did some math on my shop btu's....

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atvalaska

Member
Jul 22, 2014
116
nenana
with what I'm heating it with now > ....1196 sq feet (10" tall to boot) 8.5 x 12' door, 2- 36"man doors and a 6'5 x 6' toy door ... 2-3x4' windows and 2- 6x4 windows,.I have a toyo 73 heating it 87% eff ...I have burned 1.94 as a minimum and 2.12 is the max "gallon per day"............ thats I have put thru her to stay warm and cozy for the last 3 years ......I come out with" 21 btu's a sq foot" to heat this building from the 15st of sept to the 1st of may ......am I doing this right??
 
That's around a 10,000 btu heat loss. Seems awfully low for Alaska. In January you only use 60 gal of oil for heat? At 1,800 sq ft in Nh I used to use around 250 for January.
 
r 30 wall........ r 6 windows.(triple pane with gas and non-metallic spacers/empd rubber seals) ..... r 18.2 doors... and a r65 roof
 
21btu x 1196sg ft =25116 btu per hr. x 24hrs = 602784btu in 24 hrs.

#1 fuel oil which is what you are getting during this time of the year contains 135000btu per gallon. At 100% efficiency that would be 4.46 gallons per 24hrs. Numbers don't look correct.
 
hummm...that is my fuel usage I filled it and measured it 2 year in a row....now my math could be wrong...but the gallons are right and I did use 135, as my number I ran my numbers like this fellow from anothersite > """
11 gallons @ 91,000 btu's/gallon = 1,001,000 btu's of fuel used
Divided by 24 hours = 41708 btu's/hr
Times 84% efficiency of the boiler = 35035 btu's/hr output
If you're heating a 3500 sq ft house with 35035 btu's/hr you're doing pretty good! That's a load of 10 btu's/sq ft ....... of course this depends on the degree day numbers from the days you were measuring the usage.""""
 
You can't argue with actual measured fuel consumption. If we take 2.1 gallons @140,000 btu / gallon as an average we wind up with 294,000btu per day.
Divide that per 24 hour day and you have 12,250 btu per hour. Factor in the 87% efficiency and your net heating load is 10,650.

Does sound low for Alyeska but there may be other factors. Any other heat sources in your garage like electrical appliances or equipment? What temperature do you maintain in there?
 
68 deg... me the wife and the dog its set up as "a house" as we build our "real house"..........I have to figure out what the house is going to take to heat ....trying to get the boiler up and running for the 1st time ....thanks to everyone for some feed back thus far.........
 
bird view of shop
 

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r 30 wall........ r 6 windows.(triple pane with gas and non-metallic spacers/empd rubber seals) ..... r 18.2 doors... and a r65 roof

This makes it make more sense. Good Job with the insulation.
 
atv...

You really need to run some heat load numbers on your house. The reason I wonder about your numbers is that we just completed our house 2 yrs ago and it missed by 1/2 point making a 6 star rating. We have r43 walls, r81 ceiling, and r20 under slab and sides of slab. Our air exchange is just over 1.3 per hr. tested with a blower door. 2688 total sq ft. 14 ft' ceilings in 1344 sq ft of the total. I used a design temp of -55f. After crunching the numbers for sizing I came up with about 11 btu per sq ft. and it is right there when it comes to heating at -50. That air infiltration is what you need to watch. Of course that is a double edged sword. Without a good HRV setup this can become a health concern quickly!
As for your shop, you have some amazing numbers! Congrats!
A great website to checkout is www.cchrc.org/ . If you are not familiar with them you should check it out when you are in Fairbanks. They are always up to something over there! LOL
 
this is my second build ...I'm going overboard on her this time ...the last house I built was 5 star ( near the end of cripple creek road)...sad chit on missing that 6th star for u ....10 grand flew away...looks like u did double wall to get 43 in the walls !............ I talk to them cold guys at uaf a few times a year...hel! I even took one of the 1st Alaska home craftsman courses in early 90! .... don't know the in's and out's of "running some heat load numbers"...but I'm learn'n this build were really going overboard on "tight" ......just getting started on my boiler set up ...big pex...I have the m-12 expansion tool ...and now a m 18 to .... with heads to 1.5 ....$$$$$$$$$$$$$$$$$....oh well this stuff is going to be right ...even if I end up poor...lol...hey !!!!....that aint funny......where do you think the air is coming into your setup ???.... maybe we should take our bs'ing to a "pm"
 
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PM would be great. Yea those guys over at cchrc always have something going on! A lot of bs at times! LOL. Our air infiltration is thru 3 bathroom exhaust fans and 2 kitchen hoods. Experience has led me to install bathroom fans in adition to and HRV as they just don't like that much moisture. Of course kitchen hoods are the other culprits. Dampers just don't completely seal. That has always been an issue that you can't engineer out.
I'm in the process now of getting our gasification boiler setup. Got my 2 LP tanks for pressurized storage the other day. One is a 1000gal and the other is an old Roy Hanson 1150 gallon LP storage tank. Doing the mods now. We are installing a Hefaistos P1, 5 section boiler. The entire system will be setup on a district heating loop. Plan on heating house plus detached shop and office. It will be next year before the project is completed.
Here's an older pic of our house (barn) while still under construction. That was about a 1 yr ago. I can safely say it's the only barn like this in Fairbanks! LOL
 
Stihly...
Thanks for the compliment. In Fairbanks you learn quickly about insulation and heat loss! LOL. Our energy cost are outrageous!!! I'm sure ATV will attest to that!
 
this is what I have for insulation high density blow in glass 2x8's 2'oc [Hearth.com] did some math on my shop btu's.... [Hearth.com] did some math on my shop btu's.... here in a shot of the kitchen window ....the vent for the kitchen sink is the only thing in the wall ...the drain stays inside the envelope AND the vent comes back in the ceiling , to hook up and exit from inside. Look close, you can see that every stud bay is calked and spray foamed EVERY seam ( I mist the bays with warm water in a garden sprayer - if makes the foam expand more = u get twice as much from a can (I use the 50$ gun) it dries harder and faster ...only works with single component btw) every plate was foamed just before standing the wall- all the electric wire holes and the penetrations into the receptacle boxes ...like building a 2700 sq aquarium...yet it can breath air to the outside with all the siding nail holes! ...it just can't move around in the bays and wash the heat from the walls BTW .....if u hit control + on your pc u can look at things up close ..even closer if u keep hitting the + sign ....>just a tip in case u suk at a pc like me lol ;)
 
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