Foo - Now that the weather is warmer, does anyone know…

Does it pay to have a fan on in a room where nobody is? I usually turn one on in the bedroom shortly after dusk and sit it near the window with the thought that it’s sucking in the cooler night air. My wife thinks I’m crazy and that the only value the fan has is to project a breeze for whoever is standing in front of it. Any thoughts on this??

Fans circulate air, but do not necessarily reduce temperatures.

From what I understand, it's a basic wind chill effect where a person will feel cooler, but the temp is the same. I'm pretty sure this applies to ceiling fans, but not sure how this applies for a box fan sitting in a window.

Rule of thumb is to turn off fans when you're not in the room to save energy.

Fans only stir the air to make it seem cooler to the occupants of the room. Turn them on when you enter, off when you leave.

The above is generally correct unless the house is specifically designed to use fans to circulate air throughout multiple rooms. A vast majority of homes are not designed this way so chances are it's more or less no real effect to having the fan on while you're not in the room. I have heard that the cost of running a normal ceiling fan is very low for a 24hr period, so I wouldn't worry too much about leaving it on vs say the oven, A/C, washer/drier, etc.

In the summer, I keep fans on at night. Windows open, air blowing in. Then during the day, window's shut tight. Cold air stays trapped indoors. Cost of running is pretty low, this fan here on my desk (somewhat small) is 96W

In the summer, I keep fans on at night. Windows open, air blowing in. Then during the day, window's shut tight. Cold air stays trapped indoors. Cost of running is pretty low, this fan here on my desk (somewhat small) is 96W
+1 When I was in grad school, I lived in a house with virtually no heat (only in the dining room) and no A/C. We did the same thing, and closed all the blinds during the day. I was the first one home in the evening, and walking into that house after walking home from campus or riding my bike home from work was almost like walking into an air-conditioned house. :D

Would turn on the ceiling fan in the living room only when in the room, just to move the relatively cool air around, and to facilitate evaporative cooling of my skin. An ice-cold beer or two from the fridge helped, too. ;)

A whole house fan is one of the best things ever. Very powerful fan that mounts in the ceiling, and sucks the air out of the house into the attic. Open some windows, and at the same time, it sucks cooler air in from outside. So nice to have in summer.

A whole house fan is one of the best things ever. Very powerful fan that mounts in the ceiling, and sucks the air out of the house into the attic. Open some windows, and at the same time, it sucks cooler air in from outside. So nice to have in summer.
+1 True dat. But where I live, gotta have really good screens or else the mosquitoes come in screamin', "Buffet!" :eek:

Does it pay to have a fan on in a room where nobody is? I usually turn one on in the bedroom shortly after dusk and sit it near the window with the thought that it’s sucking in the cooler night air. My wife thinks I’m crazy and that the only value the fan has is to project a breeze for whoever is standing in front of it. Any thoughts on this??
For the most part it works. It'll work better if you can reduce or eliminate the amount of empty space between the fan and the window. That way, you'll be pulling air in fron the outside instead of recirculating it within the room. It takes more suction than you may think to pull a lot of air across a screen. You'll also have to open up a window somewhere else in the house to create a channel of fresh air.

The way I usually do it is open up the windows in my living room. Prop the fan up, in the window in my bedroom with it forcing air OUT, and close the window around the fan. It then pulls night air in through my living room, cooling that down faster while pushing the hotter air out through my bedroom. By the time I'm ready for bed, the entire apartment is cooled off.

+1 True dat. But where I live, gotta have really good screens or else the mosquitoes come in screamin', "Buffet!" :eek:
Oh, definitely. Screens keep some of the dust and crap out, too. Houses on TV never seem to have screens, and I have a feeling that's the only place where such a thing is practical. :rolleyes:

Oh, definitely. Screens keep some of the dust and crap out, too. Houses on TV never seem to have screens, and I have a feeling that's the only place where such a thing is practical. :rolleyes:
When I lived in Belgium, we had no screens on the windows. Same in Vienna. I've seen some in Germany, but my experience there is that the mosquitoes and no-see-ums don't seem to be as pervasive or aggressive there. Go figure....

When I lived in Belgium, we had no screens on the windows. Same in Vienna. I've seen some in Germany, but my experience there is that the mosquitoes and no-see-ums don't seem to be as pervasive or aggressive there. Go figure....

Stupid Europe, ruining my assumptions! Hmph!

here's my 2 cents. In my condo, I keep one large window fan in my bedroom blowing OUTWARDS. I shut the bathroom door, And open my kitchen windows on the otherside of my condo. This creates a negetive pressure inside the house and sucks the cooler air thru the living room into the bedroom. Hot air rises, and will settle around the ceiling. By haveing continual air movement, the hot air doesn't linger. Were only talking a couple of degrees, but it works for me. Ceiling fans have foward and reverse for this reason. In the winter you put them on reverse and it sucks the warmer air down into the room. This is more practical in lofted ceilings. For the most part, fans just help the rooms not get to stuffy......

We have hot dry summer days and cool nights. No humidity to speak of. We've got 2 fans in the eastern windows upstairs and then open the windows in the rest of the place. The house is usually cool within 2-3 hours after sunset, and I'm talking AC cool. Very nice. This never worked where I grew up in Michigan.