Attic fan questions

[ScottyP]

I am considering putting in an attic fan help cool the second floor in my house. I don't know much about them other than my parents recommending I look into getting one.

Are attic fans worth it?

Any recommended places that would install an attic fan? I don't feel comfortable installing this myself.

 

[cyhiphopp]

I think you're lost. You should go to www.atticfanatic.com.


Sorry, I have no actual input on the question.

 

[Cyclonepride]

I think you're lost. You should go to www.atticfanatic.com.


Sorry, I have no actual input on the question.

On one hand, I'm sad that this is not a real site, but on the other hand, $4888 is a goddamn steal for that domain name.

 

[cyhiphopp]

On one hand, I'm sad that this is not a real site, but on the other hand, $4888 is a goddamn steal for that domain name.

www.basementfanatics.com would be a good place for a new hok website. They can post directly from their mom's basement to BSFanatics.com!

 

[CyBri]

I am considering putting in an attic fan help cool the second floor in my house. I don't know much about them other than my parents recommending I look into getting one.

Are attic fans worth it?

Any recommended places that would install an attic fan? I don't feel comfortable installing this myself.

I don't know a lot about attic fans but have built houses. How big is the upstairs area and how many vents do you have on the roof. Maybe another vent cut in could help your problem. If you just want it cooler faster at night then I could see why you want the fan.

 

[somecyguy]

I am considering putting in an attic fan help cool the second floor in my house. I don't know much about them other than my parents recommending I look into getting one.

Are attic fans worth it?

Any recommended places that would install an attic fan? I don't feel comfortable installing this myself.

My parents house has one and it does work, but I remember as a kid, if there is a lot of humidity, it's not going to change the comfort level all that much. Otherwise, any time the temperature level outside is cool, opening a few upstairs windows and turning it on, does cool things down.

Unless you are pretty handy, I would have a professional install it so you don't worry about leaks and wiring it up.

 

[mywayorcyway]

My last house had one. Split level, 1400 sq ft. I didn't feel it ever did much. If the house was stuffy it helped clear it out. As far as temperature, I never noticed much of a change when I ran it.

 

[JayV]

Are you talking about a fan in the attic (and circulates attic air with the exterior), or a fan that blows air from the upper floor living space into the attic (and pushing the attic air out, while pulling air in through the windows)?

 

[SCyclone]

What you have to remember is that convection will drive air movement more efficiently than anything else. Check to see if the vents in the soffit (roof overhang) are open and not clogged. Correct balance between soffit vents and roof vents are key. Venting the roof nearest the peak is most efficient, as hot air tends to rise.

If you put a power vent in the attic, you will have to also add a shutter opening in between the attic and the second floor, or you will simply depressurize the attic. In my experience, the efficiency of attic fans is minimal at best.

You might also check the level of insulation in your attic.....blow-in type attic insulation, whether cellulose or spun fiberglass, is relatively inexpensive and works year round to keep air from escaping, and temperatures from getting out of hand.

 

[mapnerd]

We have one in our house that was built in 1966. We used it a little in the first few years we lived there. It was okay. However, we had a few young bats wedge themselves between the slats and get into our house. The lady of the house said that was unacceptable and so we taped it up and don't use it at all. I don't know if this helps you at all though, sorry.

 

[AgronAlum]

We have one of the whole home fans between our top floor and the attic. It was the only thing that didn’t work when we moved in and I have been debating getting it going again. It can get warm upstairs because it’s a modified split level. Any first hand suggestions on those?

Also, OP, are you talking about this

Or this

 

[Cyclones_R_GR8]

We have one of the whole home fans between our top floor and the attic. It was the only thing that didn’t work when we moved in and I have been debating getting it going again. It can get warm upstairs because it’s a modified split level. Any first hand suggestions on those?

Also, OP, are you talking about this

Or this

When I grew up we had a massive fan in one of the upstairs windows. We would turn it on and crack the other windows around the house blowing the hot air out and pulling the cooler night air in.
In the setup laid out here I would think the attic fan would work in conjunction with the air conditioning

 

[AgronAlum]

When I grew up we had a massive fan in one of the upstairs windows. We would turn it on and crack the other windows around the house blowing the hot air out and pulling the cooler night air in.
In the setup laid out here I would think the attic fan would work in conjunction with the air conditioning

It’s a 36” fan in the main hallway upstairs blowing up into the attic. I would think it would help pull the cooler air from downstairs up into the top floor. The situation you described would be what it would be used in conjunction with the AC at times when it’s too hot to open the windows. We have some issues with cooler air getting upstairs because of the split setup that we have.

 

[Cyclones_R_GR8]

It’s a 36” fan in the main hallway upstairs blowing up into the attic. I would think it would help pull the cooler air from downstairs up into the top floor. The situation you described would be what it would be used in conjunction with the AC at times when it’s too hot to open the windows. We have some issues with cooler air getting upstairs because of the split setup that we have.

I'm not an HVAC tech and don't pretend to be but a fan blowing up into the attic from the general living quarters would only seem to work with the windows open. If air is leaving it has to get pulled in from somewhere to replace it.

 

[ScottyP]

I

We have one of the whole home fans between our top floor and the attic. It was the only thing that didn’t work when we moved in and I have been debating getting it going again. It can get warm upstairs because it’s a modified split level. Any first hand suggestions on those?

Also, OP, are you talking about this

Or this

I guess I was thinking the second one.

I set up an appointment to have Mid-American do an energy audit next week so I'm hoping they can help determine if I need to add some insulation in my attic.

 

[jbhtexas]

What you have to remember is that convection will drive air movement more efficiently than anything else. Check to see if the vents in the soffit (roof overhang) are open and not clogged. Correct balance between soffit vents and roof vents are key. Venting the roof nearest the peak is most efficient, as hot air tends to rise.

If you put a power vent in the attic, you will have to also add a shutter opening in between the attic and the second floor, or you will simply depressurize the attic. In my experience, the efficiency of attic fans is minimal at best.

You might also check the level of insulation in your attic.....blow-in type attic insulation, whether cellulose or spun fiberglass, is relatively inexpensive and works year round to keep air from escaping, and temperatures from getting out of hand.

This. You really shouldn't need an attic fan if you have adequate soffit and roof vents. As mentioned, check the soffit vents; they clog up easily from dirt. Secondly, check that there wasn't something stupid done in the past, like blocking off the soffit vents with insulation (as was done in my house). Some roof designs make it very easy to block off the airflow from the soffit vents to the main attic vents with insulation.

 

[ScottyP]

What you have to remember is that convection will drive air movement more efficiently than anything else. Check to see if the vents in the soffit (roof overhang) are open and not clogged. Correct balance between soffit vents and roof vents are key. Venting the roof nearest the peak is most efficient, as hot air tends to rise.

If you put a power vent in the attic, you will have to also add a shutter opening in between the attic and the second floor, or you will simply depressurize the attic. In my experience, the efficiency of attic fans is minimal at best.

You might also check the level of insulation in your attic.....blow-in type attic insulation, whether cellulose or spun fiberglass, is relatively inexpensive and works year round to keep air from escaping, and temperatures from getting out of hand.

I will have to check the soffit vents to see if they are clogged. I haven't checked the insulation in my attic yet but will try to see if there needs to be some insulation added.

 

[Farnsworth]

I am considering putting in an attic fan help cool the second floor in my house. I don't know much about them other than my parents recommending I look into getting one.

Are attic fans worth it?

Any recommended places that would install an attic fan? I don't feel comfortable installing this myself.

The quoted just reminded me of this for some reason (at 0:25). I need to leave work.

 

[JayV]

I

I guess I was thinking the second one.

In the case of the whole house fan, my mother's house has one and it works wonders when the inside-outside temperature differentials is at least 3 degrees. Pulls a remarkable amount of air in through the windows, blows living space air into the attic, and blows attic air out through the vents to the outside. It's installed in the middle of the upstairs living area. I don't know if that location was chosen for efficiency or appearance, since it's also a hallway. I'm guessing it's about a 30-inch diameter fan. It has off-low-high speeds, and when turned on high it does make a fair bit of noise, so it's probably not appropriate for a bedroom.

As for installation, I suspect any electrician could install it if you're not feeling up to the task.

One thing she's learned since having it installed is as good as it is in the warmer months, it is a spot without insulation, so in the colder months cold air does seem to come in where it's installed. So, every spring and fall, I get the call to crawl through the attic and uncover/cover it with some fiberglass insulation pieces.

My opinion is it's very worthwhile. It's not a replacement for an air conditioner in August, but it does great this time of year and later in the fall. My own home doesn't have one and I've been considering installing one based on the results at my mom's house.

 

[DarkStar]

I

I guess I was thinking the second one.

I set up an appointment to have Mid-American do an energy audit next week so I'm hoping they can help determine if I need to add some insulation in my attic.

My understanding is that the second setup is to control humidity in the attic during the colder months. If it gets too humid during the colder months, water will condense on the inside of your roof. This leads to the growth of mold. You can tell if you are having a problem with this if your roof decking is starting to discolor.

Insulation is for keeping the house warm or cold.

Like others have said, if you have the right balance of vents, thermal driving head will give you enough air circulation to control humidity and you should not need a power vent. But, if you do not have good circulation, it is a cheap bandaid solution you can try to mitigate the problem until you replace the roof. Typically after the next big hailstorm comes along and insurance pays to replace everything.