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.


http://i157.photobucket.com/albums/t55/loghousenut/P1020014_zps7b4b37f8.jpg (http://s157.photobucket.com/user/loghousenut/media/P1020014_zps7b4b37f8.jpg.html)



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.

[edkemper]

The real reason the chinking doesn't necessarily make any significant difference is because of thermal mass. Heat goes to cold if or while it's "larger." The chinking stays warm because it's sandwiched between two heat sources. The little bit "extra" of heat lost by chinking's lesser R rating isn't noticed.

[eagle]

Bo, that gap is fatter than some peoples logs, you are the cat daddy!


The real reason the chinking doesn't necessarily make any significant difference is because of thermal mass. Heat goes to cold if or while it's "larger." The chinking stays warm because it's sandwiched between two heat sources. The little bit "extra" of heat lost by chinking's lesser R rating isn't noticed.
I've never heard this explained like that, makes sense.

[BoFuller]

Okay, I can't throw a water buffalo through my cracks. The biggest one was 5 inches vertically. They are 12 to 16" thick horizontally, from inside to outside.
LHN was the only one that I thought would have trouble with that.

[edkemper]

Convert to Metric?

[kh1053]

Question, I have not yet gone to the class, but found a piece of land and before I purchase I have been checking with zoning and they didn't into to much detail but said but said log homes won't meet energy requirement. I hope based upon what I have been reading in blog, that a kit might not meet but LHBA method should. I assume once through the class I should have enough building info to support the position that it will meet energy standards. Just wanted to get some feedback from everyone.

[BoFuller]

Don't buy based on your hunches. You will probably need an engineer to sign off in order to convince them.

[dvb]

Go talk to the building department. Tell them you want to buy land and build a log home, see what their reaction is. Just remember, they may sing a different song when you actually start the paperwork. Some building departments are easy to get along with, some are very difficult, (Ask Bo) and some places do not even have them.

[rreidnauer]

My bldg dept was apprehensive when I mentioned "log home" because they immediately assumed kit homes, with their inefficient skinny walls. Once I got it in their heads that I was talking about something much more substantial, they became much more receptive.

[Arrowman]

Question, I have not yet gone to the class, but found a piece of land and before I purchase I have been checking with zoning and they didn't into to much detail but said but said log homes won't meet energy requirement. I hope based upon what I have been reading in blog, that a kit might not meet but LHBA method should. I assume once through the class I should have enough building info to support the position that it will meet energy standards. Just wanted to get some feedback from everyone.

They can't stop you from building based on a suspicion you won't meet energy efficiency standards. They can, however, hold your CoO if you don't. You are allowed to build, and then show at the end of the process that your home meets the requirements. To meet energy code, you generally have to do one of two things. (1) Follow the different guidelines concern wall thickness, insulation thickness, fenstrations, etc located in the energy efficiency portion of the code before you start to build. Or (2) you can have an energy rater/engineer certify at the end of your build that your house is as energy efficient as a house that is built to the requirements.

There is free ResCheck software you can download to model your house's energy efficiency. I haven't tried modeling my house yet, but probably will over the weekend. You may not be able to get a log home to pass with the first option, but as long as its built right, you will definitely get it to pass with the second.

[panderson03]

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.


http://i157.photobucket.com/albums/t55/loghousenut/P1020014_zps7b4b37f8.jpg (http://s157.photobucket.com/user/loghousenut/media/P1020014_zps7b4b37f8.jpg.html)



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

sorta looks like she's the one doing all the work?

[Chuck G]

They can't stop you from building based on a suspicion you won't meet energy efficiency standards. They can, however, hold your CoO if you don't. You are allowed to build, and then show at the end of the process that your home meets the requirements. To meet energy code, you generally have to do one of two things. (1) Follow the different guidelines concern wall thickness, insulation thickness, fenstrations, etc located in the energy efficiency portion of the code before you start to build. Or (2) you can have an energy rater/engineer certify at the end of your build that your house is as energy efficient as a house that is built to the requirements.

There is free ResCheck software you can download to model your house's energy efficiency. I haven't tried modeling my house yet, but probably will over the weekend. You may not be able to get a log home to pass with the first option, but as long as its built right, you will definitely get it to pass with the second.

Arrowman, do you by chance recall the name of said program? :-)

[Arrowman]

ResCheck. If you google it, it should come up as a free download from a government site.

[rreidnauer]

sorta looks like she's the one doing all the work?
. . . . and now the secret is out.

[kh1053]

Arrowman , Thanks for the info, I downloaded the software, and it confirmed that my county will accept the ResCheck results, when I finally go to build, and it looks like a good tool to evaluate options you might want to consider when developing your design.

[Arrowman]

Arrowman , Thanks for the info, I downloaded the software, and it confirmed that my county will accept the ResCheck results, when I finally go to build, and it looks like a good tool to evaluate options you might want to consider when developing your design.

It is definitely useful for evaluating trade-offs in meeting the guidelines. My experience has been that really efficient windows is one of the cheapest ways to get your score up. Adding more insulation to areas like the attic, for instance going from an R-40 to an R-50 is usually one of the least efficient ways to get your score up, despite being probably the easiest to execute.