Any advice for keeping cool in hot summers?

Yeah yeah, I know it's winter. I'm planning ahead!

I'm going to be moving to Marion County in northern Arkansas, just incase anyone is familiar with the area. I'm going to have a roughly 13'x30' living space on the west end of a 30'x 60' pole barn.

The construction isn't going to be anything fancy or alternative. The living area will be well insulated, the rest will be a noninsulated workshop.

A big priority is keeping the living space cool(er) in the summer. I would prefer to minimize A/C use as much as possible. I will probably adapt to the summer heat over time, but I have definite preferences for coolth. I have no problem at all with 40-50 degree houses in the winter, but when it's 80+ in the summer I'm not too happy.

What are things I might want to take into account? If I had my way, the whole thing would be underground, but it's not my say, and will otherwise be fairly standard construction. The sidewalls of the building will be 12 or 14 ft high, and I'm presently being encouraged to have my living space in a loft. But I'm thinking it might be more important to be on the ground (with concrete floor) to have that thermal mass available. (and heating/cooling aside, I'm strongly inclined to be on or below groundfloor. I'm leaning towards it if the difference ends up being only minor). Whether in a loft or on the ground, I'm looking at a ceiling height of about 7.5' . Aside from the building itself, I have pretty much full freedom to design my living space however I please.

One idea I'm toying with: would pumping well water through some sort of radiator with a fan help? (The water would not be pumped continuously, but any time it *is* pumped, either for personal use or for garden irrigation, it would go through this. -- On the other hand, I have no idea what the temperature of the well water is, I'm just assuming it'll be relatively cold.) Or would this likely be too much trouble for a negligible effect?

I'm also figuring the roof will be painted white, and I'll probably find some means of shading it as well.

I like the creative thought but fear the energy penalty will be huge with not a lot of gain. The cooling work in your climate is more about latent/de-humidification and I dont see it drawing enough moisture out. Perhaps if one had a spare PV powered pump that had a very cool and low-head water source to draw from, it might be worth tinkering with.

I agree with the concrete slab; needed anyway for a floor, cheap and good thermal mass. Window placement(glazing type and orientation) is very important. Roof color can have worthwhile benefit. Roof design; hot roof vs cold, vented vs nonvented. Overhangs and landscaping can help.

Since youre doing AC, consider more efficient point source systems like PTAC units and mini-splits.

Most importantly, air seal like crazy.

Trees or shrubs planted on the south side of the home to block the sun but left open at the bottom to let breezes in. The idea of high ceilings is to let the hot air rise above you. An inlet low on the side of prevailing winds with an exhaust high up on the opposite side would allow maximum airflow. Neighbor installed a sprinkler on his roof that mists it during the day. Says it cut temps by a large chunk. Radiant barrier and tons of insulation if you can add more. If it gets cool enough at night, a whole house fan can exhaust all hot air at night then in the morning you close everything up.

This might be an option if you have wind exposure and better if you have dry air. Afghans in the very hot and dry western Afghanistan shove their windows full - and a few feet thick - with a dense brush (think compacted tumbleweed). They then splash water into the brush initially and then when whenever it dries. The wind blowing through it has an impressive cooling effect. Just like a swamp cooler, except the brush supplies greater surface area and thus cooling effect from evaporation. Even though they often have little water, they find it a worthwhile activity.

Too bad you don't have a say in the house design. I'm guessing Arkansas has a good deal of humidity during the summer, so swamp coolers will just seem to be mocking you in the heat. Definately block out the south facing windows, but if you watch the sun - you'll notice it only takes a small overhang to do this. The summer sun at Arkansas probably gets to like 70-80 degrees above the horizon during summer (due to the declination and latitude). You may find more direct sun will be from your eastern and western windows that will capture the morning and evening sun. Watch these sides for heat. You may find the best thing is to block them and the wall next to them out with vegetation or white paint or something. Your coolest location will probably be your north side. You can make that cooler and try some sort of convection. ... I'd like to suggest you look into passive geothermal cooling....but I'm not sure how much flexibility you have in that. There are some great ideas with using passive solar heat to assist in pulling cold air from the ground. Just a thought.

Research "Passive Annual Heat Storage" in particular materials by John Hait. While the focus is earth sheltered housing, the heat / cool storage and exchange methods of insulated earth and buried tubes should be applicable to any structure.

... I guess you wouldn't like our Arizona 120 degree summer days...

I live in SW Missouri -- I can literally see the lake that separates us from Arkansas, so the climate is pretty much identical to where you are living. (Also lived in Arkansas for about a decade. In Fayetteville.)

You will NOT be able to use evaporative cooling systems - period. Humidity is the real killer in this climate, not heat, so you may as well forget about anything along those lines. I know -- I was very determined to make something similar work here, but it really is a no go. My advice, as someone who has never used air conditioning and readily adapts to whatever temperature is out there on any given day, is to go as natural as possible. Try to learn to love heat if possible, but also wear lightweight, loose clothing (think about the white robes of desert dwellers). Use a big fan or two to move air when necessary, but also try the trick of opening the windows at night for cool air, then closing all the windows and drawing down shades to darken and shade the house during the hottest part of the day. If your insulation is good, that will keep the interior pretty cool for the best part of the day.

On a bigger, building / landscaping scale, do as some others suggest and make sure you have good plant screening on the sunny side to shade the space. (Plant deciduous shrubs and trees so you can go the opposite way in winter and get light in there when the leaves drop.) The best building solution for heat that I know of (besides living in a cave or earthbermed house) is to build a lattice about 4" to 6" from the wall on the entire south side (maybe even up and over the roof), then plant quick growing vines on it. The green cover on the outside will help to reflect heat and will keep a nice insulative, cool layer between the living wall and the structure. Then it will die back in winter to let the light back in. (Or take advantage of the insulative effect in winter too by using evergreens. Just make cutout sections around windows.) You could even have the vines do double duty as a food source if you plant peas, beans, cucumbers, etc. It's a great way to grow if you have limited garden space.

You can do the lattice and in-ground vines system easily and inexpensively using wood lattice or just wires and closed-eye screws, or you can go whole hog with a box or pipe construction that encloses the soil and water to make vertical planters -- a green wall, like some of these...

http://gardenopolis.wordpress.com/2008/06/30/growing-a-green-wall/

http://www.neutralexistence.com/begreen/green-walls/

http://www.greendiary.com/entry/gorgeous-green-walls-the-next-big-thing-in-green-building-design/

Over hangs, earth sheltering, well insulated roof, planted roof, shade trees, ponds, wind, move north.

I'm thinking of building on a concrete slap with very high insulation. I'm wondering if I could cool the house with something like the opposite of a radiative floor; pump cool water from the well through the floor and drain back to the well.

That might be too energy intensive though because I'm planning on going as off-grid as possible; not sure if a solar panel could handle a pump. Maybe I could just reserve that for the very warmest days.

Alternatively, if your setup allows, you could just run the spring water through pipes in the slab to cool it. The slab can be floor, walls, ceiling, etc. Beware of freezing, of course. Also consider condensation. If you have a situation like ours where the spring is uphill of the house you could run the spring water continuously through the pipes. From there it can run down to the livestock, gardens, etc. Our spring water is about 45°F to 50°F. I am planning to use this as one of the cooling elements in our on-farm butcher shop to remove the heat from our facility with minimal use of electricity, pumps, etc. This just uses gravity.

Cheers

-Walter
Sugar Mountain Farm
Pastured Pigs, Sheep & Kids
in the mountains of Vermont
Read about our on-farm butcher shop project:
http://SugarMtnFarm.com/butchershop
http://SugarMtnFarm.com/csa

While it may be possible in the driest of climates, you cant cool with radiant floors in the East. For those interested in heating with radiant floors, I just posted a blog entry about it; http://www.springtimehomes.com/asheville-builders-blog/?m=201201

I've read about geothermal systems that do cool by circulating cool water through the floor....

Some people use geothermal heat pumps to cool their houses here in Central Texas, but it isn't as common as coal-powered air conditioning...

I'm just trying to understand why pumping cool water through a slab floor, similar to radiant flooring but NOT radiant flooring wouldn't work according to Brian.

Apologies for not replying to you all sooner. The last few months have been busy with moving. While I'm not settled into a place in Arkansas yet, I'm close enough to start work on things and get a better sense of what I'm actually doing.

Building situation has changed. I now do indeed seem to have a say in my living space. The original building turned out to be pricier than expected, and has been scaled down. It will no longer have a permanent living space inside, just a temporary one while I work on my own place.

You all have some great ideas that I'll definitely be trying in the meantime. No western/eastern windows, shade, vines, loose breezy clothing. Thanks, it's a start!

Walter, that uphill spring sounds awesome. I wish I had a similar option, but sadly, I do not.

Since I now have some control over my housing, I've decided to go with the underground idea afterall, probably based around Mike Oehler's PSP method. I've got some questions concerning that, but I'll go post those in the underground housing thread in the green building section.

Thanks again!

Cory Arsenault wrote:I'm just trying to understand why pumping cool water through a slab floor, similar to radiant flooring but NOT radiant flooring wouldn't work according to Brian.

Humidity. Specifically the dew point. Once you get the floor to the dewpoint, it will collect condensation and the air won't get cooler until you pull all the extra water out of the air. When the dewpoint is in the 70's, it just doesn't work without creating more problems (like mold) than it solves.

IMO, there are two ways to stay cool without power--up or down. Up in a hammock so you catch breezes on all sides. Or down to the earth to connect to the cool earth, as close as you can get to cool shaded soil just like a dog digging it's bed on the shady side of the house.

Oehler/WOFATI works like the second. But like the dew point example, you need to be VERY careful with the design in humid regions. I am a fan of the PAHS earthtubes for air intakes so your air loses some of the humidity before it gets into the house, even if you don't do the rest of the umbrella.

How did the underground build go? Or what accommodation did you end up with?

Super low tech and quick is this - fill up a water bed on a concrete slab - put a sheet over the plastic so it doesn't feel icky and lay down on it - it will SUCK the heat out of you even to the dangerous point of hypothermia. Come in from outside on a hot day, maybe rinse off first and lay on the unheated water bed for about fifteen to twenty minutes; it will cool you off quickly and get you going for another couple hours. A ceiling fan on low will speed this up - having the water bed located in a stone lined structure dug back into the hill won't hurt either of course.

Check out Architecture By Synthesis - monolithic SIP structures made of two grain bins - pretty much a 20 day cooler. Or look at the plan sets on Dream Green Homes of the grain bin designs ("manufactured" category) . Of course utilizing shading, heat shields, cooling earth tubes and breezes and opening up the house at night are good adjuncts but good insulation with thermal breaks is where to start. Stone mass of course with a drain for condensation.

This topic is particularly relevant to building houses in the middle east. The summer climate in my area has average high temperatures between 42 and 48 degrees C (107 to 118 degrees F). That is not to say that we don't get hotter temperatures.

The most effective and efficient strategies I have come across are underground construction and geothermal heat pumps. Shading is important as well.