November 13, 2007
Space conditioning without conditioners
Posted by ryan under homestead, practicalities | Tags: air conditioning, energy systems, heating, homebuilding |I spent entirely too much time this afternoon trying to figure out why our furnace wasn’t working. Was it plugged in to the wrong outlet? (No.) Was the fuse blown? (No.) Did the furnace need servicing? (No.) Was the thermostat broken? (No.) Turns out the batteries had died in the thermostat, even though it was displaying its settings just fine.
This all got me thinking, as I spent about an hour climbing up and down a ladder, removing and replacing service panels and whatnot, that our next house should have a heating and cooling system that didn’t need so much maintenance, use so much fuel (gas or electricity), didn’t dry my skin out or drench us in humidity during the summer without actually cooling… okay, a pipe dream? Maybe not.
Then I saw today’s post over at Deliberate Life. Apparently the temperature in the earth, if you dig deep enough, is a steady 50-55 degrees Fahrenheit. In colder climates, people actually put coils of fluid-filled pipes down there in a `closed loop’ system that feeds into their heat pump. That way it only has to raise the indoor temperature twenty degrees because the input temperature is higher than otherwise. How that works exactly I’m not sure, but the same notion applies for cooling too—a much more important consideration here in the oppressively hot Sonoran desert.
In New Mexico at a demonstration straw bale home, air ducts were buried some several feet down in long runs, with an intake vent at one end and outlets within the house (floor vents). They were zoned and there was some way to control the air flow in each room. Anyhoo, the house had a metal roof that would get really, really hot in the summer. A ridge vent allowed hot air to escape, so basically what happened is the air got pulled in from outside, down through the ductwork underground, where it cooled to 55 degrees. It would then get pulled up into the house, cooling the ambient temperature, and get exhausted through the roof. Indoor ambient temperature through the summer for this house rarely got above 80, and usually stayed in the mid- to high-70s, with no supplemental air conditioning whatsoever.
No motors, no electricity, no gas, no water. No appliances to maintain or replace if they break. Just good old convection. Nice.
November 14, 2007 at 6:14 pm
I’ve thought a lot about this. Though I have to admit my concern for the environment was only part of the reason. Heating and cooling air is an expensive process.
So here is my thought. What if we just decided to not allow ourselves that comfort. Or allowed ourselves less of it. Like say set the thermostat at 80-85 in the summer and 55 in the winter and turning both heater and cooler off for several months in fall and spring. I know people who wear t-shirts in winter and sweatshirts in summer to compensate for air modification. It seems like it should be the other way around.
convection would be cool though if you were building a new house and could shape it to allow the system to work. I doubt you could convert your current home to that system.
November 14, 2007 at 8:20 pm
I am totally with you on how silly it is to freeze in summer and be drenched with sweat in winter because of overactive climate control. It is like that where I work, which is an enormous facility designed with no thought whatsoever to the outdoor environment. It’s very sad because it could have been so much better with little or no extra cost… just some extra thought during the design process.
Our current home is a sort of conundrum, being a 1950s block home with evaporative cooling, single-pane windows and no insulation beyond what we’ve added in the attic on our own. In the summer at the cusp of the monsoons, when humidity and heat are both high, the cooler is working overtime to keep the house at or slightly below 85 degrees. Switching it off allows the indoor temperature to exceed 90 (what happened when our old cooler broke). That’s not very safe, but it sure costs a lot of electricity and water to run that cooler.
November 14, 2007 at 10:02 pm
Their site is being overhauled so I found it hard to navigate, but Path to Freedom is an interesting site about a family of urban homesteaders in California. Granted their climate is mild, but they did report on their choices of using no climate control aside from sweaters in winter and t-shirts in summer.
December 16, 2007 at 3:31 pm
[...] have been centered around evaporative cooling versus earth tubes, which I mentioned in an earlier post. As I’ve done more research on that subject, I find conflicting data (or no data) on their [...]