Insulating/cooling garage

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  #1  
Old 01-28-13, 09:29 AM
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Insulating/cooling garage

I have a standard size two car garage attached to my house. I want to insulate the prebuilt, sheet rock walls. I've read a few things that say you can cut holes in the top between each stud and blow in cellulose insulation. My question is what's better, the blown in stuff or the foam, and how much is the cost different? I also plan on insulating the garage door and attic.

After I've completed all of the insulation aspects I want to install some type of A/C unit, ideally I'd like to be able to cool it down to around 60 degrees, but when it's 100 outside I don't know if a 40 degree difference would be possible.

The idea will be to store flowers in it a few days per week, that's why the low temp is desired. I'd like to stay as reasonably priced as possible though, since eventually I'd reach diminishing returns and if a few degrees difference would be a significant cost I'd have to weigh that out.

The garage is 18'x19'x8' totaling approximately 3000 cubic feet.
 
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  #2  
Old 01-28-13, 09:56 AM
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Insulating Garage

Hey, I've been battling with the same issue where I live, and my garage is about the same size as yours.

I added foam sheets to the garage door, tightened the spring by 3/4 of a turn and the motor handles the whole thing just fine. The added foam sheets gave me a 10 degree rise in temps - during this winter. All in all I've noticed a huge difference with my heating bill too. Saved $70 this month.

I've been experimenting with Great Stuff (Gaps and Cracks) foam sealant. I can get it for around $3 a can, and with one wall being 12' x 19'. I've managed to drill holes between the studs at 2ft intervals (six per stud).

I got a quote from a company of $600 for foam insulation for that one wall - which I thought was a little high. That's why I went with 'Gaps and Cracks'.

This way, I can go at my own pace, a little every couple of weeks, or whatever works for you.

The total cost for me was: 19' wide wall, 12' high = 14.25 sections of 16" (stud width). Each can of Gaps and Cracks fills 2' high per stud section. That equals 6 cans per section (6 * 2' high = 12' high). With 15 (I can't round down, or I'd leave a quarter section with no insulation) sections multiplied by 6 cans, that equals 90 cans in total. I get the cans for $3 each, = total cost of $270.

As a tip, I learned to do one can per section every two days. That way the foam can set (it's a slow setup foam) and I spend about 10 mins each day for six days filling my walls.

I hope that helps.

If you'd like to see pics of the garage door with foam insulation sheets, I can post on here for you. Just ask.
 
  #3  
Old 01-28-13, 09:58 AM
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There are heat loss programs (load calculations) that will allow you to calculate different options and decide on the size of ac unit needed. However, most recommended solutions are based upon 78 or there about. I don't use the load calc software so maybe they can include that as an option.

One thought would be to use a removable door assembly to cover each opening with very thick panels. The normal insulating for a garage door would doubtfully be enough.

Are your walls 2 x 4's or 2 x 6's? Foam will be more than twice the cost of blown in cellulose, but if you have 2 x 4's the extra insulation value of the foam might be a trade off.

Some of the ac pros will have to advise on how much is needed and the size ac unit.

Bud
 
  #4  
Old 01-28-13, 10:11 AM
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Bloop, you used just the regular stiff sheets of insulating foam on the door? Post a picture. Surely there has to be a foam insulation you can buy and bulk and rent the dispensing equipment, is there not? Seems like using 90 cans of insulation there might be a cheaper option. Although I know it might be somewhat of a monopoly on the bulk stuff so the DIYer can't access it.

Bud, the walls are 2x4's. According to the BTU calculator for 350 sq ft I'd need around 9000. I can buy window/through wall units all the way up to 25,000 it looks like. If I oversize it should get me low enough temps, I just would need to know by how much. I don't have any windows in my garage so I'll just cut a hole though the wall and frame in the unit at whatever height would be best. They probably can't run sideways, can they? Where I could mount it in the attic pointing down and get attic fans to remove the exhaust heat?
 
  #5  
Old 01-28-13, 11:43 AM
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Regular Stiff Sheets - yes.

Yeah, I used the stiff sheets you get at the DIY store - Lowes I think. It's called Polyshield, has an R value of 4 per inch, and has foil on it to reflect more heat into the room.

It comes in 8' tall, by 4' wide sheets. I had them cut it at the store, and used 4 of them on each section of my garage door, with the door being exactly 16' wide, it fit perfectly. They weigh next to nothing, but to rebalance my door I just turned it 3/4 of a turn more - and it works perfectly.

Here's some pics:

Polyshield - http://i.imgur.com/zTa8YdC.jpg
R Values - http://i.imgur.com/HQg5u3t.jpg
Right side of door - http://i.imgur.com/8ihCS85.jpg
Left side of door - http://i.imgur.com/SOSc05h.jpg
Full Door - http://i.imgur.com/NbkMI89.jpg

It was probably one of the cheapest mods I've done. Each sheet cost around $10, and each sheet covered an entire 16' section of the door. Four sheets were used in all, and the temperature difference has been significant. If I'm working in the garage, my body heat alone makes it warm in there in around 10 minutes.

I stuck the sheets to the door with liquid nails. That set in around 15 mins, and I'd taped (with scotch tape) the edgest (top and bottom) to the door to hold it in place until the liquid nails set. Then I removed the scotch tape, with no tears or residue left on the foil.

I only just filled my walls with foam, so I can't really give an extended review of those results yet.

Hope this helps.
 

Last edited by BloopBloop; 01-28-13 at 11:59 AM.
  #6  
Old 01-28-13, 11:52 AM
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Sorry, I forgot to comment on "Surely there has to be a foam insulation you can buy and bulk and rent the dispensing equipment, is there not? Seems like using 90 cans of insulation there might be a cheaper option. Although I know it might be somewhat of a monopoly on the bulk stuff so the DIYer can't access it."

Yeah, I looked into the kits you can get online. I couldn't find any that would have been under $400 for the kit; and they only give around an inch of coverage for the area I wanted to fill. With the cans I could take my time (you have to go very slow with the cans, or it can push your plaster board out from the studs) and I could ensure that the entire cavity is filled - making it impossible for bugs and critters to get in there. Stopping bugs from living in the walls was a big deal for me as I'm alergic to bee stings - and this fixed it for me.

I also turned off the electricity for about 15 mins while I sprayed the foam into the walls - as I'm pretty sure the propelant in the cans is flamible (although the foam isn't) and I didn't want a flash fire from the electrical system in my house. It's probably worth mentioning that the wall concerned is also the wall of my house that has the main fuse box in addition to a manual transfer switch.
 
  #7  
Old 01-28-13, 12:59 PM
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Hey Bloop, check this out: Urethane Foam , Expanding Marine Polyurethane Foam

[TABLE="width: 475"]
[TR]
[TD="width: 125"][SIZE=-1]80 LB Kit[/SIZE] [/TD]
[TD="width: 140"] [SIZE=-1]40 Cubic Feet[/SIZE] [/TD]
[TD="width: 120, bgcolor: #E1E1E1"] [SIZE=-1]$264.00[/SIZE][/TD]
[/TR]
[/TABLE]


Not sure if that's better price than the cans you're buying, it seems extremely dense though.

Then I found these cans.

TYTAN PROFESSIONAL Outdoor & RV PRO

Amazon.com: 12 Cans Tytan Expanding Foam Sealant Outdoor R/V Insulate 24oz Polyurethane 4850: Home Improvement

Each 24 oz can is approximately 1.5 cubic feet. At $70 for 12 cans that equals $5.80 a can.

My 19'L 8'T at 4" deep (actually 3.5) wall is 54 cubic feet. Which would take around 36 cans. That's $210 for one wall, the opposite wall is about the same size so say $420 to foam fill all of my walls... Is that a good deal?

Not sure how to calculate how much of the cellulose foam it would take to fill the wall, as I'm sure it would depend on how well I could pack it. Also not sure what would be easier.
 
  #8  
Old 01-28-13, 01:33 PM
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That sounds like a good deal

I would say that does sound like a good deal.

I think that most of these foams are roughly the same. Although I'm not an expert. Whatever you do though, be careful not to go too quickly. Also, I'm not using this on living space walls, as I think it off gases formaldehyde. That said, most engineered woods and foams in our furniture also off gas formaldehyde.

You have to get an applicator gun for those cans by the looks of it. However at least the cans have an accurate volume (to fill) posted on them, which I couldn't find on the cans I used.

Let me know how you get on.
 
  #9  
Old 01-28-13, 01:41 PM
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Just an FYI, polyurethane foam gives off hydrogen cyanide in fires. It's the same as the foam in your sofa and so on. When it burns, the gas can kill you very quickly. It's something we all live with everyday and don't think about much, but it is something to consider. Here's more info on the data, http://www.urethane-jp.org/topics/do...f_english2.pdf
 
  #10  
Old 01-28-13, 01:52 PM
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I really like the look of that marine foam you found, it's pretty awesome as a closed cell foam. I guess you could make a gun to spray it into your walls with an inert gas as the propellant. I might have a sit down later and figure out a design for a system where you only need to purchase the liquids. Most liquids will boil if you reduce the pressure (via a Venturi) low enough, which would also mix the liquids. You've really got me thinking, it's about time we (DIYers) had a cost effective way of doing this for ourselves.
 
  #11  
Old 01-28-13, 02:06 PM
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The marine pour foams are very thin, I think if you mix a couple cups of each part, quickly stir and then put into the wall through a funnel, with a hole drilled at a downward angle it would simply fall to the bottom then expand. They seem to be almost twice as dense as the spray can foams, which I would think means higher R value.

Watch this video of them mixing, letting it expand and then how dense it is when they cut it. - Floatation Foam Product Demo - YouTube

It should be pretty easy to calculate how much mixture, poured into a wall X size, will raise how high and calculate the holes drilled based off of that.
 
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