power attic vent fans

[Quadforce]

Hey just curious what you guys set your fans to in the attic.. I just had some put in a couple months ago and the guy set temps at 90 but I am kind of thinking they will run 24 hrs a day like that right now do they need to go up to 105 or something ??

[Samhain]

Hey just curious what you guys set your fans to in the attic.. I just had some put in a couple months ago and the guy set temps at 90 but I am kind of thinking they will run 24 hrs a day like that right now do they need to go up to 105 or something ??

Mine are set for 120 to 130.

[idrivea4banger]

How helpful are these with keeping heat levels down and keeping the AC unit from running so long?

[Quadforce]

I had mine put in and with in a half a month i noticed a difference in bills. they were installed mid month 2 months prior it was like 1140 kwH used and the next month 1180 and then after half month it was 940

[Sgt Beavis]

I put in a solar powered fan about 6 years ago and my electric bill dropped about 20 bucks a month. More importantly, it felt like the house was a bit cooler. The upside is that you don't need an electrician or AC guy to install them. The downside, with mine, is that I have to go up in the attic every fall and spring to turn it off and on. Not really a big deal. I'm betting the newer ones have a thermostat.

[dcs13]

I have the power version as well. HAd a very reputable A/C guy work on my unit last month. He said they're a waste of money and to install a good whirly bird type instead. fwiw

[ceyko]

I have the power version as well. HAd a very reputable A/C guy work on my unit last month. He said they're a waste of money and to install a good whirly bird type instead. fwiw

I really think this depends on a bunch of situations and I also feel like it would require 2-3 whirlybirds compared to 1 powered one since they are passive. Plus, IMO the powered ones have a better appearance.

To the OP, we kept ours set pretty high. That way it did not run when cool-enough out, but the moment it was hot it was running. 110-120 should be fine. At 90, that fan is probably running when it's sunny out but 75 degrees.

[mikec]

I really think this depends on a bunch of situations and I also feel like it would require 2-3 whirlybirds compared to 1 powered one since they are passive. Plus, IMO the powered ones have a better appearance.

To the OP, we kept ours set pretty high. That way it did not run when cool-enough out, but the moment it was hot it was running. 110-120 should be fine. At 90, that fan is probably running when it's sunny out but 75 degrees.

If you look into the numbers involved with how much air is moved the turbines win hands down. As for passive, heat rises, generating motion, at which point they aren't really passive. They're mechanical, and very efficient.

The solar and powered vents are not nearly as efficient, but do work. Get up in the attic with the solar powered ones and you can almost count the revolutions. Hilarious considering the cost. The electric ones can have a chinese produced thermostat malfunction pretty easily and then not work at all.

[bcoop]

If you look into the numbers involved with how much air is moved the turbines win hands down. As for passive, heat rises, generating motion, at which point they aren't really passive. They're mechanical, and very efficient.

The solar and powered vents are not nearly as efficient, but do work. Get up in the attic with the solar powered ones and you can almost count the revolutions. Hilarious considering the cost. The electric ones can have a chinese produced thermostat malfunction pretty easily and then not work at all.

Why is it that roof guys always claim they are snake oil, but HVAC guys and homeowners that have them swear by them? Not a knock, genuinely asking. I've talked to several roofers with the same opinion as you, and I've talked to several HVAC people and homeowners who made the switch, and they all love them and see an immediate savings?

It should also be pointed out that the effectiveness of the whirly birds is ENTIRELY dependent on the correct amount of soffit vents (I've noticed a lot of newer homes, and tract homes in general, don't have near enough) , and those vents being free from obstruction of airflow.

[blownaltered]

Why is it that roof guys always claim they are snake oil, but HVAC guys and homeowners that have them swear by them? Not a knock, genuinely asking. I've talked to several roofers with the same opinion as you, and I've talked to several HVAC people and homeowners who made the switch, and they all love them and see an immediate savings?

It should also be pointed out that the effectiveness of the whirly birds is ENTIRELY dependent on the correct amount of soffit vents (I've noticed a lot of newer homes, and tract homes in general, don't have near enough) , and those vents being free from obstruction of airflow.

Because hvac guys don't know anything about roof ventilation and they don't have to replace the damn things all the time. Yeah homeowners love them at first but then replace them with something else when they reroof their roof because they haven't worked in years. I hardly ever put power vents back on a house because the homeowners are tired of replacing them. Experience is why roofers hate them, inexperience is why everyone else likes them.

[bcoop]

Because hvac guys don't know anything about roof ventilation

I'd say that's pretty arrogant and inaccurate, but maybe that's just me perceiving how you worded your response. Any HVAC guy worth his weight should know plenty about roof ventilation, because it affects heat loads.

I'm not saying a lot of them don't, but I'd think the good ones do. Sounds to me like another pissing contest between trades that are all too common, unfortunately. At any rate, I'm switching to power vents. My whirly birds hardly move, and if I can reduce attic temps 20+ degrees like I've seen happen with friends, I'm all over it. Whirly birds usually have to be replaced after a heavy hail storm anyways, which could mean yearly in a lot of cases in NTX.

[Quadforce]

mine have a 1 year warranty parts and labor and I think 5 year for just parts. I did have one motor go out and company sent me a new one that was twice the size free had it in couple days. It was a pita to change out onoy because of all ac ducts and stuff in attic but as soon as I replaced it we could tell with inside temps in the house. I have two that we got from Home Depot they are like 74.99 each on a 2400 square foot house so far I am happy.

[Samhain]

Because hvac guys don't know anything about roof ventilation and they don't have to replace the damn things all the time. Yeah homeowners love them at first but then replace them with something else when they reroof their roof because they haven't worked in years. I hardly ever put power vents back on a house because the homeowners are tired of replacing them. Experience is why roofers hate them, inexperience is why everyone else likes them.

Allow me to retort... Roofers don't like powered vent fans because they are lazy. They don't like to deal with the electrical. Hell, most roofers use a fucking claw hammer to open holes in decking. The fact is people will see savings on their electrical bills. Lastly, with proper installation and correct t-stat settings, powered fans will last many years.

[propellerhead]

I belong to the whirly bird camp. Powered vents use electricity to run, which is what you are trying to save. Therefore, if a whirly bird and a powered one are moving the exact same amount of air, the whirly bird will provide a better net effect. Besides, cooling the attic is like cooling the outside of a Coleman cooler. Better insulation, window shades or tint, better door weatherstripping, etc. are better ways to lower your electric bill.

We have these types of threads every summer and the same arguments are made. Kinda funny now.

[mikec]

I'd say that's pretty arrogant and inaccurate, but maybe that's just me perceiving how you worded your response. Any HVAC guy worth his weight should know plenty about roof ventilation, because it affects heat loads.

I'm not saying a lot of them don't, but I'd think the good ones do. Sounds to me like another pissing contest between trades that are all too common, unfortunately. At any rate, I'm switching to power vents. My whirly birds hardly move, and if I can reduce attic temps 20+ degrees like I've seen happen with friends, I'm all over it. Whirly birds usually have to be replaced after a heavy hail storm anyways, which could mean yearly in a lot of cases in NTX.

You totally cut out the rest of his post, which was gold. wtf? We deal with this shit every day, we know this shit.

Sidenote: I need to get that brisket recipe from you B...

Allow me to retort... Roofers don't like powered vent fans because they are lazy. They don't like to deal with the electrical. Hell, most roofers use a fucking claw hammer to open holes in decking. The fact is people will see savings on their electrical bills. Lastly, with proper installation and correct t-stat settings, powered fans will last many years.

Sources? Your post is a bunch of bullshit that you pulled out of the dirty underwear basket. Just saying, as you obviously have zero knowledge of what is actually entailed. You are passionate though, so plus five points!

And as Brent said, and my past posts reflect, it is dependent upon the number of soffit vents allowing air into the attic to be sucked out.

In closing: Turbine vents rule!