Is passive solar effective in the southern (warmer) states?

[SardonicSmile]

Most people that I see building for passive solar are living in colder climates. I am very interested in passive solar, but I live in South Carolina (a little on the warm side).

My question is.. is it even worth it to try passive solar here? I see ways to help with cold weather, but what about hot weather?

Would I use the same basic idea with low E windows facing south?

[poppy]

Sure, passive solar is effective anywhere the outside temp. is less than you want it inside.

The proplem to solve for the warmer climates is providing good enough shading the rest of the time.

It wouldn't take very many windows to get the gain you need and with enough roof overhang you can keep most of the summer gain at bay.

[MushCreek]

It might make sense to have some kind of awnings to shade the windows in the summer. Kind of the reverse of putting up storm windows! Or plant arbors with something that will lose its leaves in the winter. I'm thinking of some DIY solar hot water heat for the winter months, but it won't be fully passive.

[speedfunk]

Of course.  Lucky for you if you decide to do it you can use less extreme design strategies ( ie cheaper).  The above recommendations sound good.  Also most solar designs also involve mass so it should also help moderate your summer time highs if done right.   

[gandalfthegrey]

It works fine in southern states as well as northern. 

Look at the Earthships built in New Mexico.  They use vection to help cool during hot summer days. 
How it works is they have conduit burried under ground on the bermed up norther side of the structure and skylights in most every room.  When it starts to warm up, they pop open skylights, causing the warm air to vent upwards and draw cool air through the underground conduit.  A lot has to do with the front (southern) windows and the angle they have towards the sun also for winter heating. 

link:  http://www.earthship.net/

[gandalfthegrey]

Picture showing venting.

[dug]

I also agree that passive solar works in the South. I have lived in the Southwest for 20 years and it can get plenty cold, even in the lower elevation deserts. One point I have not seen mentioned is proper orientation. Because the sun's arc in the sky is higher during the summer and much lower in winter, it is possible to design an overhang on the roof that will block all direct sun during the summer, yet allow sun to enter in the winter. Large windows need to be facing the right way, usually real close to directly south. I experimented with the storage shed I built and it works!

[jmnpjn]

I,too live in SC and want to build around Walterboro. The answer suggesting "earthship", really appeals to me, especially the cooling aspect to help keep cooling cost down. I wonder if I can tap into the earth at about 4-5 foot without water problems. I'm from the midwest and we all had basements but I understand that is not a good option here. Solar heat, solar hot-water assist and cooling ventilation and solar light tubes might save a lot of energy costs. Also want a greenhouse to start plants in and extend growing season.
I'm on a very limited budget, low, it's almost nonexistent, but would experiment with solar energy to help run a refrigerator and computer.

[John Raabe]

In the SE you usually have moisture and high humidity to deal with in the summer (the cooling season). The cooling needs may be more energy demanding than the winter heating load. The earlier suggestions of south windows that can be shaded or insulated in the summer are good for winter time heating solutions.

If you can be assisted in the summer by increasing airflow this can be boosted by a solar chimney and by running intake air through cooler soil or the crawlspace. In dry climates (such as the SW) you can add moisture to this air with an effective cooling result. However in the SE the air may already be too moist.

Simple solutions such a white roofs, wide eaves, and siting the house to take advantage of cross ventilation from seasonal breezes are nearly zero cost cooling solutions that are often missed by modern production home builders. Do what you can with your understanding of the site and climate and then improve on this with your plantings, arbors, shade trees, etc.

Look at what was built in your area before the 1950's - before AC. Those ideas can still work. In some places the incoming air will still be too hot and/or humid for comfort -- then it's time to turn on the AC. For that, better insulation means a more efficient AC and better spent utility $$$.

[jmnpjn]

Excellent suggestions, studied the solar chimney and made sketches and it made me wonder if solar roof vents might do the same thing w/o the construction? Or possibly an attic fan drawing air from the crawl space drawing air from 200' linear buried at 4' depth pipe? Would the hot humid outside air drawn thru the clay pipes be comfortable? Would the cost be equal to an efficient A/C window unit, assuming the insulation was properly done when factoring in energy costs? ( http://www.thenaturalhome.com/earthtube.htm ) air quality?
We discovered our personal taste go for individual 97% efficient gas heaters and individual small wdo A/C over whole house hot and cold air units. In this climate the efficient electric heaters may work just as well, plus I prefer the radiant heat from a wood stove over anything else.
This is a fun site, wish I were 20 years younger. The salt box design fits what I have sketched out for years, probably go that route, younger days I would not need a plan and would go with a more fluid circular dome design.






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[cecilia]

Having lived in our home at The Duckpond through several summers now, I can see the value of building passive solar.

Here in the Yarra Valley, Victoria, Australia, we do have some very hot summers. Last year over a week of temperatures above 40C. The house faces north (don't forget we're southern hemisphere) and Jonni designed it so that from October to March we get no sun in the north side windows at all, but in mid winter the sun comes half way across the room.

Mostly even after very hot days, the nights are cooler, so we then open all the doors and windows (which have been closed all day (except for the upper clerestory windows to let out the hot air) and get a cool air flow through.

Yesterday the temperature was 38C and the house was considerably cooler than the outside. This morning, I'm sitting here with a windcheater on because it's pretty cool after the doors have been open all night.

We have wide eaves and I do notice that now the ornamental grape vine has grown almost completely over the pergola outside the northside windows, it protects the pathway directly outside the window from the sun and this has significantly increased the length of time the place stays cool.

If we get many days of extreme heat, without a great degree of night cooling, then the place does warm up, but never to such a degree that having the overhead fans going doesn't make it very bearable.

cheers
cecilia
www.duckpond-design.com.au/theduckpond

[Virginia Gent]

This site has some good ideas and is interesting. I live in Richmond, Virginia so I know all about the hot, humid summers, 'cept this year wasn't nearly that bad, and was actually quite nice in my opinion.

Anyways I digress, this site goes into HTM, High Thermal Mass, housing and it deals with heating in the winters, as well as cooling in the summers, and they claim their houses will work in any climate, well almost any. I doubt they'd work like they are supposed to in Antarctica 

SITE: http://thenaturalhome.com/passivesolar.html