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View Full Version : Passive Houses -- Engineering Homes for Nothern Climes That Do Not Require Heating


mkrishnan
Dec 28, 2008, 08:21 AM
http://www.nytimes.com/2008/12/27/world/europe/27house.html?pagewanted=all

One more from NYT... this one because it's just really cool. :eek:

DARMSTADT, Germany — From the outside, there is nothing unusual about the stylish new gray and orange row houses in the Kranichstein District, with wreaths on the doors and Christmas lights twinkling through a freezing drizzle. But these houses are part of a revolution in building design: There are no drafts, no cold tile floors, no snuggling under blankets until the furnace kicks in. There is, in fact, no furnace.

...

Architects in many countries, in attempts to meet new energy efficiency standards like the Leadership in Environmental and Energy Design standard in the United States, are designing homes with better insulation and high-efficiency appliances, as well as tapping into alternative sources of power, like solar panels and wind turbines.

The concept of the passive house, pioneered in this city of 140,000 outside Frankfurt, approaches the challenge from a different angle. Using ultrathick insulation and complex doors and windows, the architect engineers a home encased in an airtight shell, so that barely any heat escapes and barely any cold seeps in. That means a passive house can be warmed not only by the sun, but also by the heat from appliances and even from occupants’ bodies.

mcavjame
Dec 28, 2008, 08:26 AM
Talk about needing to monitor carbon monoxide.

mkrishnan
Dec 28, 2008, 11:01 AM
Talk about needing to monitor carbon monoxide.

This part is actually slightly counterintuitive. The house is hermetically sealed and heavily insulated to prevent incidental air exchange with the outside, but air is continually brought in to the house.

Decades ago, attempts at creating sealed solar-heated homes failed, because of stagnant air and mold. But new passive houses use an ingenious central ventilation system. The warm air going out passes side by side with clean, cold air coming in, exchanging heat with 90 percent efficiency.

The article states the air also passes through a HEPA filter, FWIW, in the process.

dmw007
Dec 28, 2008, 11:25 AM
Wow, that is a neat house. It is amazing how they are able to heat the house without requiring a furnace.

I am even more amazed at the cost. One would assume that it would cost a good deal more for the technology, but it fact, the cost is not that much more than a conventional house.

And in Germany, passive houses cost only about 5 to 7 percent more to build than conventional houses.

Thanks for sharing this article with us mkrishnan. :)

sushi
Dec 28, 2008, 11:36 AM
http://www.nytimes.com/2008/12/27/world/europe/27house.html?pagewanted=all

One more from NYT... this one because it's just really cool. :eek:
Interesting article. Thanks for sharing.

I found this tidbit interesting:

Most passive houses allow about 500 square feet per person, a comfortable though not expansive living space.

Here in Japan, most apartments and homes are small. This may be wonderful system for use here. Well, except they have terrible mold here. That issue would need to be solved.

trule
Dec 28, 2008, 04:39 PM
Wow, that is a neat house. It is amazing how they are able to heat the house without requiring a furnace.

I am even more amazed at the cost. One would assume that it would cost a good deal more for the technology, but it fact, the cost is not that much more than a conventional house.


There is not much technology too it. Basic concept is to take the money saved from not installing a furnace and use that money for additional insulation, high performance windows (triple glass) and a heat recovery ventilator (simple mechanical device).

Most of the "magic" comes from good design and as such is not particularly expensive, though not necessarily easy to find....

mkrishnan
Dec 28, 2008, 04:52 PM
Most of the "magic" comes from good design and as such is not particularly expensive.

The American version would clearly need a few unwarranted multitouch control panels, some laser cut aluminum alloy, vague references to nanotechnology, and a smattering of faux carbon fiber or no one would buy it. ;)

OutThere
Dec 28, 2008, 05:36 PM
Pretty awesome, however the limitation of 500 square feet/person is a bit tiny. Maybe my perceptions are just messed up though...we've got about 1400 sqft/person right now. Combo the passive-house tech with a bit of geothermal supplementary heating and you could probably do pretty well as far as expanding goes, though.

sushi
Dec 28, 2008, 06:06 PM
Pretty awesome, however the limitation of 500 square feet/person is a bit tiny. Maybe my perceptions are just messed up though...we've got about 1400 sqft/person right now. Combo the passive-house tech with a bit of geothermal supplementary heating and you could probably do pretty well as far as expanding goes, though.
I wonder what the average space per person is for the US?

I know here in Japan, it's sub 500 square feet. If I had to guess, I would say that the average in Japan is around 300 square feet.

teflon
Dec 28, 2008, 06:15 PM
It sounds like a neat idea, but I wonder, is using all those extra insulation and triple glass window less environmentally friendly than just using an electric heating system?

JG271
Dec 28, 2008, 06:18 PM
It sounds like a neat idea, but I wonder, is using all those extra insulation and triple glass window less environmentally friendly than just using an electric heating system?

True. I guess it all depends how long the house lasts for, ideally a hybrid system would be best I suppose...

PlaceofDis
Dec 28, 2008, 06:23 PM
awesome system. i wonder how the cooling is during the summer months? and just how cold the outside weather can be before having an impact on inside temperatures.

sushi
Dec 29, 2008, 12:29 AM
i wonder how the cooling is during the summer months? and just how cold the outside weather can be before having an impact on inside temperatures.
I would be interested in the answers to these two questions as well.

trule
Dec 29, 2008, 03:06 AM
awesome system. i wonder how the cooling is during the summer months? and just how cold the outside weather can be before having an impact on inside temperatures.

For cooling they have so much insulation that they often don't need any, if they do then its possible to use an "earth loop", air is brought into the house via a long pipe buried in the ground. This cools the air before it enters the building.


These houses work, with minimal heating, in climates that see 0°F (-17C).

They work by storing heat during the day from sun light (in a concrete foundation) and releasing that heat at night. So if its cloudy out then obviously heating is required, however as they are highly insulated they only need a small amount of heat, in the region 1KW, for the coldest days.

Colder than that, in the arctic circle, such houses do not work AFAIK. Its far too cold and there is not enough winter sun light. Still, the houses are built to the same standard...but when its -22 outsite the heat loss through well insulated walls and windows is significant enough to benefit from some kind of real heating.



Here is a link: http://en.wikipedia.org/wiki/Passive_house

sushi
Dec 29, 2008, 06:56 AM
For cooling they have so much insulation that they often don't need any, if they do then its possible to use an "earth loop", air is brought into the house via a long pipe buried in the ground. This cools the air before it enters the building.


These houses work, with minimal heating, in climates that see 0°F (-17C).

They work by storing heat during the day from sun light (in a concrete foundation) and releasing that heat at night. So if its cloudy out then obviously heating is required, however as they are highly insulated they only need a small amount of heat, in the region 1KW, for the coldest days.

Colder than that, in the arctic circle, such houses do not work AFAIK. Its far too cold and there is not enough winter sun light. Still, the houses are built to the same standard...but when its -22 outsite the heat loss through well insulated walls and windows is significant enough to benefit from some kind of real heating.



Here is a link: http://en.wikipedia.org/wiki/Passive_house
Cool.

Thanks for the link.

IMHO, this is a wonderful way to build homes.

velocityg4
Dec 29, 2008, 11:21 AM
One problem would be people in humid climates. You would at least need to add a dehumidifier into the system in Georgia for mid spring to mid fall. Other areas of the World are far worse in humidity.

Since these houses are hermetically sealed are they Ant proof? If so I am sold. I have always dreamed of owning an Ant proof home. Maybe a solid concrete pad surrounded by a moat.

It sounds like a neat idea, but I wonder, is using all those extra insulation and triple glass window less environmentally friendly than just using an electric heating system?

You could always build a hobbit house (http://www.simondale.net/house/). The earth is used for insulation and if their is enough earth around it the house should maintain an even temperature throughout the year. These kinds of houses are even friendlier environmentally I would assume since you do not need all of the man made insulation.

Incidentally the Hobbit House besides being environmentally friendly also looks really awesome.

mkrishnan
Dec 29, 2008, 11:25 AM
One problem would be people in humid climates. You would at least need to add a dehumidifier into the system in Georgia for mid spring to mid fall. Other areas of the World are far worse in humidity.

I think this is a really good point, but OTOH, could you imagine if, tomorrow by magic, every home in the Northern developed world, to which this technology is more readily applicable, from Russia to Northern Europe to Iceland to the Northern States and Canada were replaced with one of these? The environmental benefits would be huge.

I wonder... one thing about this design is that it takes the local needs into consideration very carefully, making it well suited to our kind of climate up here. I mean, for that matter, these houses have basements, I think, right? That itself would eliminate them from implementation in much of the South of the US. I really wonder if it would be better to take a design platform like this and re-engineer it for humid, warm climates, or if it would be smarter to start over in a place like Florida or Georgia or Greece and design a house that was suited to the climate in the first place?

teflon
Dec 29, 2008, 11:33 AM
You could always build a hobbit house (http://www.simondale.net/house/). The earth is used for insulation and if their is enough earth around it the house should maintain an even temperature throughout the year. These kinds of houses are even friendlier environmentally I would assume since you do not need all of the man made insulation.

Incidentally the Hobbit House besides being environmentally friendly also looks really awesome.

Wow the hobbit house looks pretty cool, it's like a fantastical little retreat :). Thanks for sharing! However, would it work as well on flat land? It seems to have saved a lot of material because it sits inside a hill.

trule
Dec 29, 2008, 11:54 AM
I wonder... one thing about this design is that it takes the local needs into consideration very carefully, making it well suited to our kind of climate up here. I mean, for that matter, these houses have basements, I think, right? That itself would eliminate them from implementation in much of the South of the US. I really wonder if it would be better to take a design platform like this and re-engineer it for humid, warm climates, or if it would be smarter to start over in a place like Florida or Georgia or Greece and design a house that was suited to the climate in the first place?


Don't need basements. They exist in European houses because land is so expensive that it cheaper to build down than across.

Not really intended for predominantly humid climates. Never the less there are ways to deal with that too...easiest being to move further north :D

Don't panic
Dec 29, 2008, 12:40 PM
Pretty awesome, however the limitation of 500 square feet/person is a bit tiny. Maybe my perceptions are just messed up though...we've got about 1400 sqft/person right now. Combo the passive-house tech with a bit of geothermal supplementary heating and you could probably do pretty well as far as expanding goes, though.

1400 sqft/person is a LOT of space.
in cities, it apts are way smaller than that, at least in the US.

a typical NYC 2 bedroom apartment (for a family of 3/4) is usually less than 1000 sq ft.
2000 sqft for a family of 4 is plenty of space; something along 3 bedrooms, 2 bathrooms, living room, kitchen and studio, all of reasonable size.

mkrishnan
Dec 29, 2008, 12:44 PM
1400 sqft/person is a LOT of space.
in cities, it apts are way smaller than that, at least in the US.

a typical NYC 2 bedroom apartment (for a family of 3/4) is usually less than 1000 sq ft.
2000 sq for a family of 4 is plenty of space, something along 3 bedrooms, 2 bathrooms, living room, kitchen and studio, all of reasonable size.

Yes, in cities, that is very true, albeit in suburban / rural spaces, it is generally not. I think the problem isn't so much having 2000 sq feet for 4 people (which to me is quite livable, particularly when the children are young... harder if it's a husband, wife, and two high schoolers) as it is scaling that down -- while I think 2000 sq ft for 4 is fine, I'm suffering having gone from 800 sq ft to about 600 sq ft for just myself, and I could not imagine living in 500 sq ft total. This is simply because some things don't scale down -- I still need my own bathroom and kitchen and so on.

On the other hand, I don't really understand how this is a rate limiting element of the house. If you have a person who lives by themselves in a small-moderate house or a condo (say 1500-1800 sq ft, which "should be" enough for 3 people +), then how is it any less of a gain in efficiency for that one person to move into a "passive" house of 1500 sq ft and live there by themselves? Granted, he/she would be less efficient than sharing that place with two other people, but it would still be a huge improvement over their traditional home, non?

Rodimus Prime
Dec 29, 2008, 01:30 PM
I do find it cool how the home takes advantage of the heat already there.

My appartment is very conformable when the out side temperature is between 55-65 degree as the electrics anything else generating heat tends to put enough out to keep the apartment at around 72-75 degrees.

Now cooling places like that will struggle more with internal heat generation than anything else. At a certain point like maybe 60 it might have to find a way to dump heat outside.

Mr. lax
Dec 29, 2008, 01:47 PM
These houses work, with minimal heating, in climates that see 0°F (-17C).

Not helping in Canada (even southern), it's been -45 (celsius) here (Calgary) for a while now

Sun Baked
Dec 29, 2008, 03:50 PM
Would have been funny to see a home like that with a "Heated by 2 PowerMac G5s" sign out front.

dmw007
Dec 29, 2008, 06:42 PM
Would have been funny to see a home like that with a "Heated by 2 PowerMac G5s" sign out front.

Very true! :D

When I had my 2.3GHz DP Power Mac G5, it kept my room nice and toasty (especially in summer). :cool:

mkrishnan
Dec 29, 2008, 06:44 PM
When I had my 2.3GHz DP Power Mac G5, it kept my room nice and toasty (especially in summer). :cool:

And news headline: "Excessive computer energy consumption in 'eco-friendly' homes turns them into environmental nightmares."

:D

takao
Dec 30, 2008, 02:26 PM
I wonder... one thing about this design is that it takes the local needs into consideration very carefully, making it well suited to our kind of climate up here. I mean, for that matter, these houses have basements, I think, right? That itself would eliminate them from implementation in much of the South of the US. I really wonder if it would be better to take a design platform like this and re-engineer it for humid, warm climates, or if it would be smarter to start over in a place like Florida or Georgia or Greece and design a house that was suited to the climate in the first place?

how much of rain/water do you have per year in mm in georgia ? i hardly can think that having a wet + hot climate can be a problem .. after all insulation also keeps heat outside of a building

(the only problem with a passive house is that the temperature is the same across the house which means no cooler bedroom)

mkrishnan
Dec 30, 2008, 04:09 PM
how much of rain/water do you have per year in mm in georgia ? i hardly can think that having a wet + hot climate can be a problem .. after all insulation also keeps heat outside of a building

The problem really becomes, in the US South, that 75F with air conditioning (and the humidity thereby removed) is quite tolerable, but 68 or 70F at full humidity indoors is not. When I lived in Florida, I didn't run my air conditioner hard, but I ran it intermittently for most of the summer. And in the last year, it broke down several times (grrr) and it was quite noticeable.

The other problem people have mentioned above is that there is an increased mold/fungal problem in some of these parts of the world.

I don't know if these numbers (http://www.betweenwaters.com/etc/usrain.html) are accurate, but according to them, the variance between our driest places (about 7 inches / year = 180mm) and our wettest places (Louisiana is much worse than Georgia... nearly 60 in/yr = about 1500mm) is a factor of more than eight. Per this (http://www.mapsofworld.com/cities/germany/frankfurt/), that would also be somewhere around 2.5x the rainfall in Frankfurt.

But I am not sure by any means... more my wondering was just the general idea that these homes seem well engineered for the local environment, and there is always the question of whether the same philosophy applies everywhere, or whether environmentally friendly homes should be built in harmony with the local climate. (For that matter, issues of hurricane safety, flood / monsoon safety, tornado safety, earthquake safety, etc, are all variably applicable to different locales).

takao
Dec 30, 2008, 04:39 PM
I don't know if these numbers (http://www.betweenwaters.com/etc/usrain.html) are accurate, but according to them, the variance between our driest places (about 7 inches / year = 180mm) and our wettest places (Louisiana is much worse than Georgia... nearly 60 in/yr = about 1500mm) is a factor of more than eight. Per this (http://www.mapsofworld.com/cities/germany/frankfurt/), that would also be somewhere around 2.5x the rainfall in Frankfurt.

But I am not sure by any means... more my wondering was just the general idea that these homes seem well engineered for the local environment, and there is always the question of whether the same philosophy applies everywhere, or whether environmentally friendly homes should be built in harmony with the local climate. (For that matter, issues of hurricane safety, flood / monsoon safety, tornado safety, earthquake safety, etc, are all variably applicable to different locales).

my hometown has an average of 1200mm ( from tourism info) or 1495mm (weather service) and if walk closer to the mountains it increases first to around 1900mm after 3 km and after another few kilometers into the valley its up at 2100-2500 mm and there they still have some passive houses (and they had 270mm on a single day a few years ago ..)

ah the joy of living on the northern edge of the alps... there simply is no bad weather, only bad clothes

OutThere
Dec 31, 2008, 12:20 PM
1400 sqft/person is a LOT of space.
in cities, it apts are way smaller than that, at least in the US.

a typical NYC 2 bedroom apartment (for a family of 3/4) is usually less than 1000 sq ft.
2000 sqft for a family of 4 is plenty of space; something along 3 bedrooms, 2 bathrooms, living room, kitchen and studio, all of reasonable size.

I understand it's a lot of space...that's why I was saying that having this much space may have skewed my perceptions. Where I live in Connecticut, just barely inside the limits of the New York Metro Area, my house (a late 1800s queen anne style, in town) is not particularly big...a 500sqft/person house would be rather small. It gets cold here and heating is expensive, so ultimately a house that could fit the town size-wise as well as being passive or nearly passive would be interesting to see.

AmbitiousLemon
Dec 31, 2008, 12:53 PM
I wonder what the average space per person is for the US?

I know here in Japan, it's sub 500 square feet. If I had to guess, I would say that the average in Japan is around 300 square feet.

http://books.google.com/books?id=1ixRxAsdLKwC&pg=PA121&lpg=PA121&dq=average+square+footage+per+person+united+states&source=web&ots=64lRx2VYEf&sig=R_QxJ_rlxQAVGiA4lVG8KMYA_xU&hl=en&sa=X&oi=book_result&resnum=4&ct=result
1995
Average russian: 178
average japanese: 301
poor US: 614
average US: 694

Average US (1950): 292
Average US (1970): 483
Average US (2000): 872
Average US (2006): 900

mkrishnan
Dec 31, 2008, 02:03 PM
Average US (1950): 292
Average US (1970): 483
Average US (2000): 872
Average US (2006): 900

The issue here is not only what is "livable" in whatever arbitrary sense that word is taken, but also what is economically viable. People in NYC (and Chicago) live very happily in small apartments, just like people do in London, Tokyo, and most other big cities. Our small apartments might be somewhat larger than your small apartments, but our city folk live in them happily.

If you build a 1000 sq foot independent home in a rural / suburban US setting, people will think you're crazy, not because it isn't "livable" but because isn't done. In fairness, people in those areas would have to sell a lot of their furniture and redecorate to live in a space of that size. But more to the point, you're going to need a lot more evidence of doom and gloom to get any of them to do it.

And I don't think this is just the United States. Are country homes in England not larger than flats in London?