Home design for wood heat.

[Realstone]

If performance is THE most critical factor and aesthetics are not, then you can't beat a monolithic dome. They are a true R60, even when it's wet & windy. They are earthquake, hurricane and tornado proof and fire & flood resistant, to the point that if one is built as an institutional building, it automatically qualifies for a FEMA disaster shelter. As for efficiency, there is a report of an Alaskan owner that claims that he didn't realize that his furnace had run out of oil for two days because it took so long to cool off. But the downside is the aesthetic appeal. Bloody igloos or flying saucers.

Here's the link


Here's a pic:

 

[LLigetfa]

Not sure of the weather in SW Idaho WRT passive solar versus Sunny New Mexico. I do see some minor gains in the shoulder seasons with passive solar up here North of the 49th but think the windows are a net heat loss overall given our cold Winters.

Something that we did consider was to use radiant floor heating in conjunction with a gas fired boiler and a wood fired boiler. In the end, the initial cost was just too high so we opted for forced air. Another consideration is what other heat source is available and what you list as the primary heat source on your home insurance. Also, if you are designing an air handling system for cooling, will it also suffice for heating? With my natural gas F/A heating, it can also accommodate cooling but it cannot be tied in to my wood heating. I had to keep the wood stove's air handling separate.

 

[precaud]

Not sure of the weather in SW Idaho WRT passive solar versus Sunny New Mexico. I do see some minor gains in the shoulder seasons with passive solar up here North of the 49th but think the windows are a net heat loss overall given our cold Winters.

Simple south-facing windows, while not to be minimized, are not considered a comprehensive passive solar implementation.

Idaho looks very good for annual solar energy availability:
http://www.nrel.gov/gis/images/map_csp_us_10km_annual_feb2009.jpg

Simply scale up in size to make up the difference.

A member of this forum, who is one of the leaders of solar energy use, lives in neighboring Montana, which has lower solar concentration than Idaho...

 

[begreen]

If performance is THE most critical factor and aesthetics are not, then you can't beat a monolithic dome. They are a true R60, even when it's wet & windy. They are earthquake, hurricane and tornado proof and fire & flood resistant, to the point that if one is built as an institutional building, it automatically qualifies for a FEMA disaster shelter. As for efficiency, there is a report of an Alaskan owner that claims that he didn't realize that his furnace had run out of oil for two days because it took so long to cool off. But the downside is the aesthetic appeal. Bloody igloos or flying saucers.

Dome homes are awesome in winter. And the space inside feels wonderful. I knew a lady that put up a pair of joined domes and was blown away with how little heat it took to stay warm in New England winters. Her biggest problem was condensation on the windows, in spite of double-glazing. This was back in the early 70s. A modern HRV would have solved the issue.

 

[Realstone]

Dome homes are awesome in winter. And the space inside feels wonderful. I knew a lady that put up a pair of joined domes and was blown away with how little heat it took to stay warm in New England winters. Her biggest problem was condensation on the windows, in spite of double-glazing. This was back in the early 70s. A modern HRV would have solved the issue.

I read that they are just as good in the summer for avoiding AC use. And yes, they do require a method of de-humidifying, something most of us the opposite problem with in the winter. I'm currently trying to convince our church to consider a dome for a new building rather than the traditional box style building.

But again, there is the look of the thing

 

[LLigetfa]

At one time I wanted to build an earth bermed house. For that one needs the right landscape to fit it into and I was eyeing up some lakefront property near here that was a challenging site because of a South facing cliff preventing access to the beach. I wanted to build into the cliff face so that one could have the garage entry level with the top of the cliff and a multi-level home hugging the face to the bottom. The wife didn't like the non-traditional home nor the notion of all the stairs. I suggested an elevator too but that went nowhere. AFAIK the property still hasn't been developed and I'd still like to take it on.

 

[wazzu]

I should add that the home will not be built in Idaho but rather in Montana at about 5500 feet elevation and in a canyon that does not lend itself to solar heating. Solar would not be cost effective anyway. I will not need AC either as it gets cold at night in the summer. I do not plan on having a central air or duct system in the house because of cost and simplicity. I should have been more clear about my needs, I have also considered the super insulation route. I do not have any need for anything other than a regular square house, no nooks, bay windows or any of that mess. Thanks for all the suggestions.

 

[jimbom]

"Efficient design for a home"? This problem we addressed when we built 20 years ago in Missouri. Our solution follows, YMMV. Sorry for the length, but we have benefited from low operating costs for very small initial investment.

Ours is 50' x 42'. First level partially underground walkout with 9' ceilings. Walls and floor insulated. Second level 10' and some 8' ceilings with 12" double stud walls and 24" deep trusses at bearing. Therefore, two feet of blown in fiberglass in attic and 12" fiberglass batts in walls. Every penetration I could find in any location in the house was sealed with foam. House is wrapped with Tyvek installed iaw manufacturers recommendations. Careful use of sill gaskets and sealing complimented by carrying the Tyvek down below the sill. Do not have a lack of humidity in the winter which indicates to me little infiltration of dry outside air.

South and east glass and overhangs maximize winter passive solar heat and minimize solar gain in summer. Minimum west and north glass. Three skylights.

Radiant floor on both levels. Work done by local general contractor using normal pea gravel concrete for second level and regular concrete for first level. Site built copper manifolds and polybutylene pipe. Not expensive. Around 3800 ft² of conditioned space. Actual measured heat load at design ΔTemp of 70°F is 23,000 BTU/hour at steady state with no solar and no wind. We have heated and provided domestic hot water with a 40 gallon natural gas water heater for 20 years except for this year. We live in a 4800 heating degree day climate. Zero degrees F is the ASHRAE winter design temperature.

So far this year we used only wood heat from a reasonably central location in "the" room. We have on the second level, an entry, living, dining, family, kitchen and breakfast in a single large room. The only other rooms on this level are four bedrooms, two baths and a laundry closet. Problem has been that every day is shoulder season. Especially if the sun is out. We have enough passive sun that stove must be allowed to go out at night or we roast. We fire the stove in the evening when inside temp drops to 72°F then run it up to 78°F. House stores and releases heat very well due to the concrete floor and heavy insulation. I circulate the unheated water in the second level floor to move the solar and wood heat from "the" room to the bedrooms. This takes a very small 80 watt pump which has used $17.41 worth of electricity since last October(Kil-a-Watt meter).

The south porch serves three functions: solar shading, wood storage, clothes drying. I stage about 2000 pounds of wood on the south porch to keep it dry and ready to burn. It hits temperatures of 70-80°F easy on cold winter days when the sun is out. This wood is a few steps from the stove. I bring every piece up sixteen steps to this porch. This will become a problem as I age. At some point, we will move to the first level and use the stove on that level. When we can no longer handle the wood, we will go back to the hot water radiant floor by turning two valves.

The east 8' wide porch is for solar shading, but has furniture and a desk where I am allowed to exist at the basest level of Ozarks man. Couch, book shelf, desk, rocking chair, beer, and even work on the chain saw at my desk. And, since the wife doesn't keep a very good eye on me, I have the naughty pleasure of letting it rip over the rail. Every few years, she asks why doesn't the grass ever grow right here. Doan no hunny is all I say. Twenty years and the boys never told on me. Good kids.

We dry our clothes on the south six foot porch. The laundry closet is handy to the kitchen and opens off the main room at the bedroom hall entrance. Total length of all hallways in the house is 20'. About the same involved in the steps between levels.

We have heavy drapes for the large glass areas, but above 7.5' on the south wall, we have windows that bring in light at ceiling level. These are not draped. Since they are under the six foot southern overhang, radiant loss to winter sky is minimal. These windows bathe the entire room in diffuse light all year even with the drapes closed. Coupled with two skylights at the north end of the big room and the east window wall, we never use artificial light during a normal day.

You can not tell from casual observation, but the utilities are concentrated at the center of the house. The kitchen, laundry, public bath, master bath, and lower level water heater and stove flue are in a central core. As is the air conditioning air handler, a horizontal unit adjacent to the kitchen in the hall ceiling. Very short plumbing runs. The main service panel is directly under the kitchen also. These are small items, but over twenty years, some little savings have accrued from not having to run the hot water very long etc. Main savings were in initial costs. Really surprising how little pipe and heavy wire is in this house.

Do overs:
- Two inches of blue board under the basement floor rather than one inch.
- Foam the sill cavity rather than 12" of fiber glass batt.
- Exterior insulation on exposed basement concrete. Still possible, but a little more difficult now.
- Originally installed a fireplace in the main room second level. Should have gone with a stove originally. What were we thinking? That has been corrected. The fireplace is gone and the stove is in place.
- Master plan for improvements that could be made over the next twenty years. A small wall penetration now when the concrete is cast costs nothing compared to doing it later.

 

[woodgeek]

Ok. Cold climate and no solar. Build super insulated and compact/simple shape with open plan. Put a big rock stove in the center. The 'super' will make passive distribution work much better, and allow the whole structure to work as storage.

 

[nate379]

The setup my folks had worked ok without power as well just from natural convection of the heat. It didn't go through the house "as well" but it still worked fine to make heat.

The only short coming of a wood furnace is when you loose power, same short coming as pellet stoves.

Nothing a generator couldn't handle. im sure if your building a new house as well set the panel up to plug in a generator. i myself would rather design around a wood stove though. interesting thread for some future ideas someday down the road.

It's nice to keep the stove and the mess in the basement instead of tracking it in the house, like I do with a stove in my living room. Plus it's nice to have the winter's suppy of wood near the stove instead of having to get it outside.

 

[dafattkidd]

It's nice to keep the stove and the mess in the basement instead of tracking it in the house, like I do with a stove in my living room. Plus it's nice to have the winter's suppy of wood near the stove instead of having to get it outside.

I agree with you here, but I like having the stove in the room I'm in the most. I really enjoy being around the fire, watching it and feeling the radiating heat.

 

[LLigetfa]

It's nice to keep the stove and the mess in the basement instead of tracking it in the house, like I do with a stove in my living room. Plus it's nice to have the winter's suppy of wood near the stove instead of having to get it outside.

I agree with you here, but I like having the stove in the room I'm in the most. I really enjoy being around the fire, watching it and feeling the radiating heat.

Put in a dumbwaiter.

http://www.woodwaiter.com/en/

 

[flyingpig]

May be this one...

http://www.youtube.com/watch?v=4dZVIBhKqWc

 

[dafattkidd]

ok, 2 things:

1. I want to live in a dome.
2. The wood waiter is hilarious, but all I want is that metal rolling cart. I love that thing.

 

[firefighterjake]

Disclaimer - Im an old house buff and biased heavily to traditional styles.

I think we could learn a lot by looking at how homes used to be built when wood was the only option for heat. Small footprint, good southern exposure, small window to wall area, low ceilings, etc. About the only thing that dosen't make sense anymore is a lot of small rooms with doors (good for heating just the in use room with fireplaces, bad for a central stove).

joutl, I think you were right on with the idea of minimizing wall to floor area... but you contradicted yourself later with the one level recommendation. Modern single story construction - ranch homes - are actually the worst deign layout in this regard. Multiple story design is much better optimized for minimizing exterior surface area, the turn of the century "American 4 square" cube is probably the ideal in this regard.

If I look back I think one of the best designs ever from a heating perspective might be the center chimney Saltbox. With proper southern exposure you have a nice wall of windows on the south side to make the most of solar gain, and that long sloping roof on the north side to give you the best protection from the prevailing northerly winds. The big central chimney puts your heat sources inside and allows you to make the most of the heat retention in all that masonry. The only update to build one today is that you might want to open up the floor plan a bit to get the heat distributed, and of course the super insulation. I would go for two smaller stove, one each floor, rather than one big one.


If I was going for central heat with wood I think I would do a boiler with storage... maybe a Garn... and in floor radiant.

Agree 100% . . . the old-timers knew what they were doing when it came to heating for all the reasons you mentioned . . . as you say the only thing I would not do today would be the small, multiple rooms that could be shut off if not in use (not so practical today when so many homes have indoor plumbing and folks tend to have much larger rooms.) I would also suggest going with super insulation . . . something they may not have had access to in the old days (just had to make do with newspaper.)

I would definitely not recommend cathedral ceilings or lofts -- I lucked out in my house when it came to heating. Low ceilings (originally I was looking for a house with a loft) . . . nearly every place I have been to that has had a loft and woodstove has had to use ceiling fans and even then it was usually hotter than Hades in the loft.

I also believe two floors is a better route than going with a more sprawling single floor with the same square footage . . . heat travels pretty easily and naturally upwards. I know the bedrooms upstairs are always the perfect temp -- not too hot and not too cold.

For most efficient . . . I would have to go with an indoor wood boiler with a heat sink capture like a Tarm with water storage device and hot water baseboard or to be even more efficient in floor heating. A masonry heater would also be another option. However, both of these options can be pretty pricey . . . if I was to build today I would go with a smaller house rather than a larger house and super insulate it . . . but otherwise it would be pretty simliar to what I have today.

 

[nate379]

Hmm, I find that single floor is better for heating. Around here it's kind of common to have "ass backward" houses where the kitchen/living room is upstairs and the bedrooms downstairs. I lived in one and it sucked. Would be 70* upstairs and barely holding 55-60* downstairs. it would get bad enough I would open the door to the attached garage and turn up the garage heater so it would warm up downstairs.

I lived in a couple 2 story houses and upstairs/downstaris would be 15-20* difference in temp.

I have catherderal ceilings in my house where the stove is and rest of the house has 9ft ceilings. I like it, makes the house feel larger than it really is. Ceiling temp is same as floor temp within a few degrees. You'll get the hot ceiling cold floor with drafts/poor insulation though.

 

[greythorn3]

low ceiling height 8' , round or octogon shape, wood stove in center, bedrooms around family room in center, kitchen by rear entry, mudroom by 2nd entry. no windows.

 

[LLigetfa]

low ceiling height 8' , round or octogon shape, wood stove in center, bedrooms around family room in center, kitchen by rear entry, mudroom by 2nd entry. no windows.

I'm guessing an outhouse and sauna are behind the woodshed?

 

[jotul8e2]

joutl, I think you were right on with the idea of minimizing wall to floor area... but you contradicted yourself later with the one level recommendation.

I certainly agree we neglect the lessons learned in some of the older house designs. And I did make one monumentally stupid statement in my post - back to that later - but this was not it. I do not recommend single level ranch style construction. My point is that given the constraints of traditional construction, the more nearly square the floorplan is the less wall area there is for a given number of sq. ft. of floor space. Certainly stacking some of the space above the floor level can bring additional efficiency. This is why my own house is a story and a half over a full basement, only about 20% wider than it is long, and has the wood burning stove almost exactly where the X drawn from the corners will meet. My objection is to mezzanine or loft construction, particularly where you are dependent upon a point source of heat such as a wood burning appliance. It is hard enough to keep temperatures within a reasonable range in such designs using high volume air handlers; without major air movement it can be unbearable.

This point is important, I think, because it is studiously ignored by architects and plan books. The old salt box houses and their near relatives were built that way for efficient use of materials, efficient use of space, and the ability to maximize the heat from fireplaces; which are, after all, point source heaters just like our standard wood burning stoves. Coupled with the thermal storage in a massive, centrally located, chimney these houses excelled in their time for comfort.

Back to my stupid statement - minimizing the wall area does not also minimize the ceiling area, which of course is simply a reflection of the floor area. It was late....

 

[chadihman]

I was really worried how the heat would move through my 2800 sq/ft cape cod home. I am amazed how the heat rises up one stairway, travels through the bed rooms and then returns the cold air back down the other stairway at the opposite end of the house. I can keep the upstairs within three deg of down stairs were the Quadra Fire 5700 is. The fan on my stove is a must and I would have two stairways on my next house.

 

[greythorn3]

low ceiling height 8' , round or octogon shape, wood stove in center, bedrooms around family room in center, kitchen by rear entry, mudroom by 2nd entry. no windows.

I'm guessing an outhouse and sauna are behind the woodshed?

the beauty of round design is you can put the bathrooms in any bedrooms its pretty much like cutting another slice of pie.could have registers in the bedroom walls facing the stove family room, also to climate control the rooms, i think it would be a very good design, the whole works could be above a underground basement where you could house your supply of ready to burn wood. and if it were a daylight basement could also be a large garage or workshop. you could even sink the center stove living room area into the basement some.

 

[barkeatr]

check out adirondack alternate energy..this fellow has created a passive solar house with a central air duct. folks plug there woodstove into areas near the central vertical duct so the house is heated by either the sun or if you live in upste NY, the woodstove.

Tim

Tim McCarthy Architect PC.

 

[barkeatr]

further on this adirondack alternate energy house plan ...here is the website.

http://www.aaepassivesolar.com/

 

[begreen]

What do you guys think an efficent design for a home would be, in order to heat with a wood stove? I am thinking 1600-2000 sq ft. possibly 2 story. Maybe someone has already done it. I find that most homes are not designed to be an efficent system, rather more of a piecemeal style put together over the years.

I stumbled upon an article today that is quite interesting. It's a net-zero home way up in Edmunton, Alberta.

http://greenedmonton.ca/blog/3

This posting on the total wood consumption should wake up a few people with poorly insulated homes. They will be heating this place with 2/3ds a cord of wood per year.

http://greenedmonton.ca/mcnzh-wood-heat-part-02

Well, that might be right in a typical year. It you read the observations, they ended up having a very, un-sunny January. Instead of their normal 92 hrs of sunshine for Jan. they had under 10 hrs total. That put a dent in the wood supply.

 

[precaud]

Very cool. We shouldn't be surprised that such a house would be subject to environmental conditions. Once they get past the novelty and measurement phase and get it dialed in, they'll just light the stove when they need to and move on with the day. But it's great that they're sharing the numbers.

This also points out what we've said in other contexts here; getting the insulation right is the main ingredient of any efficient house, and what energy you use as supplemental heat is almost a secondary concern. No matter what it is, you won't be needing much of it.