveness of the insulation will remain the same. You can always add wall coverings later.

Joe

[PaulMarcel]

I don't think the insulation will work nearly as well if it isn't covered. Air flow through insulation makes it worthless, IIRC. The "uncovered" stuff in the attic is still effective because there is generally little to no airflow through the insulation (over, yes, not through).

For heating, consider a pellet stove. I've heard that people really like those, doesn't take much, and it is very effective. Portable, too. I'm in AZ. Absolutely no need for a heat source in my garage. Even in the deep of winter (3 hours in the early morning of Jan 5) when it's 45º in my shop, I'm toasty from all the saved heat when it's, what, 108º today?!? good grief... and I have 5 sheets of ply to rip and band. I'm killing time of the "avoidance behavior" type.

[jab73180]

i did a search on gas heaters on craigslist and come up with one from a camper. why wouldnt that work in a small shop? let me know what you guys think.

[Vic]

I'm hoping this isn't a dumb question, but what about leaving the insulation exposed? I realize I won't get the benefit of the fire block of the drywall, and nor will I have extra fuel for the fire. I assume one downside is that the effectiveness of the insulation will decline, but any others?

The exposed insulation is huge. But, if you don't mind it not working like it should. It will still be better than nothing, though.

[Rutabagared]

CubsFan,

You won't get significant air flow through unless the outside wall has gaps, etc. The vapor barrier will prevent airflow from the inside. I worked with exposed insulation last winter and didn't notice much difference at all once I had blue board and plaster installed.

Joe

[Vic]

I don't think the insulation will work nearly as well if it isn't covered. Air flow through insulation makes it worthless, IIRC. The "uncovered" stuff in the attic is still effective because there is generally little to no airflow through the insulation (over, yes, not through).

For heating, consider a pellet stove. I've heard that people really like those, doesn't take much, and it is very effective. Portable, too. I'm in AZ. Absolutely no need for a heat source in my garage. Even in the deep of winter (3 hours in the early morning of Jan 5) when it's 45º in my shop, I'm toasty from all the saved heat when it's, what, 108º today?!? good grief... and I have 5 sheets of ply to rip and band. I'm killing time of the "avoidance behavior" type.

I have had clients that had the prerequisite R38 blown into their attics using loose fill fiberglass and had horrible heating problems. We live in a rather windy area and it is nothing to have fiberglass insulation become almost ineffective. Another thing is a few of the companies will "fluff". Be sure to always demand the bags and the bag count for your square footage. What I have had success with in cases like these is to blow a minimum of 4" of loose fill cellulose over the loose fill fiberglass. All of a sudden the air infiltration is nearly stopped and the insulation becomes effective. The same problem happens in the crawl spaces. It's why I like the manufactured home approach better for crawlspace insulation. They use a "bellypan" and the insulation goes between that air barrier and the floor. Because the insulation does not touch the floor, you are effectively heating more space. But, it does work better.

[Beechwood Chip]

I've been told that making a space energy efficient actually requires three things:

• Keep rain, snow, etc out - roof, siding, eaves, gutters, foundation
• Keep air from moving in and out, except where and when you want it to - house-wrap, drywall and tape
• Keep heat (radiation) from moving in and out, except where you want it - insulation, double pane windows, storm doors

Often these three barriers are adjacent, but sometimes they aren't. For example, a basement or crawlspace might have the air/moisture barrier on the floor and walls, but the insulation on the ceiling (floor of the living space). Or an attic would have the air and heat barrier on the ceiling of the living space, but the

So, when deciding whether to cover the insulation or not, you have to think about whether you will have an effective air barrier. The insulation stops heat, not air (or water). The siding stops water, but not air or heat. If you have house wrap under the siding, or some other air barrier, then you can leave the insulation exposed, I think.

[Vic]

I've been told that making a space energy efficient actually requires three things:

• Keep rain, snow, etc out - roof, siding, eaves, gutters, foundation
• Keep air from moving in and out, except where and when you want it to - house-wrap, drywall and tape
• Keep heat (radiation) from moving in and out, except where you want it - insulation, double pane windows, storm doors

Often these three barriers are adjacent, but sometimes they aren't. For example, a basement or crawlspace might have the air/moisture barrier on the floor and walls, but the insulation on the ceiling (floor of the living space). Or an attic would have the air and heat barrier on the ceiling of the living space, but the

So, when deciding whether to cover the insulation or not, you have to think about whether you will have an effective air barrier. The insulation stops heat, not air (or water). The siding stops water, but not air or heat. If you have house wrap under the siding, or some other air barrier, then you can leave the insulation exposed, I think.

No, because if the insulation is exposed and not in an airtight environment, the interior air will migrate through it quite easily to the outside wall and be lost though conduction. The simple basics to heat transfer are heat moves to cold. There are three ways heat moves to cold. Convection, Conduction and Radiation. Moisture travels most forcefully with heat, but CAN move in the opposite direction if there is enough moisture...cause moisture moves from more to less and usually that is in alignment with heat, but not always. Like I said, you CAN leave the insulation exposed and it will be somewhat effective, but no where near as effective as if you created a good air barrier. Craft backed will help, but is not an very effective air barrier.

[sdkidaho]

Here is an online BTU calculator.

The vapor barrier should go between the insulation and the interior space for northern climates (opposite in the southern climates).

You will need separate circuits for each heater.

Good info - thanks!

In cold climates the vapor barrier is placed between the heated interior and the wall cavity. In warm climates it's placed between the "heated" exterior and the wall cavity.

So what do you do if you have both? I mean, I'm not in Arizona or anything, but in the summer we can hit 100 degrees at times. Would you put up vapor barrier on both sides for that or just choose one and do that?

[Vic]

Good info - thanks!

So what do you do if you have both? I mean, I'm not in Arizona or anything, but in the summer we can hit 100 degrees at times. Would you put up vapor barrier on both sides for that or just choose one and do that?

Check out the link I referenced. It has a map of the US with recommendations.

[leebo]

I read the other day about a guy who just turns his window air conditioners around backwards and uses them to heat in the winter. I don't know how well it really works but he said he has done it for 20 years. I got a kick out of that.

Honestly.....This is nothing more than a "heat pump". It's taking the cold air out of the room and putting it outside. Sometime in the summer go and stand behind a window unit outside....the air is hot as heck. The main way these work is by transferring the cold air to one side, and displacing the hot air somewhere else. Is this a practical way of heating the whole house...not really. Does it work...ya.

Now.... If your walls are nothing more than cinder block at this point I would skip the fiberglass insulation. You would have to build a fake wall of 2x4's to put the fiberglass into. Then it would be best to cover the insulation with some sort of "hard" structure. Even plywood would work in this case. In time the insulation will become lose and start to fall. Over the years of woodworking it will get clogged with dust and such, and will make a HUGE mess all over your finished projects. Spend a few bucks here if you go this route and cover it.

However; I'd go a different route all together. I would use Insulated Sheathing. This is like the pink or blue insulation that builders use on the outside of this house. To do this you'll have to nail some 1x2 boards up about every 4 feet or so all the way around the wall (if it's cinder block). Then just cut the insulation if your ceilings are to high and screw the insulation into the 1x2's If your ceilings are higher than 8' then you may need to add more 1x2 or cut the insulation to make it work. This stuff runs about $8 for a 8'x4' board and has an r value of around an R5. Just make sure to tape up all your seams when you're done. Really no need to cover this up once you're done as well. It really all depends on what your garage is constructed of and what's built in terms of walls.

To do the door I would skip the "kit" they sell. Buy some double sided tape, and some foil insulation. Total of this should be around $20 or so...and just as effective as the kits'.

As for your heater. Whatever unit you purchase...make sure they qualify for the government tax rebate. Keep this in mind when you're purchasing the insulation as well. Keep all receipts. You can mark up to 30% of the work off on your tax return. I'm not sure how your house is and your garage...but this is something to keep in mind when you're making your finial purchase.

http://www.energystar.gov/index.cfm?c=tax_credits.tx_index

Lastly....With you having natural gas you may want to look into programs your gas company has in place for energy upgrades. I've had my entire attic insulated with 15 bags of blown in insulation and the basement of my house spray foamed professedly for under $50 thanks to programs from the gas company in Ohio. Look around and give them a call....it may not apply to your detached garage...but it may help ya out in your house.

Here's a copy of a program in Ohio for ya to look over.

http://www.columbiagasohio.com/en/about-us/news-room/columbia-ohio-news/09-06-11/columbia_gas_names_partner_for_energy_efficiency_programs.aspx

[Vic]

The programs that Leebo mentioned is what I do on the electric side. If you use the rigid foam, go with the blue board. It's just over R6 per inch. Unless you have a creative accountant, your shop space won't qualify for any of the tax credits on residential housing and, although I would check, probably won't qualify for the residential program he used for home energy upgrades.

[davidrn]

I have two types of heat in my shop, both direct vent. I didn't want to get into building a chimney, so went with a pellet stove and two direct vent propane gas space heaters. This gives me a little more than 100K BTU's, but I live in North Central Msssachusetts, on the New Hampshire border, so its cold in the winter. I have a 24 x 40' 2 story pole barn, with R19 throughout. The choices I made were based on price and least amount of work. The pellet stove was 300$, about 5 years ago, and the 2 Empire type heaters were 150$ and 200$ each, both gas heaters had fans and the intake/exhaust pipes.

These have proven to be great choices, I bought a couple of tons of pellets a few years ago,I have two gas tanks, a 100lb and 40lb, I usually only heat starting on friday in the morning, until Sunday when I quit for the work week.

As far as interior walls, I went with horizontal,shiplap pine,its easy to attach cabinets to the walls, amd hang tools, etc.