Heating a garage or hanger

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sfarringer
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Re: Work in Unheated Uninsulated Hanger

Post by sfarringer »

In all except winter, a dehumidifier is a large step toward keeping that mill from rusting up.
I run one in my shop, and one in my hangar. To me, the electricity it takes it worth it. Have to minimize the chance of rusting the lathe, vertical mill, surface grinder, or airplane.
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cessna170bdriver
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Re: Heating a garage or hanger

Post by cessna170bdriver »

Bruce, it looks like you calculated cubic feet rather than square feet. The volume doesn't really mean a whole lot when it comes to heating; its the square footage of walls and ceiling that really count. At 22x25x9.5 you have 893 square feet of walls (including doors and windows) and 550 square feet of ceiling
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Bruce Fenstermacher
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Re: Heating a garage or hanger

Post by Bruce Fenstermacher »

Here is a manual J method online calculator which I found: http://www.loadcalc.net/

I can't help but think this online manual J calculator has a few holes in it. At least for my calculation. It does not have a method to account for a garage door, and I have a 7x20 garage door, and it doesn't have a method to account for the fact that one of my walls is heated on the other side this is the outside wall of my house. With further thought I guess I don't count my heated walls. With this manual J calculator using R11 in the ceiling, the minimum the calculator will work with and no insulation in the walls other than the basic building board and siding which renders R3, calculated out to 52796 BTU. Adding additional R-11 to the walls and raising the ceiling insulation to R-30, about the best I could easily insulate, calculated to 48419 BTU. This for a 14° day, heated to 70° a 56° difference. Probably not many 14° days I'll be heating the garage and I don't need to heat it to 70° so this is the extreme. My more likely heating scenario is 20° to 65° and 45° difference.

Now that we've got this manual J reference lets check it against the other calculation I found. MIles, this calculation uses cubic feet.
  • Calculate the number of British thermal units required to raise the temperature inside the garage to the desired temperature. For this step, you'll need to determine how well the garage is insulated to get the last variable for the equation: insulation quality x total cubic feet x desired heat rise) / 1.6 = Btu required. The forward-slash character in this formula represents the division operator. In this formula, use "5" for no insulation, "1.5" for little insulation, "1" for average insulation and "0.5" for very good insulation. Using average insulation and the calculation results so far, the formula looks like this: (1 x 3,840 x 21) /1.6 = 50,400 Btu.
Matching the manual J numbers I used, here are the numbers for this calculation.
5420.5 cubic feet
56° temperature differential

Code: Select all

            Ins factor	cu ft	T     Diff	BTU 	BTU req.
The example	 1	3840 	21	1.6	50400.0
					
My garage       0.5	5420.5	56	1.6	94858.8
	              1	5420.5	56	1.6	189717.5
	            1.5	5420.5	56	1.6	284576.3
	              5	5420.5	56	1.6	948587.5
As you can see, this calculation, which is all over the internet, doesn't compare t the manual J method.
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GAHorn
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Re: Work in Unheated Uninsulated Hanger

Post by GAHorn »

Bruce Fenstermacher wrote:...

George, why would you think a 50,000 BTU heater would work? Of where you just pointing to the type of heater? I've seen these heaters and the trouble is figuring how much heat I actually need. I could get two of these at 80,000 BTU for a total of 160000 BTUs but I've doubled the cost and fueling trouble.
... :D
I suggested that unit for two reasons.... using my mental-math, I didn't agree with yours .... (I'm admittedly bad at math tho')....and following the suggestion by another that you only needed 40K BTU's ...I thought that the 50K unit might do the job at that level... I also was pointing you to Northern Tool for the best pricing on Mr. Heater Maxx units. For another $75 you could go up to 80K BTUs...https://www.northerntool.com/shop/tools ... _200577751 ...... and the customer reviews of that unit indicate that would be more than sufficient for your workshop. Several users of that 80K unit have larger, less insulated shops than yours and indicate that 70-F can be reached in the frozen room in 15 mins or so, and the unit does not have any trouble keeping the room comfortable while running intermittently.
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hilltop170
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Re: Heating a garage or hanger

Post by hilltop170 »

Hey Bruce!
I was just thinking, I'm surprised somebody hasn't already suggested it! You live in Pennsylvania, lots of coal in Pennsylvania!

You can put a pot belly stove in the garage and just light it up when you need it. You won't have to pay for any electricity or need any of that nasty fiberglas insulation either, the pot belly doesn't care, it heats everything around it. Want it warmer? Just throw in some more coal!

This heater in Fredericksburg at the granite headstone shop looks like it has been there since the first German immigrant died in Gillespie County. The shop doesn't have any insulation, heck, the ceiling isn't even closed it! And they don't need a roof penetration for the exhaust, it's open ended into the attic. Just think how much electricity you could save if you heated your attic! And this heater keeps the whole place warm with it's radiant heat even with a breeze blowing thru.

Just a helpful thought to make your life more comfortable. :lol:

Click/tap on picture to get it right-side-up.
Wood fired heater
Wood fired heater
Last edited by hilltop170 on Fri Dec 29, 2017 3:39 am, edited 1 time in total.
Richard Pulley
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1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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gfeher
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Re: Heating a garage or hanger

Post by gfeher »

Bruce, the formula that you are using from the internet is puzzling to me. Here are a couple of BTU calculators where you directly enter the same inputs you use in your formula (room length, width and height, insulation quality, and desired temperature increase), and they both give results similar to the manual J calculations.

http://www.calculator.net/btu-calculator.html

https://www.simplex.ca/en-CA/tips-advice/btu-calculator

Something odd is going on. Enough said on my part, though. I'll shut up now. :?

I like Richard's suggestion! I have a Tempwood wood stove sitting in my barn that you can have. :lol: The farmer next door gave it to me right after I moved in. I think he'd been waiting to unload it on someone.
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Bruce Fenstermacher
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Re: Heating a garage or hanger

Post by Bruce Fenstermacher »

Richard, I'm thinking you never ran a coal stove. You don't just through in some coal and light it. I know. I've been heating my home with coal as the primary and lately secondary heat source for more than twenty years. I have a 150000 btu coal stove in my basement. and 2 ton of coal in the bin. It's burning right now.

It takes about an hour or two to start the stove which starts by building a wood fire and let that burn down a bit then slowly adding coal. Then you must attend the stove every few hours. Rushing the start process or over feeding the stove can lead to sulfur build up and explosions. Yes I've blown the chimney right off the stove. You can't just shut it off either. And you have to get rid of the coal ash which is a dirty job. In fact as soon as I'm done typing I have to get rid of coal ash. If I had another chimney I'd install a waste oil heater to be honest.

Yes a smaller pot belly might be a little easier and a little faster, it's just the bigger stove in miniature.
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n3833v
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Re: Heating a garage or hanger

Post by n3833v »

Just pile the ash outside for when we get icy, frozen snow and use the ash for traction. It is just as good as sand.
Yes, I agree that coal or wood stoves are great but take time to start.

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170C
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Re: Heating a garage or hanger

Post by 170C »

I'm concerned that Richard is hanging around a headstone store :mrgreen: Somebody better check on him :lol:
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Re: Heating a garage or hanger

Post by ghostflyer »

It’s been a bit of a eye opener reading about the weather conditions that some our members live in , at the moment where I am living it’s a 80 deg F AND 80% humidity. In winter it gets down to around 60 degs and we think that’s cold . In one of the discussions it was mentioned about increasing your aircraft heater efficiency. Well I have only used my heater twice in 10 years . Once to check if it works and once at 10,000 ft when my wife complained her feet were cold. How ever I have walked into my closed hangar in summer and the temperature is internally is over 115 deg f and humidity over 90% .
hilltop170
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Re: Heating a garage or hanger

Post by hilltop170 »

170C wrote:I'm concerned that Richard is hanging around a headstone store :mrgreen: Somebody better check on him :lol:
Frank, the headstone shop is the only place in town that has a sand blaster. I had a spreader bar made for my hoist so I can hoist the 170 and needed to get it blasted before I painted it. It was cold that day and the wood stove sure felt good while I waited.

I am impressed with and do appreciate your concern though. :D
170 being hoisted for wheel bearing clean/repack
170 being hoisted for wheel bearing clean/repack
Richard Pulley
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1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Bruce Fenstermacher
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Re: Heating a garage or hanger

Post by Bruce Fenstermacher »

So lets assume I need 40,000-45000 btu to heat my garage. Looking at George's recommended Mr. Heater 50000 btu heater which is regular $480 (but currently $100 off). I need to install a 3-4 inch vent, likely through my roof and I also need to work out how to hold the propane ie temporary 100 bottle(s). The vent and fuel tank adding expense. Mr. Heater says this heater uses 2.3 lb per hr of operation or .529 gph. At $3.20 a gallon for propane thats $1.68 per hour of operation.

My other option is electric. 50000 btu converts to 14653.55 watts. I could buy one 15000 watt electric heater or 3- 5000 watt heaters and spread them around the garage. problem is the 5000 watt heaters require hardwiring with 10/3 wire. If instead I buy 3 or 4 4000 watt heaters, they have plugs which do need to be plugged into 20 amp, 220 lines which would be 12 gauge wire. With these heaters I could unplug one or more when not heating the garage and move them into the basement which during periods of the year are not heated and gets a bit chilly. This is appealing to me. The issue is the 4000 watt heaters times 3 or 4 cost more than a single propane heater though not more than 2 larger electric heaters than couldn't be moved. Also the smaller heaters have cheaper heat settings, many only low, medium and high rather then a thermostat in degrees. Compared to propane, we pay 13.05 cents per kWh for electricity. 14653 watts is 14.65 kWh. So 1 hour on time at of 15000 watts of electric heat will be $1.90. That's $.20 more an hour than propane.

Decisions decisions.
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hilltop170
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Re: Heating a garage or hanger

Post by hilltop170 »

Bruce Fenstermacher wrote:Richard, I'm thinking you never ran a coal stove. You don't just through in some coal and light it. I know. I've been heating my home with coal as the primary and lately secondary heat source for more than twenty years. I have a 150000 btu coal stove in my basement. and 2 ton of coal in the bin. It's burning right now.

It takes about an hour or two to start the stove which starts by building a wood fire and let that burn down a bit then slowly adding coal. Then you must attend the stove every few hours. Rushing the start process or over feeding the stove can lead to sulfur build up and explosions. Yes I've blown the chimney right off the stove. You can't just shut it off either. And you have to get rid of the coal ash which is a dirty job. In fact as soon as I'm done typing I have to get rid of coal ash. If I had another chimney I'd install a waste oil heater to be honest.

Yes a smaller pot belly might be a little easier and a little faster, it's just the bigger stove in miniature.

You're right Bruce, I have never had the pleasure of starting and stoking a coal fired stove. I did have a coal-fired pizza in Dallas one time though, couldn't eat it and I think that place went out of business pretty quick. It tasted awful.

On second thought, insulation and a propane or electric heater might be the way to go after all. But, if you want to try a wood stove, I have a lifetime supply of dead live oak you are welcome to.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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gfeher
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Re: Heating a garage or hanger

Post by gfeher »

Richard, most of us mere mortals jack up one wheel at a time to clean and re-pack our wheel bearings :D
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hilltop170
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Re: Heating a garage or hanger

Post by hilltop170 »

I know Gene, I did that from 1973 until this year so I know how that works. I do prefer the hoist now that I am a senior citizen.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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