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Advice on heating cabin-Alberta

tractor1971

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Nov 8, 2020
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I will appreciate any advice on the heating question below for a cabin in central Alberta Canada.
Construction:
800 ft, built from insulated aluminum panels, including the floor, on steel beams with 5 ft center
A-frame style with open ceiling living room, bathroom, and bedroom on the main, mezzanine.
Solar with batteries and generator back-up.
Heating:
Primary- Wood stove with slow ceiling fan
Secondary None installed yet, but my friend's plan is-
- non vented propane 10 000 BTU in bedroom
- RV furnace 40 000 BTU with ducting keeping crawl space warm
Water:
From a well, the pipe coming between I-beam, the run is insulated between beams
RV propane with ducting across I-beams to prevent water from freezing
My suggestion:
Vented propane thermostatic controlled 30 000BTU in the living room,
Inline fan 110 V to draw cabin air in crawl space, with adding a thermocube turning on at 2-5C
My concern with the original plan:
10 000BTU too much heat for a small bedroom, they will cook, as well as non vented concerns with moisture.
RV furnace-difficult installation, as the furnace is too big for space left for it, with construction changes that will take a lot of time, holes though I-beam etc, I have my concerns about the RV furnace not designed for continuous use, even as a backup. It also uses 12 V which an in-line fan could be the same, so no power saving there.

Any suggestions or concerns will be appreciated!
 
I'm not a hardware guy and I live in climate zone 1 (south of Miami) so please take this well meaning advice with a grain of salt...

What I've learned/blogged is that air-sealing is the most important thing, followed by insulation. In my case air leaks allow in humidity, which is a "super" heat equivalent as the A/C has to spend energy condensing it, making less cooling available for the house.

The best way to get an air-seal is a couple of inches of sprayed foam. It expands into the gaps blocking air. If you've gaps around those i-beams perhaps some backer rod and foam?

How to Stop Cold-Air Leaks in Winter | This Old House
Imagine this, if you had an 1/8th inch crack around the front door and back door, it's lets as much air into the house as if you had a small window half open.

Another big one is taking air for the furnace from outside. When you pull air from the inside you create a negative pressure in the house, which sucks even more cold air into the house. If the air is coming from below, you might be sucking radon in too.

Not the hardware recommendation you were looking for, but hope it helps!
 
Thank you, Sir. All is windproof in the crawl space, spray foam was used indeed. Was wondering about RV furnace to keep crawl space warm, vs having a duct fan blowing warm cabin air down there?
 
Now that's an interesting idea. I've seen people spray-foam the ground for a moisture/air barrier... certainly utilizing the crawlspace would make ducting heat to any room easier too.

I had a high-efficiency furnace/boiler (Burderous) once (when I lived in Colorado) that had a pipe-in-a-pipe (inner pipe was the exhaust, outer pipe was outside air intake, so the exhaust pre-heated the cold inlet air).
 
Is this a full time residence? I'd be concerned about leaving propane heat running while unattended if it's a vacation home...

Do you have water lines or water storage in the crawlspace? IE: Why do you need to heat it? Oh, sorry, just re-read your post. Can you just wrap the water lines with heat tape that will run off solar?

Also, if crawlspace is insulated well, particularly along the walls, there's a chance it may not freeze? If the floor wasn't insulated so well, the heat from the cabin will filter down a bit, particularly after several days. I guess it depends how cold (and how long it stays there) in Alberta.

Check out this video:
He's using reflectix. But, the concept is the same... His crawlspace didn't freeze
 
I suspect that's more of an IR reflector (aka space blanket). Radiant barriers are effective but need a gap to work (otherwise you get convection), they also get less effective as they get dusty.
 
Do you have water lines or water storage in the crawlspace? IE: Why do you need to heat it? Oh, sorry, just re-read your post. Can you just wrap the water lines with heat tape that will run off solar?

Also, if crawlspace is insulated well, particularly along the walls, there's a chance it may not freeze? If the floor wasn't insulated so well, the heat from the cabin will filter down a bit, particularly after several days. I guess it depends how cold (and how long it stays there) in Alberta.
Just for information. I just installed a new well and piping to the house. I was very concerned with freezing, and spent $600 on a self regulated heat tape.
Then I researched the insulation the diamond mines in the arctic use. Closed cell polyurethane foam is the answer, and they wanted 16/ft for pre-insulated pipe.
I used 4" pool noodles which are closed cell poly foam. I have never yet turned my expensive heat tape on, as in -40C the waterline coming out of the ground is well protected by the pool noodles.
 
I suspect that's more of an IR reflector (aka space blanket). Radiant barriers are effective but need a gap to work (otherwise you get convection), they also get less effective as they get dusty.
Its only a ir reflector, it is not much for insulation...Probally not even an rd value of 0.5....my roof is a rd of 14.....my floor 8...Sorry this was not to brag but this is what i did to my home, as a professional insulator i can not have low numbers in my own home:cool::cool::eek:

@tractor1971
I would like to know the rd value of your alu panels...lets start from there, and what they are made off(inside)
Cous 30.000 btu to get it warm....is a lot.

Oke ventilation is simple to simple to think about.(to get rid off toxic fumes/used air/used propane and living moister sweat and such)
To tell you the truth, i am going to be complete honest, not meant to be insulting...BUT this worries me A LOT. I fully agree with your consurns!!!
Drill a 2 inch hole somewhere in a low corner floor level out of sight. Attaches a 2 inch pvc pipe to it, let that pipe go to the ceiling and connect a minimum of 6 meters/19 yards? of the same diameter pipe into your ceiling.
The fresh cold air will slowly warm up and rise up in the pipe, it will warm up more in the ceiling.
Yes i hear you asking, what about the under pressure inside if that is level with the over pressure outside..
Two things...you will burn wood, it needs oxygen so it will suck thru that pipe.
Second, drill a 2 inch hole at the highest point of your home, make the pipe long enough so it will touch the lowest part of your home.
What will happen in this pipe, the air is warmed up a bit and wants to go up.
This is based on a two person house hold. for every person extra add half an inch to the diameter of your pipes.

Best Igor
 
Couple of thoughts. The 10K BTU non-vent heater in the should have a thermostat (most of the ones I've seen do). If so it being too big should not be an issue as it will just run less time (unless that BR is so small people will be right up against it all night). Also, is this heat to be used overnight when people are there, or will the woodstove be doing the heating then?

It would be good if you had sealed combustion heating appliances (eg no draw of warm inside air for combustion that get
sent out a chimney). Even (maybe especially) in the crawlspace. The non-venting BR heater is OK in that regard, but not sure of the RV heater. Having enough air intake openings to safely run a gas appliance can cause considerable cooling.

Is there a reason you wouldn't just drain your plumbing when you leave for long times rather than keep it filled and have to heat it? A well planned plumbing layout can be drained very quickly, if it was designed with that in mind.

Anyhow, just some thoughts/questions.
 
As I am in your area, I'll kick in my 2 cents. I would be concerned with the non- vented propane as well, and say no to the RV heater. The RV heaters are VERY inefficient. I would say 50% of the heat is in the stack.
The un-vented furnaces are very efficient, and at this time of year a bit of moisture is welcome. The problem with making soggy insulation is spring and fall usage of this furnace. I think he should get a small 45-55000BTU forced air furnace. I have a 50,000btu furnace that heats 1500+ sq ft and my total propane bill for a year, hot water, cooking, and heat is $1800.

I live in a super insulated mobile 20 x 80 mobile home, and the construction is what I would copy if I was your friend. That is, a suspended belly tarp filled with insulation under the floor, and heat ducts and plumbing above the insulation and below the floor. The only downside is trying to get a cold glass of water when all the pipes are warm.
Also, to prevent pipe freezing, the best insulation used commercially, is closed cell polyurethane foam, not the peel and stick Home Depot stuff.
My water line coming up from the ground and down to 7 ft below the ground, is insulated with the largest pool noodles(4")which are closed cell poly. I have never froze my water line at -40C and never yet plugged in my heat trace line. This is very, very effective insulation for pipes.
Hope this is usefull.
 
Only just saw this thread from Last Nov...
I too would be very concerned about a non-vented heater in a space that you're trying to make airtight. There will be a buildup of CO. Nearly all non-vented heaters and fireplaces are equipped (and if not, do not use it) an O2 detector. In a small airtight space, the O2 can easily be depleted. My parents had a non-vented fireplace, you could tell when it was on (smell, humidity), and if running on high too long, turned off with an O2 alert.
I would strongly recommend a vented heater. Takes air from the outside, vents CO to the outside. There are a number of propane and kero heaters out there that would work well. Propane/Natural gas are much cleaner, no smelly kero to deal with, but my kero vented heater uses very little power, runs like an oil furnace, 40K BTU and is pretty efficient with the fuel.
Another option is a pellet stove. It is very efficient, thermostat controlled (on better units), exhausts to the outside. I have one in my family room, does a wonderful job heating, no mess whatever. Down side is you have to have a place to dry store a couple tons of pellets (40lbs per bag, 50 bags per ton/pallet).
 
non vented propane heater will turn it into a moist sauna...
i am in my rv half of my time, and the post about inefficient rv furnace is correct... it works but its terribly inefficent.


use a vented propane unit or a fireplace or both
 
compost...
for smaller offgrid cabins , a compost heating can be quite legit.
the space requirements are hard todo for normal houses,
but for a cabine it is rather doable.

in short : pile of rotting wood generates heat -> bunch of hose to collect that heat into water -> small pump to move the heat -> heat radiators whereever you want the heat.
these bioHeaters usually last for 1.5 - 2 years for each "filling".. it is very passive heating method after you stacked the compost.
Biomeiler_Haufen.jpg
 
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For the secondary heat source your friend might want to try a 12v Diesel parking heater.


Here's a good example of one.

As long as you make sure the exhaust is properly shunted out of the house, as long as you have power and fuel you have heat and it doesn't need to be vented.

If that's too many parts for your friend, they do come in a more compact all in one... even if they are a bit louder due to the pump not being secured to something heavy.

 
I second the diesel heater: you get a LOT more heat out of the same volume of fuel, off-road diesel is cheap, sips the power, and refuelling and fuel storage is as easy as pouring from one jug to another.

I've got one on my 30ft aluminum cuddy cabin boat and even in winter it pumps out so much heat it'll run you out of the cabin even though its sucking in outside air for the heated air intake as it keeps inside the boat nice & dry.

They make diesel hydronic heaters too: https://heaters4you.com look at the binar hydronic heaters. Domestic hot water + hotwater baseboard heating (what we had in Anchorage AK, great heat).
 
I second the diesel heater: you get a LOT more heat out of the same volume of fuel, off-road diesel is cheap, sips the power, and refuelling and fuel storage is as easy as pouring from one jug to another.

I've got one on my 30ft aluminum cuddy cabin boat and even in winter it pumps out so much heat it'll run you out of the cabin even though its sucking in outside air for the heated air intake as it keeps inside the boat nice & dry.

They make diesel hydronic heaters too: https://heaters4you.com look at the binar hydronic heaters. Domestic hot water + hotwater baseboard heating (what we had in Anchorage AK, great heat).
Thing'll run off red fuel oil too. Even cheaper. Burns a little dirtier but that's mostly an issue that sometimes you'll need to run it at full power to clean it out.
 
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