Attic (roof) fan; yes or no?


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Old 07-17-20, 06:01 AM
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Attic (roof) fan; yes or no?

When we bought our coloinal-style home (in southern CT) 8 years ago, the home inspector noted that the attic fan wasn't working. My question is; is it a no-brainer to fix/replace it (yes, it's taken me 8 years to finally get around to it), or are there certain factors I should consider (I've been reading a lot of threads here so I'm not certain what to do)? Below is a pic similar to what I have (not my actual roof/fan).

We have central a/c (unit is in the attic) with 1 zone that covers the whole house (which I hate by the way and would love 2 zones, but I digress). Upstairs has both more vents and I think shorter runs in the attic (the ducts from the unit to the vents are more direct to the upstairs vents) so the upstairs actually gets cooler than downstairs.

Insulation was also weak when we bought the house so we had insulation blown in and air sealing done.

I also have something like this in the attic above the pull down stairs: BATTIC DOOR® R-50 ATTIC STAIRS INSULATOR COVER NOW AVAILABLE IN 3 SIZES: 22x54, 25x54, and 30x54

There are vents at both sides of the attic.

House is approx 44' x 25', with a relatively low pitched roof (I can't stand up in the attic and I'm 5'6").

Given the above, should I absolutely fix/replace the fan? I assume the existing one was hardwired to power and had a temperature sensor telling it when to go on/off. Should I keep that setup or get solar (it would get sun almost all day, starting around 11 AM or so).

Thank you.

<img src="https://cimg4.ibsrv.net/gimg/www.doityourselft.com-vbulletin/480x360/hqdefault_2efdc0067f0c3accfabee00db161622e97028195.jpg" width="480" height="360"/>
 
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Old 07-17-20, 07:49 AM
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I'd want to get that fan running again.
It's far more common to see a fan like that wired to a switch someplace, not hard wired.
If there is no switch, I'd be adding one to make it easier to service in the future.
To trouble shoot, I'd be checking to see if there's power to the fan, if there is then figure out what breaker shuts it off so you can work on it.
Most often it's a bad commonly avalible thermostat.
 
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Old 07-17-20, 07:52 AM
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Ok thank you. This is a little beyond me so I'll likely have my electrician come and take a look.
 
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Old 07-17-20, 08:30 AM
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Try calling your local utility and ask if they have someone who does energy audits. If you can find such a person just to ask over the phone you may get the same answer I got years back- those fans pull air from the soffit vents between the rafters where the fan is installed and do little to remove any other air from the attic. If you get that answer I suspect it would be a waste of electricity to power that fan.

You could consider adding a continuous ridge vent now or next time you reroof.
 
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Old 07-17-20, 10:50 AM
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Don't waste your money on a solar vent fan. A single unit will not cool an attic.

Like Joe mentioned.... I'd definitely get that fan fixed. Yes.... a roof ridge vent is ideal but is not something easily added unless re-roofing.

I have 8 soffit vents and then I added two roof jacks to the roof at the farthest point to the fan. The point being you need to have enough incoming fresh air openings or the fan will draw air from inside the house and that's not good.
 
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Old 07-17-20, 10:52 AM
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Thanks guys. Hopefully the vents on either side will allow for enough fresh air flow.

Once the fan is fixed, is there something I should look for to make sure all is working well and it's not sucking air from in the house?
 
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Old 07-17-20, 11:38 AM
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I couldn't imagine not having an attic fan. They do so much to remove the hot attic air. The post above from joe was what my first thoughts were... I'd bet you have (or not) a switch for that fan.... and if you do have soffit venting, that may not help you to vent the attic well. As for sucking air from the house, you should have a air-tight access into your attic... mine has a door seal and hook to keep it tight.
 
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Old 07-17-20, 01:04 PM
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Thanks and it looks like I do have soffit venting (or at least baffles, sorry, I don't exactly know what all this means). This is part of what the insulation company did when we moved in:

"Attic Prep & Insulation: Prep- install baffles at soffits to maintain attic ventilation...."
 
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Old 07-17-20, 01:10 PM
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Soffit vents bring air into the attic, the baffles give that air a path up to the attic space. Otherwise the insulation will stop/block that air flow.
 
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Old 07-17-20, 01:13 PM
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So given the above, is an attic fan not a good idea as it looks like it will draw air from the house to the attic?
 
 

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