Home: Using Exhaust & Circulating Fans to Improve Air Quality While Staying Cool

Question

In the hopes of ventilating nasty odors and airborne contaminants, I recently installed the Bionaire BW2300 in one of my kitchen windows. This is the only one I have installed in my home at the moment. I leave it on 24/7 with the AC running at 82 degrees. Outside temperatures during the day hover around the 90s. So far the AC turns on and off intermittently for 5 - 10 minutes every half hour. (Trying to reduce my energy bills as well. Last month was $190.)

This morning I discovered that -- in combination with the exhaust fan -- the overall room temperature falls 2 degrees if I place a circulating fan between the short corridor that separates my living room and kitchen. I positioned it in a way that air is being pushed toward the exhaust fan.

Now my idea is to place between 1 - 3 Vornado 270s in the small corridor as well as the main hallway. The main hallway separates the living room from the three bedrooms. So it's basically t-shaped with the central AC located at the point where the "two lines of the T" intersect and form right angles.

I don't know what I'm doing, but based on my experiences so far I'm guessing it'd be beneficial to position each of these fans so that air travels from the hallway, into the living room, and then through the kitchen to the exhaust fan. That's from one end of my home (vicinity of the central AC) to the other (kitchen/patio).

So what do you think about my idea of using multiple fans to draw and force air from one end of my home to the other end? My goal is to use the exhaust fan to vent excess heat and to improve air quality.

Additional information: I have only one exhaust fan for security reasons, so I can't position a window intake/exhaust fan anywhere else. Circulating fans are fine. In addition, my family has seen a noticeable disruption in the air flow when the front door is opened (opposite end of home). The rotation of the exhaust fan's blades slows down momentarily.

Answer 1

Just a couple of points to keep in mind...

1) Any exhaust fan is moving air out of the house...that means there is outside air coming INTO the house somewhere to make up for the lost air volume. Speaking only about temperature, this could be a good thing or bad depending on where most of that air is coming in. For instance, if it is getting sucked in from your hot attic, then your exhaust fan would be making your AC work harder. If the air is mostly getting replaced by cool air from a basement or crawlspace, it might have a cooling effect on the inside of the house.

2) Humidity plays just as important a role in your comfort as does temperature. Moving the air in the house around helps your AC to take out more of the moisture in the house, making it seem cooler. Also keep in mind that your exhaust fan is sucking in outside air as mentioned above...that air may have much higher humidity than what you're blowing out...so again, the AC would have to work harder to keep you comfortable.

3) Experimentation is a GOOD THING. Ultimately it is much more important that your house feel good than to achieve some specific temperature. Just having air moving around inside can make it feel cooler than it is. So, if your efforts along that line are making you more comfortable with less AC, keep doing more of it until it doesn't continue to help.

4) before you buy more fans, check the CFM (cubic feet per minute) of air they move. Many of the smaller fans simply don't move enough air to make any difference. You mentioned "Vornado". I have one of those...couldn't blow out a birthday candle at 2 inches away. It just barely cools me down any if I have it blowing right on my face. Suggest larger fans despite the inconvenience.