vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UberDork
8/21/23 3:44 p.m.

The fan in my attic stopped working. It is controlled by both a humidistat and a thermostat. There is power from both sensors to the fan. This little black box appears to have had a melt down. Know what it is? Is it replaceable? Do I need a new fan assembly?

Box in red circle. Apparently melted stuff in orange.

maschinenbau
maschinenbau UberDork
8/21/23 3:58 p.m.

If you also have ridge vents and soffits, the current thinking seems to be that attic fans just aren't needed anymore, and could actually work against the natural flow of ridge vents.

1988RedT2
1988RedT2 MegaDork
8/21/23 4:17 p.m.

In my experience, a thing hanging off a fan motor is typically a capacitor used to help start the fan.  You could remove the box, check for markings, see if what's inside looks like a capacitor.

Turn off the power before messing with it.

Vacuum the gunk out of the vents on the motor.

1988RedT2
1988RedT2 MegaDork
8/21/23 4:27 p.m.

Depending upon the motor size, you should find markings like "10 mfd, 250 v." or something similar. 

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UberDork
8/21/23 11:32 p.m.

Older house without soffit or ridge vents.

I will remove it and look for markings,

Lowes has fans for $100 so that is an option. This fan has got to be a decade old or so.

porschenut
porschenut HalfDork
8/22/23 8:06 a.m.

I have found that the cheap fans have a 5-10 year life.  So if you fix that something else may crap out in a week.

pheller
pheller UltimaDork
8/23/23 2:41 p.m.

What's a good fan?

My house, built in 97', doesn't have much roof venting at all. Just the gable vents. I've been running a box fan, hung in front of a vent, pointed out, up there for the last couple of weeks and it significantly cools the roof, which in turns helps cool the house. 

I've pondered putting some rigid foam on the underside of the roof deck just to bring attic temps down a bit during the summer, as I like storing stuff up there and I'm tired of it getting 120º. 

Mndsm
Mndsm MegaDork
8/23/23 2:45 p.m.

I don't have ANYTHING useful to contribute, but absolutely every time I read this post I think "who the berkeley is attic fan and why do I care? " 

1988RedT2
1988RedT2 MegaDork
8/23/23 2:50 p.m.

Any fan would be better than no fan.  Any home center should have a selection of suitable attic fans, louvered exhaust fans, etc.  Most are cheaply made.  Specialty fan manufacturers such as American Coolair Corp. of Jacksonville, FL make a high quality line of fans, but most here would find them quite expensive.

 

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UberDork
8/23/23 9:54 p.m.

In reply to Mndsm :

laugh

OHSCrifle
OHSCrifle UberDork
8/23/23 10:23 p.m.
maschinenbau said:

If you also have ridge vents and soffits, the current thinking seems to be that attic fans just aren't needed anymore, and could actually work against the natural flow of ridge vents.

I believe @vwcorvette said he has no soffit or ridge vents but I enjoy reading about this stuff, and offer the following "because rabbit hole"...

https://www.energyvanguard.com/blog/is-it-ever-helpful-to-use-a-powered-attic-ventilator/

And to me, this is the #1 highlight:

“They’re a solution to the wrong problem. The heat gets into the attic by radiating down from the hot roof deck. Using a fan to address radiant heating is like thinking you can’t get a sunburn on a breezy day”

Aaron_King
Aaron_King UltimaDork
8/24/23 9:19 a.m.

The thing I remember about attic fans, and maybe this is something else entirely, was at night in the summer my parents cracking open a few windows on the ground floor, turning on the fan and getting a nice breeze through the house.

pres589 (djronnebaum)
pres589 (djronnebaum) UltimaDork
8/24/23 9:44 a.m.

Yeah, I'm wanting to add an attic fan to my garage so I can have it draw the existing heated air out of the building fairly rapidly in the late afternoon / early evening when the air outside the building is cooler than inside the building.  Even if my garage had good ventilation like vented soffits I would still want the attic fan just to speed up the process.

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