Retrofitting a garage to be heated.

[DoSumpthin]

I'm trying to retrofit my garage to maintain a heat in the winter as I need to make more use of it now than previously. I'm trying to balance price and efficiency.

SPECIFICATIONS:
Located in New England, 14x24 with a 10' ceiling.
2x4 walls with fiberglass insulation, 2x6 ceiling w/fiberglass

I am using:

• Sterling GG45 propane garage heater
• Concentric venting kit
• CSST gas line (with bonding clamps)
• 3" Poly-iso factory second rigid foam
• Lots of caulk and expanding foam in a can

I have found this forum very useful so with the hope of contributing back I will post some pics and video as I make progress. Comments are welcome.

Thank you.

 

[Thumper68]

If you are going to be throwing sparks, welding grinding make sure you cover up that foam, or you won't have to worry about heat, you will be able to stand back 20 feet and roast marshmellows.

 

[DoSumpthin]

If you are going to be throwing sparks, welding grinding make sure you cover up that foam...

Good point my friend. However, in my case, the foam is going on the outside of the structure.

 

[neel2008]

Id really look at the costs of propane vs other options..... For me I calculated natural gas would be the most efficient if it was available in my area, followed by a small electric heater like a fahrenheat 5000 watt.... propane is kinda expensive here....Im also looking into adding a homemade "solar heater" as people seem to be getting decent results from them for no more money that they have in them....

 

[DoSumpthin]

Id really look at the costs of propane vs other options..... For me I calculated natural gas would be the most efficient.

Hey, thanks for your input. Indeed, I have explored fuel options. So far as I can tell there is no place to buy natural gas in my area.

Home heats with wood. Asking the wife to feed a garage stove during the day wouldn't be in my best interest.

This garage is going to be really tight when I'm done, which I am really banking on for effeciency. My only concern is my heater is too big at 45k btu's but it's too late to change that now. I'm looking at a thermostat with a wide differential to prevent the heater from cycling too frequently. I don't need to maintain a 2 degree flux in the garage.

 

[theoldwizard1]

Check into a min-split heat pump. It will cost more to install, but it will cost less to operate.

I would add extra insulation in the ceiling if possible. Not sure what you are going to be doing in your garage, but the floor will always be cool.

 

[danfromsyr]

I bought a used pellet stove from the local Craigslist and one thing that's nice with it is that it'll run low/idle speed for 24+hours. while not cheaper than NG I know how much it costs as I feed it ~$5 bags..
I don't like the amount of maintenance it takes at times.. but a quick shop vac **** time to time extends my cleaning cycles.
though you may not be able to or like using an open flame heat device in a shop/garage

 

[rancherbill]

-Wear a sweater
-programmable thermostat. Set it for 45 normall and 60 only for the days you will be using it.

 

[corncob]

What about your garage door(s). Is it insulated?

 

[DoSumpthin]

What about your garage door(s). Is it insulated?

Yes, it is insulated but I think I am going to temporarily frame over the outside of the door for the winter to seal it up.

 

[DoSumpthin]

Made progress...

I am using factory seconds of Poly-Iso foam. This came in at about 1/3 the price of new however it is tapered so I have to glue two pieces to make a 3" thick sheet. Here you can see I have assembed some 8x4 and some 10x4 sheets.

In an effort to make things as tight as possible I have notched the foam for my roof trusses. This was a pain in the ****. Even though it was 40 degrees outside I was sweating profusely in the attic with a respirator on. Miserable!

In the attic I had to cut an opening large enough to get the foam sheets into the small area. Once finished I will put studs back in under that temporary header. (lots of heavy snow here in winter). I will be installing OSB over the top of the foam since this will be a storage area.

A decent fit around the trusses. Before I'm done I will crawl around with a can of spray foam to get in the nooks and crannies.

Finally, the heater. Sterling GG45 with separate combustion.

 

[toyotadriver]

Looks like you are doing a very nice job! The 3 inches should substantially increase your insulation value in the attic. I live in a warmer climate than you but it still gets cold here. I have a shop building with 3 inches of XPS foam sheeting (double thickness of 1.5 inch foam sheets). It stops almost all the heat gain (summer) and heat loss (winter) from the roof. The windows and doors lose/gain more heat than the roof does!

Couple questions:

How much is the per 4x8 sheet cost for your factory seconds foam sheets?

How much was the heater? I have the Mr. Heater version of but that Sterling looks very well made.



Looks great. Look forward to seeing more pics!

 

[BoostAddiction]

Interesting to see tapered foam sheets- that's a new one for me.

You should have a great start on insulating the shop. But as you probably already know, the details are what makes the job.

If you have a man door, perhaps you could do a blower door test. That would give you a baseline for future improvements, as well as a good sense of where you are today.

If you combine that with a smoke machine (using neutrally buoyant smoke) you can see where the major leaks are and attack them with spray foam. I assume you are taping the sheets, though I didn't see that in the pics.

Have you validated that external insulation like you are using will allow the walls to dry in the direction you need?

 

[DoSumpthin]

How much is the per 4x8 sheet cost for your factory seconds foam sheets?

It comes out to $15 per 4'x8'x3" (Local building supply house wanted $34 for a 2" sheet)

How much was the heater? I have the Mr. Heater version of but that Sterling looks very well made.

Just a hair over $500 from littlegreenhouse.com, plus about $50 shipping. I felt that was pretty reasonable.

Interesting to see tapered foam sheets- that's a new one for me... ...Have you validated that external insulation like you are using will allow the walls to dry in the direction you need?

I was told the tapered sheets are intended for use on flat roofs. Tapered so water can be channeled as desired. They have a fiberglass facing, I plan on taping the seams but haven't researched what kind of tape will stick to the rough fiberglass. I have been slathering silicone between sheet edges before butting them together.

I haven't done any form of testing or analysis. My building was pretty breezy before due to the garage door so I am simply doing my best to tighten it all up then might try testing for weak spots later.

 

[toyotadriver]

Great price!

Would love to see more pics including what the shop looks like.

Are you going to put the foam sheets on the outside walls? If so, how are you planning to finish the exterior?

 

[DoSumpthin]

Great price! Would love to see more pics including what the shop looks like.

Are you going to put the foam sheets on the outside walls? If so, how are you planning to finish the exterior?

Sure thing... I'll post more pics as I go.

Yes, I am putting foam on all the outside walls and in the ceiling then tying it all together at the edges. As far as finishing the exterior it will be either vinyl or metal siding, but for this year just house wrap and strapping.

Supper's over, now back out to the garage!

 

[hedhunter9]

Yes, the tapered foam sheets are used in roofing.. and some of the sheets are 4 inch thick with out a taper.
We got 8 Truck and trailer loads of it from a place about 20 miles from us.
For FREE ! We used a long razer knife to cut the sheets. We used 6 in. in the walls of my wifes 30x40 pole barn.. and 8 inch in the ceiling.. (then sheet rocked over it) as she raises parrots and we have to keep it heated 24x7... ( it has one 6 foot elec. baseboard heater in the half that is heated)

I have half my 30x40 pole barn walls done and am getting ready to do the ceiling after I put the ceiling in..
I sold one trailer load of the foam for $100, to go buy some regular fiberglass rolls to use in the ceiling though..as it is much easier and faster to put in.. So wont have any cost in insulating it either...
The place we got the foam from, normally sells it by the bundle, but now and then, they have too much of it sitting around, and if you time it right, you can get it FREE !
I like FREE ! ;-)

Bob

 

[DoSumpthin]

UPDATE:

Up in the eaves I custom cut blocks that plug the ends of the ceiling joists. These **** up against the attic floor foam and the exterior wall foam. I then shot canned foam into the nooks and crannies. I figure if I make the building "too tight" I can easily remedy that later.

This mockup from scraps shows how my foam pieces interlock. All foam to foam mating surfaces are sealed with canned foam, caulk, or liquid nails. I had to cut a taper at the top to allow cold air from the eaves to flow into the "cold-space" attic.

Here is the back window opening. This shows all the layers. I later encapsulated these exposed layers with ice and water shield to consolidate them.

Here is the side and back. I managed to get the wrap up on the rear. I am using mix-match partials rolls of different wraps that people gave me as leftovers, yard sale pickups, etc. Started to get the strapping put up enough to hold until next weekend. I used my flatbed truck as makeshift staging.

I think my heater is going to be way too big.

 

[toyotadriver]

Looking great! That's going to be VERY well insulated!! I'm looking forward to hearing your wintertime experience going to the much higher level of insulation.

 

[toyotadriver]

Any updates?

 

[DoSumpthin]

Yeah, been working hard.

Last weekend I got the heater installed and tested although I am not using it yet since I am finishing the insulation this weekend.

I temporarily mounted 4 2x4's and "walked" the heater up them using clamps.

Hookups in place. NOTE: Venting not sealed or screwed yet. I did that after testing.

Done deal! This Sterling heater is MUCH quieter than I expected!

 

[sr71]

Nice job - clever lifting rig you made. ..don't forget condensation is your enemy when you heat a garage. Once you start heating you can't stop ...if you do ..condensation is likely=rust. I keep my garage thermostat set at 45... crank it up to 69 when I'm working.

 

[jannan]

Great job! Really liked how you hoisted the heater! May I ask where you sourced the "factory seconds" foam? Thanks.

 

[DoSumpthin]

...Once you start heating you can't stop ...if you do ..condensation is likely=rust.

Yes, same tactic here... maintaining 50 degrees +/- and turning it up when occupied. Seems most reasonable.

Great job! Really liked how you hoisted the heater! May I ask where you sourced the "factory seconds" foam? Thanks.

A local small business sells the foam. I hired a flatbed tow truck to pick it up and drop it off at my house.

 

[anthony666]

looks like it was tons of work man .. good job

 

[jmitchell1988]

I am new to the site. Seems like a great resource to have going forward! Thanks in advance for all your help and support.

I have been researching wood stoves in the garage all day! I have some specific questions and wondering if someone very informed could help - I was given an old tall wood stove and want to put it in my garage. The previous owner heated the garage through a concrete chimney. I am VERY new at this. Can someone explain how to attach, and what Ill need to buy? thanks so much. Looking to heat the garage for all the people coming on Thanksgiving!
Cheers,
Jon

if the attached image doesn't work then send me an email - [email protected] - and I will send it that way. Thanks.

 

[CNGsaves]

Yeah, been working hard.

Last weekend I got the heater installed and tested although I am not using it yet since I am finishing the insulation this weekend.

I temporarily mounted 4 2x4's and "walked" the heater up them using clamps.

Hookups in place. NOTE: Venting not sealed or screwed yet. I did that after testing.

Done deal! This Sterling heater is MUCH quieter than I expected!

Nice solution to "walk-up" the heater to it's final place !! You might want to find GJ thread which has all the heater install methods, as yours is very innovative and should be listed.

I see problem with Drip Leg for the gas fuel line. It should have 90 degree turn when Natural Gas flow has to change directions up (see example picture below). Yours goes straight through which could possibly let debris get into your heater.

Thus, I'd recommend you just change T to be vertical rather than horizontal, and move the drip part to bottom of T. Yellow flex line would go directly into the T. Then, another 90 at top so NG goes into heater above the T.

 

[DoSumpthin]

I see problem with Drip Leg for the gas fuel line. It should have 90 degree turn when Natural Gas flow has to change directions up (see example picture below). Yours goes straight through which could possibly let debris get into your heater.

I had this thought too but with the separate combustion intake duct there isn't room for the gas line to come from above. Or, alternatively, I would need to move the gas valve to the other end of the flex hose to make room. Sterling's installation guide shows both the way you suggested and the way I have it as acceptable methods. I do concur however that debris could blow past the drip leg so it is not an optimal setup.

Looking at the diagrams though it appears I am supposed to have the gas valve attached directly to the heater, then the T, which might resolve this. I will investigate further. Thanks.

 

[DoSumpthin]

UPDATE:

LAST WALL INSULATED - Did the remaining wall which is indoors of my big garage.

GARAGE DOOR WEATHERSTRIPPING - Finish boards around the 9'x8' overhead door and installed vinyl weatherstripping.

ENTRY DOOR - I have a double wide insulated entry door going from my garage to the shop. I kind of just threw it in there a few years ago. I have now squared it up, mounted solid, and sealed around it.

FIXED LIGHTING - Half my lights didn't work. Almost 10 years of working in poor lighting, you would think I would have taken a few hours BEFORE NOW to fix it. Ballasts were wrong.

TO DO: Foam over outside of overhead door. Next year might build some lightweight foam barn doors.
TO DO: Finish some minor wiring of fixtures and panel.
TO DO: Run ethernet and phone lines from house. (Need gigabit LAN speed)
TO DO: Repair some drywall I had to open up.
TO DO: Finish boards around window. (If I don't do it now it will never be done)
TO DO: Cleanup

 

[toyotadriver]

Your latest pics aren't showing

 

[DoSumpthin]

Just reporting back. I am pleased with the heating results. I have two 100# propane tanks, had them filled 3 weeks ago. I kept one closed and have been running off one tank until today. I felt I was pressing my luck so I switched to the other.

I am using a mechanical thermostat with an adjustable differential up to 12 degrees. When I keep it set at 55 with about an 8-9 degree differential the heater fires every couple hours for about 10 minutes. These are guestimates. I turn it up when I am out there.

I have just built my own thermostat from an arduino microcontroller. I have used a relay and diode that I salvaged from an old dialup modem to switch the thermostat wires. It seems to work well but the temperature sensor I was using (DHT11) reports in a resolution of 1 degree celsius which converts to a resolution of 1.8 degrees fahrenheit. I have a new sensor coming that offers more accuracy.

I plan to add functionality that will record statistics to an memory card including indoor/outdoor temp, duration and time between heat cycles, etc. I think I will also build in a kill function so that it will shut down the heating system if the heater runs too much... in case the door gets left open or something, so it doesn't use up all my propane. Also I want it to email or text me if there is an issue. Getting there!