Monday, September 10, 2012

View from Our Sustainable Cabin

Since we've been focusing on selling our house, we have not spent as much time on our cabin lately, but we are still moving forward with the construction of our sustainable cabin.  It takes much more planning and time to build in a sustainable way, but we are glad we have stuck with our plan/design for a cabin that will use natural cooling methods as much as possible.  We are seeing these methods work already and the cabin isn't even insulated yet.  

When you bet your sustainability on the facts that heat rises and water flows downhill, you will always win.  That's what we are betting on!

Here is a recent pic and a video.   The video shows the view from the breezeway, but not the actual cabin itself.  I never tire of this gorgeous view.  I love having my breakfast and morning prayer from this spot.



sustainable design feature: Breezeway
One of the design features that make this cabin sustainable is the breezeway.  

With the beautiful view, we wanted a covered area to allow us to spend more time outdoor.  A breezeway is like a porch because it is covered, and that is important to us because it is really hot here in summer, but also important because my skin is so sensitive to the sun.  A breezeway that faces the south gives us another great advantage; it allows the breezes from the south to pass next to the house, carrying away hot air.  This can be especially effective when the breezeway has a stone or concrete floor and when the breezeway is flanked on East and West side to block direct sun during the hottest part of the year.  

Sometimes here in Texas you will hear the old-timers call this a dog run, because if you have a dog and a breezeway, you will find the dog laying in the shady breezeway, enjoying a snooze, during the hottest part of the day.  Smart animals.

Another sustainable design feature is to install ceiling fans made to run on small solar PV panels.  While these do not store energy for use at night, they are relatively inexpensive and will be very helpful in the afternoon when the breeze patterns change.  All animals produce some amount of heat.  When wind blows on a person, it removes the heat that builds up and surrounds the person. This type of heat building up is called a heat envelope. By removing the heat envelope, a person can feel much cooler.


for more information about heat envelopes, sun orientation, natural heating and cooling, and other passive solar designs concepts, check out this post from Jan 2010.  Passive Solar Design Concepts


sustainable design feature: Window Placement
Another sustainable design feature in our sustainable cabin is the thoughtful placement of windows. Yes they are thoughtfully placed to capture the view (see video above), but even more so they were placed based on sun orientation and the changing seasons. The roof overhangs the front of the building by 5 feet.  The windows on the front (south facing) side are 3 feet off the ground.  In the hottest part of the scorching summer, the sun barely hits the house at all.  See, there is a reason to use geometry after high school!  :) 

See the shade line in these two different photos?  

This pic taken first weekend of Sept.  
The cabin is in the shade during the summer. 

This pic taken in Feb.
The cabin absorbs heat from the sun during the winter.


sustainable design feature: Green Plants irrigated with Grey Water
Once we have running water, we will discharge grey water into a garden bed in front of these windows. Even a small patch of greenery near the foundation can cut out a portion of the heat absorbed into the foundation.  

for more information about grey water, 
see our previous post: Ideas for using Grey Water.


Here's how it works: 
  • When green plants cover the ground, it turns light into energy, thus reducing the amount of light/heat that the rocky ground can reflect back onto the house. (Elimination of natural heat reflection.)  
  • It also reduces the amount of heat that builds up in the soil (Reduction of solar heat buildup)
  • When green plants are exposed to heat, sun, and wind, they release moisture.  In an arid environment, that moisture will evaporate, causing the air to cool.  (Natural evaporative cooling, this is why a fine mist of water  in summer feels good in Arizona, but does not feel good in Louisiana where the air is already overly humid.)

Overall, that equates to a cooler house and less energy on cooling.  Those are some sustainable solutions!