The life of a “Modman.â€

Now I realize that there are allergies to worry about as well as other outdoor contaminents, but when the outside air drops to a temperature lower than your desired thermostat setpoint, open the windows.

Yeah yeah, I know how obvious this sounds, but it's amazing how many people simply don't do it. Opening the window and using small fans is more efficient than boxing yourself in and using the A/C. Also, the air doesn't have to move much. People often believe that if they can't feel the air moving, there's no movement at all. In reality, even a little bit of movement is enough to remove moisture from the skin which is how we sense cooling. So open windows on opposite walls (north and south, for example) and let the air move all the way through the house.

Additionally, you have to keep in mind that a fan works by moving air from one place to another. This means that to work efficiently, it must have somewhere to get the air and somewhere to put the air. So putting a fan in a window of a closed room accomplishes nothing. For efficient fan useage, make sure a window and door are open so the fan can pull air from one place and push it somewhere else. Again, sounds obvious when you hear it but I see it all the time.

Now that I'm in HVAC mode, here's an interesting chart showing the comfort level for human occupation. Don't bother with "dry bulb" just think "temperature". You can see that there's a variance in the relative humidity depending on the ambient temperature. There are many things at work here. For example, dry air will dissipate heat quickly because there's nothing in the air to retain it. This is often why it's so hard to heat a cold, dry house. By introducing humidity into the air (within reason: 30% - 80%) you will retain the heat in the air and require less mechanical heating thus saving fuel and money. On the other hand, notice how in the summer you want to bring the humidity down to about 20% - 60% because if it's hot and humid, you'll be miserable and therefore crank up the A/C. Many people fail to put relative humidity in the equation of personal comfort.

 

TJ's right on a few levels there. While I like to be green and conserve, not everyone's all gun-ho and there is a point of reality that kicks in. I would like to put my TV and things on a timer so that I don't have to reach over and unplug them. Unfortunately, some days I work from home and some days my wife is home and then it's just awkward.

Everyone has a carbon footprint whether we like it or not. I think that the goal should be to reduce our footprint wwithin reason. I believe that's one of the key elements in convincing other people to be green: not forcing them to compromise. That's how this thread started, afterall.

 

I had no idea these exist! Excellent.

In case you're curious, the evaporation part works on the same principal as industrial Cooling Tower in which water is used to wisk away heat and cool the pipes before they re-enter the building. Notice the three shower-head-looking sprayers at the top of the attachment. Exact same principal. I'm telling you all this as a psuedo-expert endorsement for the technique showing that it's tried and true.

Also, while digging around for the Cooling Tower image, I found this other one. I mentioned above that the fans don't have to be running full-bore to cool the space. I've also attached a graph known as the "Fan Curve." It shows that if you can slow a fan down (bottom of the graph), you are greatly reducing its energy draw (left axis). In residential settings, this means use the lower speeds. For commercial settings, the fans are often variable and they ride up and down this curve as the need requires. Of course, we aim to keep the speed low.