Howdy. I have read many of the discussions on this forum and have "googled" super insulated, energy efficiency, energy efficient houses, and on and on ... I get more information that you can shake a stick at on staying warm with no furnace in Wisconsin, passive solar in Colorado, underground domes, etc., etc. But I find very little information directly applicable to the hot, humid south in terms of "optimal" construction methods (I know better than to say 'best'). I want information on the energy efficient houses in my climate. Is there one of those "seminal works" in this area? Perhaps a good web site I haven't found? Appreciate all help and information ... on this thread and a couple others I have posted recently ... although my 'southern mass' post did take on a life all it's own . Y'all take care and have a good weekend.

"hot/ humid climate" means different things to different people. Do you have an actual location in mind?

Some might call south-central Louisiana "sissy heat & humidity", but there is at least one PassiveHouse-level single-family home that has been built for that climate:

http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/following-passive-house-deep-south

To be sure that's not Gao Mali type temps, or Amazonian type humidity, but northern California or central Wisconsin it's not, eh? ;-)

Posted By Dana1 on 12 Sep 2011 04:12 PM
"hot/ humid climate" means different things to different people. Do you have an actual location in mind? ;-)

Southwest Texas ... between Austin and San Antonio (right in the middle of "hotter & drier than hell" Texas .) Admittedly, the last couple of months in the drought/heat wave have seen humidity in the teens and a couple days of single digits but that is not the norm. The humidity varies widely here diurnally, seasonally ... and yearly. East Texas might as well be Louisiana, and west Texas is the desert southwest ... and we sit in the middle. Average annual precipitation is 33 inches ... but it 'ain't' been average in a while!

Posted By Dana1 on 12 Sep 2011 04:12 PM
Some might call south-central Louisiana "sissy heat & humidity", but there is at least one PassiveHouse-level single-family home that has been built for that climate:

... sissy? that's not quite the way I remember my time at Fort Polk ... I can't seem to get a smiley to insert!

bpnkrtn is right. I also not found any..

Yeah, being a native of the Pacific Northwest I don't find south LA heat & humidity sissy stuff either. (I read somewhere that when Satan was given options of setting up in TX vs. hell, he chose the cooler weather option. :-) )

Even though relative humidity is oft reported the absolute humidity or "dew point" is really the relevant number. Dew points north of 70F is pretty sticky stuff, independent of the outdoor temp, but 75-80F dew points and 110F temps are torrid.

Key to keeping cooling energy costs low in TX is managing the solar gains through roofs & windows. CRRC rated "cool roof" finish materials & high-R attics make a difference, as does shading the windows (trees, awnings,exterior screens) and low-E heat rejection coatings on windows (even the north windows, if the landscape is mostly reflective. At code-min R using denser blown insulation (1.8lb density super-fine fiberglass, cellulose at any density) remarkably little of the heat gain is through walls, unless the siding is unusually absorptive (==dark in color.) Minimizing the total amount of window area also counts.

Air tightness is also extremely important for keeping latent loads (humidity) well bounded. Using walls and/or floors with a lot of thermal mass (adobe, concrete, etc) can even-out the daily swings in temperature & sensible cooling load, lowering the overall average energy use as well. (A fact often over-sold by those in the insulating concrete form biz.)