Question about passive heating/cooling housing

[Virginia Gent]

Well first I want to say that I've done some research on this subject, but I'm far from knowledgable on everythine related to this. Second I want you all to know I am nowhere close to being able to buy land, let alone secure funds to build my own house.

However all of that may be, I figure much planning & learning can be done until such a time that I can do all of the above. This is where y'all come in, so I'm sorry that I won't be posting pictures anytime soon.

I digress, however, so let me get to my point. I love older-style housing, cabins and cottages and so forth.
http://www.countryplans.com/cowan.html
http://www.jshow.com/y2k/listings/57.html
These are some of the examples of the types of housing styles that I really like from this website. However, I also have a strong desire to have a house that heats/cools itself like with HTM Cinderblock houses and so forth. My question is, is there a way to incorperate such designs into a house that isn't made out of concret or burried in the Earth, or both?

Do Trombe Walls, Earthtubes/Earth-Cooling Tubes/Solar Chimneys really work well enough in, say, a well insulated wood-framed house that little assitance from A/C units & wood-burning Fireplaces/Stoves will be needed? And if they would be needed, what kind of Fireplace/Stove and A/C units would you all suggest that would use as little power/fuel needed to complete a comfortable temp. in a house? More specifically, I'm looking for my house to be as off-the-grid as possible. I love the idea of being as independant as possible and I have no qualms with installing solar pannels (or hiring someone to do it for me, so it's done right =p) to power these units.

One idea I had was having an overhang as a carport/garage, and putting solar pannels on the roof instead of having them sitting out in the yard or on the roof of the house itself. Is it possible to power a house and all in it with simply solar/wind/both? I have many more questions on related subjects but I'll give y'all some time to answer before I move on.

Any and all advice is welcome! Thanks again everyone!!

ED: repaired one link for greater user friendliness - MD

[MountainDon]

Much of the question, "will passive heating/cooling work for me" is dependent on the individual building site as well as the climate and even microclimate.

The main thought we gave to solar gain was to incorporate wide eves on our stick built cabin. They provide complete shade over the windows and most of the wall height on the south wall in the summer. The lower winter sun angle allows the sun to strike the window glass. We used windows with low-e glass as well.

We now have about R40 total of insulation in the ceiling. That made a world of difference over the original install of R13. (That was done as an expedient way of getting a vapor barrier up so we could install the T&G ceiling.)

So far we are quite happy with the performance of our recreational cabin.

[glenn kangiser]

We power our house with solar and wind and an occasional boost or equalization from a generator (I use a welder direct to the batteries and monitor charging as I do it)

We have 2 fridges and 2 freezers as well as pump around 600 gallons of water per day for the garden, and do a lot of welding and running various machine tools in the shop.  This post was written using solar power - stored.

[Don_P]

Passive solar requires active occupants. Usually to get the most out of passive elements you need to opne and close the shade/insulation or depending on the degree, vents. I consider our house to be solar tempered. It is south facing with a fair amount of low E glass on that side, it was southwalls mylar filmed triple wall at the time. The overhangs were tuned to shade in the summer and let the sun in 14' in the winter. That floor is an insulated slab with brown tile. West windows have the low E turned to reject the heat. I cheaped out on the doors and need to replace them at some point, they are a source of infiltration. We insulated fairly well for the time but the roof is around R30. We typically heat with about half the energy of comperable sized homes around here. I'm up in the VA mountains so we cool off at night, don't need AC.

Back in the early 70's NCSU built the McKimmon center as a solar experiment, it had a Trombe wall and they kept records on it for years. It is still there I'm pretty sure as a conference building. Inquiring of them might lead to some info. I'm pretty certain Adams Concrete products in the area provided the materials and for several years they were pushing solar concrete home designs. I remember a floor with concrete blocks laid with the web cores horizontal to form tubes under a slab poured on top. Solar hot air panels charged the mass underfoot that way.

Trying to use a thermal mass to cool is more problematic. If the mass is cool enough to work it is probably below dew point, at which point you have a large mass sweating, add any form of food and you have mold. That is the beauty of the air conditioner it passes the air over a small very cool coil. The sweating happens right there and that huimidity is extracted from the air while it is being cooled. When an AC is sized properly it runs for long periods since a large part of feeling cool is the dehumidifying part of the conditioning of the air. That said, air conditioners are mighty hard on houses. A good bit of our mold problems these past years has been AC related. Get the frame down below dew point and it sweats in contact with outside air, wood is food, hello mold. My parent's generation was frugal with AC, ours was generally set at 80. This generation sets it at 70. That opens up many more days to below dew point.

[Squirl]

Have you considered active solar?

[Virginia Gent]

I haven't heard of active solar. Is that using solar power to power objects, like an A/C unit or fridge? I shall have to do research on that.

And I would love to live in the mountains here in Va. I fancy Highland County for it's almost complete lack of people, but I'm realistic about jobs and such. I'm almost done with school to be a fire fighter, but I also enjoyed the code enforcement and fire system engineering portions of my education and have considered branching out into those fields, which would certainly give me more lean towards being in a more rural area for work.

I also spent about half my life living in Miami, so I have no problem with my house being 80 degrees. The issue is my girlfriend who is from New York; she hates warm weather and loves the cold. Virginia is probably as far south as I can move her because, here in the central Richmond area, the summers are still pretty nice. Well for me they are compared to Miami  that's why my main issue is cooling my house, with as little energy as possible.

[John Raabe]

Passive solar is about glass, mass and insulation and is designed into the building. It is an architectural solution that is very specifically customized to the climate and site. Passive techniques do not travel well and solutions that reduce utility bills at one latitude or climate can increase the same bills when done somewhere else. Passive solar can use simple inexpensive techniques that will work for the lifetime of the building. Passive solar can supplement heating and cooling but only under the most ideal site conditions will it provide anything close to all the heating and cooling energy

Active solar is about equipment and uses and makes power. It is an engineering solution and usually involves panels (such as PV), electrical power connections and/or pumps and equipment. The equipment is sized and orientated for the local sun exposure. Active solar can be added to existing buildings and is less dependent on the design of the structure. Active solar is better understood than passive and is more predicable in its outcomes.

Then there are hybrid systems that use passive techniques with things like added booster fans or pumps making them more "active".

[Squirl]

I haven't heard of active solar. Is that using solar power to power objects, like an A/C unit or fridge? I shall have to do research on that.

Not really.  Think about solar hot water heater.  Instead of dumping the heat into a coil in a hot water tank you can dump the heat into a living space through a radiator or radiant floor.  The simplest I have seen was a retrofit into an existing radiator from a steam furnace.

To the original post.  Passive solar is a function of heat gain from south facing glass during heating periods vs. loss from the rest of the house, at night, and at times when it is not sunny.  It is simple in concept but can become complicated in practice.  

I have lived and know many people that live in passive solar houses in the Appalachian mountains.  It was a popular option in the 70's during the last energy spike.  You do not need an earth bermened house for passive solar.  Although I see many people building them on this forum,  I have not met a person living in one yet.  If you are looking for a passive solar house to look like the ones you posted, you won't find that.  The problem is that they have a lot of glass on all sides.  Any window not facing within 15 degrees of south is considered more of a loss of energy than you can gain.  Think more along the lines of most or all windows south and little to no windows north, and maybe one or two east and west.  Also if you are looking for it to work, think of increasing insulation to greater than what most codes call for for electric heat in your area.  You will also always need a supplemental form of heating.

The problem with passive solar can be cooling.  I have seen people use insulated foam in decorative covers to cover windows to block sunlight in the summer.  With the rest of the house super insulated, it can stay very cool.

I would get the book The solar house : passive heating and cooling by  Daniel D. Chiras.  This was one of the better books that I read on the subject and can probably answer almost any question you have.  It can be found at most large public libraries or library exchanges.