Energy efficiency

[beatgeek]

I'm trying to get a realistic idea of how energy efficient log homes are. I understand they use thermal mass more than insulation. For those of you who have already built log homes, what is your heat source in the winter? If you use a woodstove or masonry stove, how many cords of wood do you use each winter? (and describe the size of your home, to get a sense of scale)
Is any cooling necessary, for those of you who live in areas with hot summers?

[loghousenut]

I can't answer your question but I can pass along what I have learned. Skip Ellsworth (the Ole Man) used to say "You'll never be too hot or too cold in a properly built log home". My limited experience seems not to contradict his sentiments.

We (the Nut family) are currently building a LHBA style log home in the hottest corner of Oregon and have foolishly provided no provisions for air conditioning. Current best estimate for moving in is 12-20-2017. I think we will be fine with no electric cooling, though all of our neighbors have AC built into their stick homes. You are correct, it is all in the thermal mass thing. Bigger logs means more comfort. It takes a while to get these things warm (or cool) but they stay that way easily. That is one of the reasons we (LHBA members) do it this way.

Just don't go to thinking that a 6" thick kit house wall will do the trick. Bigger is better.






She hates this photo.... It looks just like her.

[eagle]

I've seen that look before on my wife, usually when I did something wrong. I was curious as well, I understand the thermal mass thing but if you have fairly large gaps to fill, doesn't that take away from that since that area is only a few inches thick?

[Timberwolf]

Cement chinking (backed by insulation of course) has plenty of thermal mass as well.

[rocklock]

I must have answered this question at least 5 times.. so here is #6.
My log home is 31 by 31 by 34... A cube with a walk out basement. I heat with God's fuel, wood. It's amazing. The wind blows, trees rub against each other and stuff comes down... We use about 4 to 5 cords each year. We also use electric and gas in spots... Some time in the future we will use the coils in the cement with hot water... When we get too old to chop wood.

I have a ton of insulation between my logs as well as mortar chinking and more stuff that is taught in class that assists in infiltration and the moister control.

As I have explained many times, because of my great room, and the rise of hot air I have about a 7 degree difference in temp between floors. If I am too hot I go down, too cold - go up. Several years ago when Seattle was about in triple digits, I lived in my basement during the hot part of the day. It was 68 degrees in my basement. I have a sort of thermal Chimney for my second floor so it there is cool air around I can take advantage of it.

I would use a Masonry Stove if I did this again. We have a home on Camano that has an internal fireplace that was built with about 30 tons of rock. It acts much like a Masonry Stove. It heats the entire home with a very small fire... Thermal mass again.

I also have a single fan that moves the hot air around... ie I can move the hot air from the second floor to the first if needed or reverse the fan to assist the thermal chimney.

All in all, my log home is extremely efficient. OBTW, my guest room is generally heated with a single electric heater. It is in two ICF's wall with r-20 insulation and half covered with dirt. Pop on the heater for 45 min and the temp will stay that way for 4 hours.

See the photos below as well as the videos.

[BoFuller]

I was curious as well, I understand the thermal mass thing but if you have fairly large gaps to fill, doesn't that take away from that since that area is only a few inches thick?

My logs average 24 to 26" in diameter. The gaps are at least 12 to 16" thick. Chinking, insulation, insulation, and chinking.
It was cool this summer when we hit 100 a few times, and it's warm in the winter. We sometimes open the windows upstairs when the fire has been too hot.

[loghousenut]

My logs average 24 to 26" in diameter. The gaps are at least 12 to 16" thick. Chinking, insulation, insulation, and chinking.
.

If everyone else reads this like I read it the first four times... Oh, never mind.




It seemed at first like you was bragging about your cat-throughs.

[donjuedo]

Sure. Bo throws bigger cats, too.

[donjuedo]

It was cool this summer when we hit 100 a few times, and it's warm in the winter. We sometimes open the windows upstairs when the fire has been too hot.

Cool when 100 outside is impressive.

[dvb]

We have a 24'x24' two story house in the Colorado mountains. Temps below zero are common in December, January and February. We had -34 F just the other day. Last winter we were gone all winter on business and we left the house thermostat at 50 F to keep things from freezing. We heat with propane when we are not here to maintain a fire, we burned 375 gallons of propane from October 2014 until August 2015. I think you will find that the logs will not be where your heat loss is, it will be in how well you insulate the Gable ends and the ceiling/roof. Also what quality of windows you install will make a significant difference in your ability to heat and cool a house.