Author Topic: Heating in extreme cold  (Read 10409 times)

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Offline upa

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Heating in extreme cold
« on: January 05, 2010, 07:43:05 AM »
Went to the cabin last week. It's been unoccupied for the last couple of weeks when temps had dropped to -38 celcius irrespective of any additional windchill factor. So the cabin was nice and frozen. I had heck of a time even lighting the wood stove everything seemed too cold to ignite. Note to self - butane lighters don't work when this cold, bring matches. Tried to start my mr Heater 18,000 btu propane heater but the propane would not flow. Once I did manage to start a fire I had to keep the stove on thermo nuclear level ( flue pipe temps 800-900 F)for probably a good 16 hours( it took 4 hours to get to 0C ! or 32F) before the house actually reached a reasonable warm thermal mass. The house does have good insulation at this point. Has anyone had any luck with any auxillary heating devices in extreme cold for the occasional winter use cabin? I'm thinking propane is out unless I bring a warm tank.
« Last Edit: January 05, 2010, 08:01:27 AM by upa »

Offline rocking23nf

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Re: Heating in extreme cold
« Reply #1 on: January 05, 2010, 07:52:00 AM »
so you live in alberta also huh.


Offline upa

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Re: Heating in extreme cold
« Reply #2 on: January 05, 2010, 07:59:29 AM »
Close enough, Manitoba  :)

Offline MountainDon

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Re: Heating in extreme cold
« Reply #3 on: January 05, 2010, 08:31:09 AM »
Propane does create problems at very cold temperatures. At -45 degrees F (-43 c) you could have an open bucket full of propane and it would not evaporate. So at -38 C you have a very low vapor pressure, not enough to run some appliances.

Were you using a small portable tank like a 20#?  Larger tanks will work better in cold temps. A dual stage regulator may also work better. The regulators that attach directly to a portable tank are single stage most often. Single stage are more prone to freezing up as the propane is used.

At times like this it would be nice to have two wood burning stoves.



I wonder if this is one of the reason rwanders in Alaska uses a fuel oil heater/furnace?
Just because something has been done and has not failed, doesn’t mean it is good design.

If you didn't have the time or money to do it right in the first place, when will you get the time and money to fix it?

Offline rwanders

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Re: Heating in extreme cold
« Reply #4 on: January 05, 2010, 11:24:45 AM »
Propane does create problems at very cold temperatures. At -45 degrees F (-43 c) you could have an open bucket full of propane and it would not evaporate. So at -38 C you have a very low vapor pressure, not enough to run some appliances.

Were you using a small portable tank like a 20#?  Larger tanks will work better in cold temps. A dual stage regulator may also work better. The regulators that attach directly to a portable tank are single stage most often. Single stage are more prone to freezing up as the propane is used.

At times like this it would be nice to have two wood burning stoves.



I wonder if this is one of the reason rwanders in Alaska uses a fuel oil heater/furnace?



I originally considered propane for heat but chose fuel oil primarily because it is more efficient (higher btu per gallon) but also because of the potential problems in very low temps. I do use propane for cooking and for hot water and haven't had any problems using a 100 lb tank. Trying to warm up a cold-soaked cabin can be a real problem----so far, I have been keeping the cabin warmed to 54F and so it only takes about 20 minutes to warm UP TO 70F after I arrive.  I burnt just over 300 gallons of fuel oil for the first whole year----not too bad---about $50/mo average. 
Rwanders lived in Southcentral Alaska since 1967
Now lives in St Augustine, Florida

Offline Redoverfarm

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Re: Heating in extreme cold
« Reply #5 on: January 05, 2010, 11:41:53 AM »
rwanders you must have that cabin insulated real good.  That is a good consumption for that extreme climate.  I would probably use that much in the lower 48 states.  With the assistance of a wood stove and gas heat I normally burn about 150 gal of propane a winter.  But it is not in comparison to your temps.  Maybe now but not usually that cold. ;)

upa been there and done that with the butane lighter this morning.  I did have matches though.

The inside temp at the cabin this morning was 23F with outside at 17F.  in three hours with two wall gas heaters I managed to raise it to 53F in 3 hours.  Comfortable working climate but to stay in it I would probably have to start a fire in the fireplace and wood cookstove for a night to make it comfortable.

BTW I didn't have any problems with the propane but I have a dual stage regulator and 500 gal tank.  

Offline Arctic Builder

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Re: Heating in extreme cold
« Reply #6 on: January 05, 2010, 01:37:55 PM »
I have all of you beat for the most extreme cold. I live in Canada's arctic territory of Nunavut and trust me it gets cold. This morning we had a windchill factore of -52 C. For the last couple of years I've been heating my cabin with a Colman stove without much success, no fun waking up in the middle of the night to refill the tank. This year I plan on getting something better for a heat source, I'm still debating between oil and wood. Both would have to be brought out by snowmobile in the winter and since there are no trees on the tundra I would have to collect wood fron the dump.  ???

Offline upa

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Re: Heating in extreme cold
« Reply #7 on: January 18, 2011, 06:56:50 AM »
Well I thought I would update this post, as I tried a few things a little differently this heating season. We went up this weekend in a balmy -22C or -30+ with windchill. I have since installed a 45,000 btu forced air propane furnace to augment the wood stove. The furnace is feed by 100# tank and 30# tank via a two stage regulator. At this temp the propane would flow but poorly via 30# tank, but #100 tank had no problem supplying sufficient pressure.

My wood for the stove was extra dry and I kicked it off no problem with the help of a small packet "zip" fuel lighter and match stick. These are usually in the bbq section of most stores. They are a little(inch square) plastic wrapped, fuel impregnated cubes. Just touch a match to the plastic and away she goes.

Between the furnace and woodstove we had the 1000sq ft cabin heated from 10F to 72F in 2 hours. This would have taken 5-6 hours last year. About 3 hours after we arrived we only had the wood stove on a low burn when one of our neighbors come by. It was so warm he could not believe we just came to a cold cabin he really thought we had been heating the cabin while we were away.

Offline MountainDon

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Re: Heating in extreme cold
« Reply #8 on: January 18, 2011, 09:19:58 AM »
Good to hear the warm up went easier this time.

Just because something has been done and has not failed, doesn’t mean it is good design.

If you didn't have the time or money to do it right in the first place, when will you get the time and money to fix it?

Offline rocking23nf

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Re: Heating in extreme cold
« Reply #9 on: January 18, 2011, 10:55:13 AM »
what kinda cost to install a propane system like this? and do you have air ducts like a house would have? my cabin is mostly open, and propane sounds like a good option over electric.  I currently use 3 electric portables, and 3 baseboard heaters. Im in alberta, but havent been using the cabin in the winters yet. Last year I was out in early april, it hit -5 overnight, and the cabin stayed at 21 degrees with just the 3 electric portables going.



Offline kev_alaska

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Re: Heating in extreme cold
« Reply #10 on: January 18, 2011, 11:11:15 AM »
We keep the Toyo at the minimum 50 degrees when we leave the cabin. Each weekend we come out, it takes about an hour to get the cabin to a reasonable 65 with the woodstove. The Toyo uses about a gallon and a half or so a day when it is on low.
Much easier than having to haul freezable items back and forth to town.

kevin
Stealing ideas from John, PEG and Glenn for a several years now.......

Offline upa

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Re: Heating in extreme cold
« Reply #11 on: January 18, 2011, 12:32:13 PM »
what kinda cost to install a propane system like this? and do you have air ducts like a house would have? my cabin is mostly open, and propane sounds like a good option over electric.

Propane vs electric was not much of an option as I am offgrid. It's primarily wood heat with propane supplement.  The furnace I have is a 45K btu MrHeater forced air propane furnace. It's really designed as a shop/garage heater, see northerntools website for more info. It's not a sealed combustion unit so you still should make some accomadation for a fresh air supply.   It's rated at 80% burn efficieny, so pretty economical to run. I mainly selected this unit based on cost, size and the fact I can direct vent it out a wall horizontally. My local  Princess Auto(kinda like Northerntool in Canada) was blowing them out last spring for $300 including the vent kit. The black pipe, assorted fittings, regulator, thermostat and wiring probably cost me another $300 plus propane tanks. Comes with detailed code appropriate install instruction so a relatively easily DIY project. Took me a Saturday afternoon.

As my cabin is fairly open I opted for no ducting, the furnace hangs from my northeast main floor rafters. The blower fan has lots of power and throws a strong draft right across the 32 ft width of the cabin. The 2nd floor is generally little cooler but for the most part heats up well with the simple convection circuit I have going with a few well placed vents on the second floor for a gravity based cold air downdraft return.

Offline rwanders

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Re: Heating in extreme cold
« Reply #12 on: January 18, 2011, 02:29:42 PM »
Lots of insulation really helps and fuel oil offers about 40% more btu per gallon then propane-----also use a good heater--TOYO is pretty much the standard in Alaska. My cabin is a 24x24 1 1/2 story with large loft and 12' walls and 12/12 pitch cathedral ceiling. I put 11" pf spray closed cell foam in the roof and R21 fiberglass in walls and floor. It has nine large windows plus full glass double door on first floor and single full glass door on second. Keep it heated to 54 while gone and it heats up to 68/70 within 40 minutes even at -35F. Almost went with propane until I found btu information on internet. I burn right at 300 gallons per year of fuel oil. Located about 90 miles north on Anchorage where winter temps regularly drop to -40 and sometimes to -55
Rwanders lived in Southcentral Alaska since 1967
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Offline pocono_couple

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Re: Heating in extreme cold
« Reply #13 on: January 18, 2011, 06:25:43 PM »
hi upa,  i was just looking at the northern tool catolog this afternoon.    our house is about 1100 square feet - two floors with a basement.   we just put in a jotul gas stove ( 40,000 btu lp)   and it seems to heat up the whole house after about 4-5 hours..  but i was thinking about installing a mr heater in the basement..  i liked the idea that they are vented directly outside..  you mention, however, that you still need to provide a fresh air source?  can you tell me a little more about that?

any thoughts on the non vented gas heaters?  my instinct tells me to steer clear of them, but there are a lot of them on the market...


Offline pocono_couple

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Re: Heating in extreme cold
« Reply #14 on: January 18, 2011, 06:32:59 PM »
oops.. i also wanted to know about how you placed the vents in your second floor.   i am interested in cutting some vents in my second floor as well...   our stove is kind of central on the first floor.   i was thinking about cutting two vents in each of the upstairs bedroom,  one close to the stove and one at the opposite end of the room..   thanks!

Offline kev_alaska

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Re: Heating in extreme cold
« Reply #15 on: January 19, 2011, 02:07:08 PM »
Non-vented propane heaters of any kind put a lot of moisture in the air. Lots of them are on the market as you mentioned, most are used for temporary heating.
Stealing ideas from John, PEG and Glenn for a several years now.......

Offline pocono_couple

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Re: Heating in extreme cold
« Reply #16 on: January 19, 2011, 02:24:11 PM »
thanks,  that is the kind of info I need, and the basement already has enough moisture !!   

Offline firefox

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Re: Heating in extreme cold
« Reply #17 on: January 19, 2011, 02:39:44 PM »
I was wondering if it would be practical to hook up a solar "water" heater just to keep the fuel warm while you are away. Obviously you would use a non freezing fluid instead of water.
Bruce
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Offline MountainDon

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Re: Heating in extreme cold
« Reply #18 on: January 19, 2011, 03:38:25 PM »
A big NO to unvented heaters for anything but temporary use.

It's not just the water vapor but there could be incomplete combustion and other dangers.

Just because something has been done and has not failed, doesn’t mean it is good design.

If you didn't have the time or money to do it right in the first place, when will you get the time and money to fix it?

Offline Arky217

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Re: Heating in extreme cold
« Reply #19 on: January 19, 2011, 06:56:27 PM »
A bigger wood stove also works.

The 12 x 16 cabin I built in Alaska had no insulation whatsoever, but I had no problem heating it at 60F below with the stove I made from a 55 gal barrel.

Of course, to stay fairly warm, you didn't get too close to the outside wall. ::)

Arky

Offline rwanders

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Re: Heating in extreme cold
« Reply #20 on: January 19, 2011, 07:12:40 PM »
 :) Been in that kind----you need to keep revolving like a chicken on a spit!
Rwanders lived in Southcentral Alaska since 1967
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Offline upa

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Re: Heating in extreme cold
« Reply #21 on: January 25, 2011, 11:31:28 AM »
oops.. i also wanted to know about how you placed the vents in your second floor.   i am interested in cutting some vents in my second floor as well...   our stove is kind of central on the first floor.   i was thinking about cutting two vents in each of the upstairs bedroom,  one close to the stove and one at the opposite end of the room..   thanks!

You have the right idea. It's fairly simple, my stairwell to the second floor(which is next to my central wood stove) basically acts as a giant warm air convection feed duct and several vents holes cut into the edge of  2nd floor bedroom's floor serve as my gravity cold air return. Generally works fine.

If you are seriously thinking of adding propane furnace, don't entirely discount a conventional high efficiency unit with appropriate ducting. It's a little more work for sure but then you can also accomadate for central air in the future if you wish. I only went this way because I found my shop furnace cheap, but for maybe $600-700 more I could have set up a conventional high efficiency forced air unit.

Whatever you do, stay away from the non vented heaters, not only do I think they are funadamentally dangerous,  as previous posters have mentioned they produce a tremendous amount of moisture. I have seen really bad mold problems in houses that were very tight and used these heaters.
 
« Last Edit: January 25, 2011, 11:57:02 AM by upa »