Attic fan troubles

General Questions
#1

When I moved into my house many years ago, the attic fan was broken. I replaced it and noticed a few years later that it was burned out again. I replaced that one and just noticed tonight that it to is burned out. Now I rarely go up in the attic (which is a crawl space), so I have no idea if these fans burn out after a week or after a couple of years. All of the fans have had thermostats. On the most recent fan I had it set to 110 degrees F.

Any idea why I have gone through three fans (or thermostats)? Is there a common gotcha I might be running in to? Spikey power? Flakey thermostats? Perhaps I am just overworking it at 110 F?

#2

I was checking into these things just recently - can’t remember where unfortunately but on an energy conservation website of some sort.

Their thoughts: attic fans burn out routinely because of humidity (two years is a good lifespan), that they do less for cooling your house than people think, that the wind driven turbines leak so that’s not good either, and that a couple of louvered openings to let a breeze through (and a few inches of good attic insulation) was the way to go.

#3

I was checking into these things just recently - can’t remember where unfortunately but on an energy conservation website of some sort.

Their thoughts: attic fans burn out routinely because of humidity (two years is a good lifespan), that they do less for cooling your house than people think, that the wind driven turbines leak so that’s not good either, and that a couple of louvered openings to let a breeze through (and a few inches of good attic insulation) was the way to go.

#4

I’d need a little more info on the fan to give a wAG. For example, is it gable mounted or roof mounted, what is it’s horsepower rating, what is the average attic temp in the summer (to get an idea of how long it has to run each day), etc.

In general, electric motor failures like this could be the result of bad power (high or low voltages can both cause failures), lack of ventilation leading to overheating (motor vents get clogged with dust), improper mounting putting excessive load on the motor bearings, insufficient horsepower for the application, or maybe the fan itself is just a POS and won’t last more than a year.

#5

Wow, a nonapost! You don’t see that every day.

Some of the attic fans you can buy these days have really cheap bearings in them, bronze sleeves rather than balls. Attics are dusty, and the dust can ruin a poorly sealed bearing in a year or less.

#6

I’m inclined to leave it. Unless he was on steroids, we’ll submit it for the record.

#7

Remember what happened that last time something like this occured? Someone might just use that entire post as their new username.

#8

This beats “1920s Style Death Ray.”

#9

Now it’s a 1920’s style attic fan.

#10

Thanks everyone for the help.

It is a gable fan that is mounted on the roof at a moderate angle. The attic area is pretty small compared to the fan’s advertised rating. I discovered, however, that insulation was blown into the attic and that it covered the sofit vents. I assume this is the cause – the air wasn’t moving through the attic, so the temperature stayed high and caused the fan to run all day. I replaced the fan this weekend and the attic temp was just under 120 F while the outside temperature was low to mid 80’s F. I suspect this is the source of my mold problem as well and that now that the sofits vents are clear, the attic should be in good shape. Thanks again Rhubarb.

#11

The fan is more important in getting moisture out of the attic, than keeping the living area cool. The roof will get condensation on it whaen the roof cools at night and then it drips into the insulation lay over your ceilings. You can get stains on the ceiling because of poor venting.

#12

My own experience with attic fans dying is as Squink observed, the bearings are cheap. Fans also are fitted with oil ports, such that you should put a few drops of 3-in-1 into those ports twice a year. I’m sure all diligent Dopers head to the attic spring and fall, oil can in hand. Not.

#13

How often do you lubricate your fans?

The fans in my home, be they a simple 3-speed window fan, a Hunter ceiling fan, or an attic fan, all have a small oil hole on the motor which i add a few drops of 3-in-1 oil once a month. Other electric motors around the house, such as the pumps on my well and heater also have oil holes.