How to compute Stove output BTU ?

2 more splits @ 1530
15.6 lbs
up to 121.5 lbs in 18 hours.
house 72°, OAT 3°

 

3 small splits 16.6 lbs @ 1910
Should get to time for a full night load.
OAT 1°f, calm
house 73°

138.1 lbs for 24 hour heat cycle
average OAT temp say 0°f

2250 sq foot house to average 72° temperature
Go with 7600 BTU/pound this time.
1,048,800 BTUs thru the stove in 24 hours at Zero°f
80% stove efficiency
839040BTUs to the house
for 24 hours
34,960BTUs / usable heat

medium high 2.4 thermostat setting

Kept up with zero°f and have room to go higher.

3 year dry wood is noticeable better than wood I've burned in the past.
Noticeable better heat output,
cleaner burning, gets up to temp fast & lights easy

Dry wood. #1 key to good burning

 

Same thing here. No solar gain until the leaves fall. I've had a fire when it was 70 OAT.

 

No solar gain here in winter
Looks like I'll need eve more BTUs for a couple days
May have to fire up the oven for some BTU help . LOL

 

Another full load up to temp at 1030PM
Estimate 84 lbs
Stove 2.5 blower 75%
House 72°, OAT -4°, (to go to -9° )

 

House 71° after 12 hours
-15°f OAT
Stove still putting out good heat.

 

Found this
BK & others use these numbers
9,100 BTUs per pound

 

I'd like to see these calculations followed by amount of BTU's required/sqft to heat a home at avg assumptions of heat loss thru walls and ceilings as well as the change in heat loss with temperature. That might then give us all some rough numbers to figure how hard we have to run our stoves at different temps to heat our house.

 

Have seen them done by engineers. Surely there are some online.
Many assumptions,
I've seen some that measure/use "cubic feet" (air volume) for furnace/AC calculations.

I did "real world" for my "Lived in" house .
Outside doors left open, then closed when I yell "close the door, were you born in a barn "

The amount of BTUs required to heat my 30 year old, 2250 sq ft, "lived in" house, to 72° @ Zero° F outside, for 24 hours was :
138.1 lbs of Alaska birch firewood : CSS 3 years - last 2 years under roof.

No idea how many times the outside doors were open & closed letting out heat & letting in 0° or colder air, but it was several.

 

Lol...No sure what any one is saying here cause I been out having to much fun....Sorry...Not....Lol...

 

I know that today it was mid 30's here, and I barely had to have a fire to keep it at 77-78 in here. 20 degrees colder and the stove has to crank.

 

4°f .
The brief warm up for snow is done.
Forecast for 20s tomorrow, we'll see.
Above zero is nice, 20s would be even nicer.

Stove keeping up on medium fine, several less pounds of wood needed today

 

Dave how many cords a year do you average?
ETA: What kind of Birch do you burn?

 

Not enough years with the new BK cat to get a good average. (on the 3rd year)
5.5 cord 1st year of the stove, fairly mild winter
7.5 cord last year, started early, long below zero periods & long cold spell into spring.

This year , winter was late but early below zero,
less wood this year compared to last, so far.

1982 old non cat stove, I averaged 10 cord.
Better & Better wood too , this is the 1st year with 3 year seasoned & all birch, so that probably needs factored in.

 

What kind of Birch do you burn?

 

Same here, I loaded it up before work at 7:00 am and had a nice bed of coals by 4:30 pm. I just added a couple pieces at a time this evening and had the downstairs at 78-80 and the upstairs at 70-72.
I also monitor my temps during the day with a Honeywell wireless tstat I can check from my phone and it stayed warmer than it has all week today. Amazing what just 20F temp change does to heating.

 

Here's a nice website that makes it pretty simple to figure out heat loss per hour.
http://www.usboiler.net/resources/toolbox/heat-loss-calculation.php
I figured mine up to be 56,600 btu/hr lost at a 60F temperature differential.

 

Great site,
thanks

I have 6" walls, with tyvek & vinal siding on the outside ,
near 30" of blow in insulation in the ceilings
Double pane vinal slider windows , weather taped & expanding foam
Insulated metal doors. & energy rated French patio door.
Wind took out the front storm door.
2' deep, 2" blue board styro on the outside side of the foundation block.
Energy audit it rated a 4star+, I think the audit has the air leak data on it.
Need it get it out & read it again.

Still the 0° days , with high winds, a challenge to keep in the 70s

Had -20 OAT, & 72 inside.
92 degree temp difference

 

Alaska paper birch

 

We don't have any Birch. Looks like good stuff BTU wise. How does it split?