Highly insulated house and stove size

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frozenfiber

New Member
Aug 9, 2019
5
alaska
Our new construction house has R44 walls and R60 ceilings. The living space is 1,300 sqft including a loft for the bedroom and an attached shop that's 1,200sq ft with 16ft walls. Our question is how big of a stove to install and will heat all 2,500 sq ft and not cook us out. There is a door into the shop from the first and second floor that can be opened to heat it. We live in the mountains of Alaska with an average winter temps of about 10deg last years low was -30 for a week.
 
Initial thought is that I would consider a 2 stove or 2 heating units setup. Load up a few pics of the place. Include the interior layout. Naturally we will need a few pics of the scenic mountains of Alaska as well:cool:
Welcome to Hearth. Guessing you will get plenty of recommendations.
 
Read up on Pointdexter's AK posts.
 
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[Hearth.com] Highly insulated house and stove size [Hearth.com] Highly insulated house and stove size [Hearth.com] Highly insulated house and stove size [Hearth.com] Highly insulated house and stove size [Hearth.com] Highly insulated house and stove size Here are pictures of the living space. The green chair is where the stove will go the door way on the same wall is to the shop. there is also a door from the upstairs to the shop. I should clarify I am not new to heating with wood in Alaska. We currently have a napoleon in our 1000sq 80s house and I was raised with wood only heat. Our issue is that the new house has 3-4 time the wall insulation as most houses and it super efficient. Our struggle is figuring out how to heat the space with the right sized stove so we are not to cold or to hot. The shop is expected to stay cooler than the living area.
 
Blaze Kings (cat) and Pacific Energy (non-cat) stoves are popular in your area for their flexibility in burning temps. The Blaze King will burn low and slow and may be a better fit. They are thermostatically controlled. That's why I suggested you read up on Pointdexter's experiences.
 
Here's a pic of Homer in April of this year...[Hearth.com] Highly insulated house and stove size
 
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While R44 walls and R60 sounds amazing to myself being in NJ, for you guys in Alaska that's just in the above average area, BG recommended @Poindexter's threads & posts because he's gone through the paces on the outskirts of Fairbanks.
Personally the BK stove is built simply enough for a laymen to maintain, but offer excellent efficiencies on different heating levels. The output can be turned low and trickle 15k btu's an hour with an extended burn for 15-20 hrs per load, or it can be ran on high and pump out 55/60k btu's an hour and burn like all other stoves with a 6-8 hr loading schedule.
 
Give it time... Alaska may have NJ weather, in a few more years, looking at the current trends.
 
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Give it time... Alaska may have NJ weather, in a few more years, looking at the current trends.
They certainly did this spring. 90+º in Anchorage.
 
What are you doing with/ in the shop? If you are moving diesel equipment in and out three times a day that would be different than bringing in some lumber in August and making guitars all winter with the door closed.

A previously suggested, I would likely go with a pretty fair sized cat stove for the main living area, like a BK Princess or a BK size 30 box or similar. You can turn those own pretty low and not have to reload them so often.

Based on your posted temps I am guessing Alaska rather than Brooks range and a BK King would likely be overkill.

For the shop it just depends on air turnovers. If you have an overhead door and service front end loaders I would suggest two of the biggest rip snortingest non cat stoves you can find, just the buckets will suck up a bunch of BTUs when you bring one in from the yard.

So for the house I would be looking for a highly efficient catalytic equipped stove with 35-45k BTU max output and probably about 5 cords of spruce seasoned to 12-14% MC per winter, with two years worth (10 cords) on hand.

The shop is the wild card. It is like having kids at home. One of my boys loved to open the main door of the house so he could see out the window in the storm door and watch the world go by. For hours at a time. At -20dF. Once he got tall enough to see out the regular windows my oil bill dropped.

If you are going to be closed up in there all winter and pull out one brand new hand made boat in April a robust cat stove should keep it warm, but if you are bringing in tons and tons of cold steel day after day you will want a couple big boys that can burn down a big pile of wood in a hurry, and many many cords of fuel.
 
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The shop in the winter will just be for personal projects and parking my husbands work truck. We are up at Hatchers pass in Wasilla. We get lots of snow and it stays colder than in town.

How does one calculate how many BTU an hour we should aim for? I know last summer I found a site where I could calculate our heat loss at various temps and it was next to nothing. Guess I need to find that again.

The fireplace stores are saying we need like the BK king because of the sq ft. But I have talked with energy people from the cooperative extention both here and NY they both thought a big stove would be hard to run efficiently without over heating the house and maybe smaller but again had no real idea how much smaller. I love being warm but not back in Missouri summer warm.
 

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Here is a 1am or 2am summer dusk on June 20th. Sure do love June and July here. The sun never tells you it's time to stop having fun.
 

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Here is a 1am or 2am summer dusk on June 20th. Sure do love June and July here. The sun never tells you it's time to stop having fun.

And therein lay the problem last time I was up your way;lol You are in a really nice area. When you say lots of snow.... You are not kidding a bit.
 
The drive up the pass and back down to Talkeetna should be on every visitors list....that and the drive down the Kenai P to Homer.
 
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small fires can be built in large stoves or just a small fire maintained . You really can't push a little stove to the level of a large one with any type of lengthy burn time. You would get more mileage of your primary fuel up there from a cat equipped stove, that said perhaps one of the newer hybrid stoves ( secondary burn tubes + cat) might be something to look at.
 
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The shop in the winter will just be for personal projects and parking my husbands work truck. We are up at Hatchers pass in Wasilla. We get lots of snow and it stays colder than in town.

Beautiful beautiful place. Heating my wife's car back up to household ambient every night after she parks outdoors at her office all day is one of my largest single BTU eaters. Can you wall the garage area off from the shop, or not so much?

How does one calculate how many BTU an hour we should aim for? I know last summer I found a site where I could calculate our heat loss at various temps and it was next to nothing. Guess I need to find that again.

I don't know how to calculate it. I heat 1200sqft in Fairbanks with R40 walls and R60 ceiling. ~40k BTU/ hr is enough to get the place warmed up when it cools off, and a stove that can be turned down real real low will keep from cooking you out.

Once it's built you could get an air door test to see how well sealed it really is. Another useful thing to know is your degree loss per hour. If I turn all the heat sources off my house will cool from +70dF to +69dF in about one hour when outdoor ambients are in the zero to -20dF range. Below -35dF i start losing many degrees per hour and have to generate a fair number of BTUs.

The fireplace stores are saying we need like the BK king because of the sq ft. But I have talked with energy people from the cooperative extention both here and NY they both thought a big stove would be hard to run efficiently without over heating the house and maybe smaller but again had no real idea how much smaller. I love being warm but not back in Missouri summer warm.

I personally would plan to heat the shop separate from the house. On paper you could do it all with a BK King, but that kinda sorta means having an overhead garage door in the dining room.
 
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The shop in the winter will just be for personal projects and parking my husbands work truck. We are up at Hatchers pass in Wasilla. We get lots of snow and it stays colder than in town.

How does one calculate how many BTU an hour we should aim for? I know last summer I found a site where I could calculate our heat loss at various temps and it was next to nothing. Guess I need to find that again.

The fireplace stores are saying we need like the BK king because of the sq ft. But I have talked with energy people from the cooperative extention both here and NY they both thought a big stove would be hard to run efficiently without over heating the house and maybe smaller but again had no real idea how much smaller. I love being warm but not back in Missouri summer warm.

I hate to agree with a fireplace store, but I agree with your fireplace store. The King turns waaay down. The Princess turns down a little lower than that (I burn mine 24/7 straight through 50°+ days).

Firebox size isn't tied to burn rate if you have good control of your combustion air supply. I wouldn't worry that the King was too big.

I wouldn't ask any space heater to heat the shop also, because you'll be running it up to 100 degrees in the house to try to get the shop to 60. A second stove in the shop will do better.
 
. The Princess turns down a little lower than that (I burn mine 24/7 straight through 50°+ days).
You mean, you burn 40/4.2 or 36/4.7 on those days, don’t you?
 
One of the other major considerations is finding a stove with a direct outside air connection, with a house as tight as your will want a dedicated air source for just the stove, even with a home make up / air exchanger, a dryer, hood vent or bathroom fan can cause a smoke odor if the stove is running and competing for air.
 
You mean, you burn 40/4.2 or 36/4.7 on those days, don’t you?


I must be a little dumber than usual today, because I'm going to have to ask you to explain that one to me... I assume it revolves around replacing hours and days with different units, but I'm coming up blank on what they should be. :)
 
I must be a little dumber than usual today, because I'm going to have to ask you to explain that one to me... I assume it revolves around replacing hours and days with different units, but I'm coming up blank on what they should be. :)
Yep. There's 7x 24 hours per week, or 4.2x the 40 hour burn times the Princess can achieve on oak or locust.

The 4.7x 36 hours is for folks burning lesser woods, but we don't talk to "those" people. ;lol
 
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now now Ashful, lets not pick on the unfortunates;lol
 
I have a BK King in a 960 square foot cabin in Wisconsin, it’s average insulation and windows. I was concerned about it roasting us out, but it didn’t, it’s low setting isn’t much higher then the Princess. The heat is so controllable even if it’s 40 out I can let it run. Very happy with the BK large fire box can fill it and come back in 2 days still has coals in milder weather.
 
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It’s been said by others before, on a BK, the size of the stove is mostly just the size of your fuel tank. With their turn-down ability, it’s harder to go too large on BK.
 
And for the non cat side of the argument, I'd suggest using thermal mass to regulate the way heat is put out. Cast iron, cast iron clad, or soap stone will slow the spike of the heat released.

For the shop, you may want the quick spike of heat and a steel stove might be the answer.
 
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