Re: attic fan?
Originally Posted by maxcichon
I had the distinction of being forced to work with achitectural students on a solar concept home here on the AU campus.
Don’t get me started on architectural students & professors designing/building a solar home. There was a group ahead of me in college that did that. The end result was one of the most butt ugly homes I’ve ever seen.
Architecture in the 20th Century has manifest into a dependence on mechanical control of the indoor environment. In a sense, we have become prisoners of complicated mechanical systems. Energy efficiency doesn’t have to be difficult such as having one mechanical device to make another more efficient. All one needs to do is go back to the basics the way homes were built before we had air conditioning. Living spaces and attics were vented PASSIVELY. In general, the roof designs had louvered vents in the gables allowing air to pass through the attic horizontally.
An energy efficiently designed home will strongly relate to its site, climate, local building materials and the sun. A good example of this is the old ranch style home. The homes had big overhangs and lots of operable windows. Today, little attention is paid to the unique character of local climate and building materials.
Am I advocating that one needs to reconstruct their roof to save on energy cost? Of course not. Just exercise some common sense. An existing roof with a reasonable ridge line can easily be modified to install a ridge vent. The area of eave vents area should at a minimum equal or exceed the area of the ridge vent. Attic insulation should be kept clear from the eave vents in order to ensure airflow. Once installed, it cost nothing to adequately vent the attic.
As far as those wurlybird turbines go, they were not a bad idea when they were invented. They came out at the time we started relying on mechanical systems to cool our homes thus started closing in the attics. Then people started realizing that their attics were HOT! However, turbines are not a good idea for regions that are susceptible to heavy rain falls and/or hot summers with no breeze. If you ever stand underneath one in a heavy rainfall, guess what, you’re going to get WET! And on a hot summer day with no breeze, they are virtually worthless. To equal the ventilation a ridge vent will provide, you’d need to put them at about five feet on-center.
Now, since no one ask, let me say something about attic insulation. 
The latest in vogue thing being pushed on us is to go “green” and install cellulose insulation. Cellulose is generally made from ground newspaper. It’s then treated with chemicals to supposably make it fire retardant and resist insects. While the chemicals have been deemed safe for humans, I’m not willing to take the risk it as those chemical vapors are leaching into the living space. Paper also breaks down reducing the R-value and producing dust which also enters the living space. And, if you ever have a roof leak and don’t know it you now have a food source for black mold growing in your attic.
A much better choice is formaldehyde free fiberglass insulation. While it does break down very slowly over time, it does not share any of other the disadvantages of cellulose.
Last edited by InfernoRedXfire; Jun 21, 2009 at 12:03 PM.