Chico, Sustainable

Our air conditioner is set to 81 degrees, and we are pretty happy with it. In fact, these days when I walk into a supermarket or movie theater, I feel downright chilled.

It also helps that on a typical hot Chico afternoon the temperature in our house is consistently 13-15 degrees cooler than the outside temperature, even without the air conditioner on.

Our house isn't any special icon of insulation and passive solar design. The walls have whatever insulation they were using in 1959, and the largest trees on our land are on the east side of the house, which doesn't really serve to benefit us in terms of shade (though our neighbors on that side have commented how they really appreciate our redwoods). The land immediately west of our house is a vacant, barren chunk of treeless dirt, and sadly our house sits almost right on the property line.

To make things even more fun, our exterior walls are a heat-absorbent shade of dark brown.

However, we do have three things working in our favor: Morning temperatures that are typically 30 degrees cooler than in the afternoon, a whole house fan, and R-38 insulation in our attic (blown-in recycled fiberglass).

Here is how we manage the temperature so that we stay cool in the summer while minimizing energy use:

August 31, 5 p.m. : Today the temperature hit 100 degrees outside. When I got home this afternoon, the temperature inside the house was 87 degrees, (our hottest indoor reading of the summer). Enjoying the 13 degree difference (I had just been on my bike for a 20-minute commute), I was able to turn on a ceiling fan and do chores for a half hour before turning on the air conditioner.

10:30 p.m.: The temperature finally dropped below 81 degrees, which is our signal to turn off the air conditioner, open the windows, and turn on the whole house fan. On a hot day like today the air conditioner will be on for about 4-6 hours (assuming we are home, otherwise we leave it off). Our whole house fan is on a timer, we usually set it for an hour. By the time it shuts off we are sound asleep.

6:00 a.m.: By the time the alarm goes off the temperature inside the house has dropped to 75-79 degrees, while the outside temperature is 65-70. Now is when the whole house fan is most effective. The fan pulls the warmer air from the house up into the attic, while at the same time the cool air from outside rushes in to fill the void. We have seen the temperature in the house drop as much as 5 degrees in an hour in this manner, making it both cheaper and more energy efficient than the air conditioner, which can take twice as long to achieve the same result. Generally speaking, it requires five times as much energy to run an air conditioner as it does a whole house fan.

7:45 a.m.: The last thing we do before leaving the house for day at around is turn off the whole house fan and close all the windows and blinds. This, combined with the attic insulation, helps keep the cool air in the house even as the temperature rises outside. By afternoon, the outside temperature will have climbed 30 degrees, while inside it will climb only about 10-15 degrees.

Next Steps:

--Our house has a concrete patio right by our bedroom (which has a west-facing sliding glass door), which absorbs heat during the day and takes a long time to cool off at night. We are plotting the best way to remedy this situation, through a combination of removing some or all of the concrete and replacing it with plants, adding some sort of shade structure or awning, perhaps in association with vining plants, and planting shade-giving trees (deciduous trees would be favorable, as in the winter months their bare branches would let the sun through, allowing us to save a bit on heating).

--Two of our windows are lacking sufficient blinds to keep out the sunlight.

--Though it is not cost effective to bust open the walls or floors solely to add insulation, in the event that a project does require us to expose large sections of our home, adding wall insulation will be something that we seriously consider.

--We would like to meet the owners of the land adjacent to ours (long story) to see if they might be interested in planting a tree or two (perhaps with some assistance from us) to help shade our house.

Full Disclosure: When we moved in we increased our attic insulation from R-19 to R-38 at a cost of $840 for 1680 square feet.