Amy Gahran

The main level of my home has LOTS of windows — all inefficient.

Earlier I wrote about my home’s new attic fan, which (so far this summer) is doing a much better job of keeping my home cool than the aging central air conditioning unit ever did. I am running it during most of the day, however.

Jay Stein of E Source pointed out that this is not an ideal practice. He commented: “You’re not supposed to run the fan all day long. Just run it at night, when it’s cool out. Be sure all the windows are open. Get the house nice and cold. Then in the morning, shut all the windows and pull down all the blinds. Your house should stay cool until the late afternoon. When the evening rolls around, open all the windows and start over again.”

Jay’s absolutely right; that is recommended practice for using an attic fan. However, our house has some significant flaws which — as far as I can tell — require some compensation as we work to correct them one at a time. Right now, running our attic fan during the day, instead of our central air conditioning, is an intermediate step toward efficiency, and an immediate step toward comfort.

In the summer, cooling our home at night has never been a problem. Our home faces west-east, the same direction as Boulder’s prevailing wind patterns. So if we open all the upstairs windows after sunset and run the bedroom ceiling fan we almost always pull a steady cross-breeze through the house that sucks out the day’s accumulated heat. So we don’t really need an attic fan for traditional reasons. It has more to do with compensating for our home’s serious daytime cooling flaws.

Plus, I personally prefer moving air far more than cooled air. I’m more comfortable in dry, moving air. I’d rather avoid air conditioning if I can — I had more than enough of it when I lived on the east coast. I don’t enjoy feeling like I’m living in a refrigerator.

Making tradeoff decisions when upgrading a home’s comfort and energy efficiency is something many Boulderites face. Much of the housing stock in town is decades old and was built by developers who apparently cared more about construction speed and profit margins than energy efficiency.

Here’s how we’re handling those decisions in our own case…

WINDOW REPLACEMENT

One thing I love about my home is its ample daylighting. We’ve got lots of windows, especially in the living/dining room (see photo above). Unfortunately, they’re old aluminum-frame windows, and they offer poor insulation. Replacing them all probably would be the best thing we could do to enhance the comfort and energy efficiency of our home. However, that’s a big, complicated, costly project we cannot undertake this year.

Amy Gahran

The new efficient windows we installed in our master bedroom are a huge improvement for comfort.

Last year we did replace our master bedroom windows with vinyl-frame, low-E glass models, and that did wonders to improve the comfort of that room — especially in winter. We felt that was necessary because our master bedroom sits over an unheated storage loft, which is above an unheated garage. Since our forced-air heating system never worked well, the bedroom often was freezing in the winter. Simply putting in more efficient windows has made a huge difference in that space.

We do plan to upgrade all of our windows, probably next year. In the meantime, we needed a way to effectively cool our home in the summer — especially during the day on either/both the main or upper levels, since I work at home.

Right now, thanks in part to our less-than-ideal windows, we get major solar gain on the eastern (back) side of our home from early morning through early afternoon — prime working hours for me. As I mentioned earlier, thanks to Boulder’s dry climate I’m comfortable enough to work as long as the air around me is moving even slightly. Hence, I find that opening a shaded basement window, keeping all other windows closed, and running the attic fan during the day keeps my home far more comfortable than running my air conditioner ever did.

WINDOW TREATMENTS

We probably could improve the comfort of the home, and run the attic fan less, with better window treatments (drapes or blinds) on our main level, where we get most of the solar gain.

We’re looking at options for that — but we need to find something that our active cats won’t destroy (as they did with most of our original blinds) and that won’t make the space too dark. I find I work and feel best in ample natural ambient light — which I why I don’t have my office in our basement, it’s too dark down there for me to work all the time.

We’ll probably install new window treatments on the main level as soon as we can find an appropriate, cost-effective option. (Suggestions welcome, please comment below.)

HEATING AND COOLING

Tom Vilot

Our old, inefficient central air unit — destined for the trash heap, hopefully next year.

Our house was built in 1989, and still has the original exterior central cooling unit and forced-air system. They’re old and inefficient, and they weren’t top-of-the-line to begin with. Our heat works well in the winter, but in the summer our cooling is poor and unreliable, especially during the hottest part of the day.

Frankly, we’d like to replace both pieces of equipment — but we want to be smart about it. This year we’re just trying to keep our house cool enough at an acceptable energy cost. Next year, we hope to replace our windows and then get an ultra-efficient new cooling unit and heating system appropriately sized for our home’s updated requirements.

VENTILATION

Ducts are an issue. We do plan to get our ducts cleaned this year, maybe even this summer. That will probably help with air circulation when we run the forced-air system. The forced-air system does have a fan-only setting.

The bigger problem is that our vents are in the wrong places for effective cooling. Given the layout of our house I suspect it would be cost-prohibitive to try to relocate our ventilation ducts so our vents are positioned more effectively. They’re on the ceiling only in the basement, and in the floor at the edges of rooms through the rest of the house. That works well enough for winter heating, but it’s exactly the opposite of what works best for summertime cooling. I’m sure it was much less expensive for the developer to build our house that way — but the developer doesn’t have to live with the effects of that choice.

So aside from cleaning the ducts and changing the HVAC air filter regularly, I don’t know that there’s much else (aside from the attic fan) that we can do for ventilation.

We are considering adding more ceiling fans (on the main level, and in my office upstairs), but we want to see first the effects of replacing our windows next year. That might be enough.

GOT A BETTER IDEA?

…That’s our current thinking for upgrading our home’s comfort and energy efficiency. Like most Boulderites, our home represents the lion’s share of our energy consumption, so we figured that’s where we’ll spend our money. In addition to energy and cost savings, we’ll reap the benefits of increasing the value of our home through upgrades, and enhancing our comfort.

Of course, we can’t afford to do everything at once, so we need to make decisions about tradeoffs and intermediate measures.

We are about to schedule an energy audit of our home, and we’ll blog the results and recommendations of that. But in the meantime, if you have any critiques of our plans, or suggestions, please comment below!

Thanks, Jay, for raising such an important issue.

This entry was posted on Wednesday, July 4th, 2007 at 5:21 pm and is filed under Buildings, Choices & actions, Residential, Your stories. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.