Cooling a Straw House

We made some mistakes on Our Straw House. That's why this post is entitled cooling A Straw House. We'll discuss our mistakes later. In the meantime, here's some points to ponder about the cooling aspects.

Orientation

The physical location of the house is very important. Basically, aim to have the south wall slightly to the north of east. The south wall should not be parallel to an east-west line. Nope, the east end of the house ought to be 10-13 degrees north of south, so the south facing wall runs at a diagonal to the east-west latitude line.

Geometry

The house should be a rectangle with the narrowest side facing west. The idea is to minimize solar gain from the hottest part of the day. Try to avoid having any roof surfaces facing west.

Window and door openings

Avoid any openings in the west wall. Make the west wall a monolith!

Roof

Buy the biggest, thickest roof rafters you can afford---at least 2 by 10's and preferably 2 x 12's. Think THICK! Obviously, you should fill the thick roof with as much insulation as will fit.

Roof covering.

White is right. Buy the brightest, whitest metal roof you can find and that your HOA will allow.
Under NO circumstances use a dark roof. All your best laid plans will be defeated by a dark, heat-absorbing roof covering.

Roof Overhangs

You must design in overhangs which prevent the summer sun from hitting the south wall of your home. Do NOT let the sun touch your south wall. This is a huge key in cooling your house.
On Our Straw House, we designed the overhangs to prevent solar contact on the south wall during summer but allow solar input through the house during the cold winter months.

Wall coatings

Use a light colored, reflective paint on the exterior walls.

House size

Think small. The cost of everything is in proportion to the floor area of your home: property taxes, heating and cooling costs, homeowners insurance, you name it--it's all a factor of square footage. The smaller the house you can fit into, the less energy you will use and the less your cost will be.

Think seasonal

We decided Our Straw House was an invitation to go someplace cool for the summer. Hence, we became Forest Service volunteers and served 7 seasons, logging over 4,000 official hours each in volunteer capacities. For five of those summer seasons, the Forest Service put us up in rustic 1930's CCC Cabins at high, cool elevations in the middle of nowhere with trails galore every which way. Not only that, they paid our propane and water and gave us a truck to drive around in with all the gas we cared to burn. Meanwhile, it cost us NOTHING to cool Our Straw House because we weren't living in it during the hottest part of the year!

Interior design

The interior layout of the straw house ought to emphasize bright open space which highlight the undulating plastered walls and fill the house with a wonderful soft light. Avoid splitting the floor space into small rooms. Keep it open and airy. Allow for free and easy air circulation. Site your north and south doors to take advantage of the prevailing Arizona airflow current. Let those air current help cool your home.

Windows

Use plenty of windows. Bright natural light is far preferable to electric lights of any kind. Also, the larger windows enhance natural air flow. Let in as much night air as possible to cool the home as low as possible before the diurnal gain each day.

Personal cooling

We found that cooling down our own core temperatures helped modulate the "feels like" interior temperature of our home. We bought a large four foot diameter galvanized cattle tank and put it in the afternoon shade of the east side of the house. We'd go out and sist in cold water during each Happy Hour and really drop down our own core temps. You'd be amazed at the psychological difference that makes. It's very primal and it's very fun.

R Value

We left R Value to last. In many straw house discussions, R Value comes up first or near the top of the list. Yes, R Value is a VERY important factor in building a straw house. We put it last because it deserves its own blog post. R Value figures into every single aspect of living in a straw house--not just cooling. However, It's probably least important in the cooling aspect of the annual cycle of the house and that's why we put it last.

A final thought

A house/home/abode serves you 24/7/365. It doesn't just sustain you during the blazing hot daze of summer. It nurtures you 24/7/365. This is something you really need to meditate on. Nothing's perfect in this world. There's no perfect house/home/abode. Everything has its pros and cons. Overall, day in and day out throughout the annual cycle of living in a straw house, the structure performed perfectly for us. So look at the Big Picture and don't just choose a straw house simply for whatever seasonal benefits it may or may not have. There's a LOT more to living in a straw house than just the cold, dry nuts and bolts of the mathematical aspects of heating or cooling!