# controlling attic fan?



## 480sparky (Sep 20, 2007)

Most whole-house fan manufacturers make a two-speed controller.


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## BuzzKill (Oct 27, 2008)

...that or what comes with it? a temp setting/regulator?


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## Voltech (Nov 30, 2009)

If when you say "didnt work well" you mean, didnt pull much air. You need to make sure it has a way for the air flow both ways.

If not, disregard


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## GEORGE D (Apr 2, 2009)

Your right, instead I failed to mention it has a 2 speed pull-chain switch but barely differentiates between the two. I was wondering what controller would do a better job at that?


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## RIVETER (Sep 26, 2009)

Can you just install a two temperature setting switch in the attic and just forget about it?


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## crazyboy (Nov 8, 2008)

Are you talking about an attic fan or a whole house fan?


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## cdnelectrician (Mar 14, 2008)

480sparky said:


> Most whole-house fan manufacturers make a two-speed controller.


Boy that thing is helluva ugly! Wouldn't want to see that on my bathroom wall!


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## leland (Dec 28, 2007)

As posted- you need air in to get air out. Normally one would use a line volt T-stat- with an over ride feature.Or the device provided with the unit.


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## 480sparky (Sep 20, 2007)

cdnelectrician said:


> Boy that thing is helluva ugly! Wouldn't want to see that on my bathroom wall!



Who puts whole-house fans in bathrooms?


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## Voltech (Nov 30, 2009)

RIVETER said:


> Can you just install a two temperature setting switch in the attic and just forget about it?


Whole house fans dont work like that. You dont want them to pull out the bought air.


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## RIVETER (Sep 26, 2009)

Voltech said:


> Whole house fans dont work like that. You dont want them to pull out the bought air.


I thought he said attic fan...my bad.


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## Voltech (Nov 30, 2009)

RIVETER said:


> I thought he said attic fan...my bad.


My house is sealed tight, when I put my WHF in I had learn the hard way how they work. My system is perfected by doing it the wrong way the 1st time.:laughing:


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## RIVETER (Sep 26, 2009)

Voltech said:


> My house is sealed tight, when I put my WHF in I had learn the hard way how they work. My system is perfected by doing it the wrong way the 1st time.:laughing:


Mine is an attic fan that mounts through the roof; The temp. controller actuates the fan when the heat gets to 95 degrees.


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## TOOL_5150 (Aug 27, 2007)

when I installed my whole house fan, I just used a 3 way switch to control the 2 speeds, and a timer to control on/off. 

~Matt


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## idontknow (Jul 18, 2009)

What about a ceiling fan remote control? They're about $30-40 and give 3 speed control.


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## kwired (Dec 20, 2009)

idontknow said:


> What about a ceiling fan remote control? They're about $30-40 and give 3 speed control.


probably not designed to handle the current drawn by a whole house fan.

there are fan speed controls for higher amperages available - it must be a PSC type motor but most usually are. If two speed motor most cases I would use the two speed taps and a double throw switch (could use std 3 way but will need additional on - off switch.

There are automatic controls that vary the speed based on temperature, they will be pricey compared to a manual controller. I commonly see these controlling ventilation on livestock buildings and up to 1/2 hp or even more will not necessarily have the "look" desired in a home and most likely in a NEMA 13X enclosure.


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## Electric Al (Mar 13, 2010)

Yes, there are controls. e.g. Honeywell makes one. It is a thermostat that closes on temperature rise. Commonly used in cattle barns etc.


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## 480sparky (Sep 20, 2007)

OK, it seems there's some confusion as to what kind of fan is involved here.

Is it a whole-house fan, that is installed in the ceiling of the top floor......









......... is controlled by a pull-chain or a wall switch, and designed to cool the living space of the house?



OR, is it an attic fan that is not visible from the finished areas.........










...........that is controlled by a thermostat and is designed to remove heat from the attic only?


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## MDShunk (Jan 7, 2007)

I normally use a make-on-temperature-rise line voltage wall stat and a 3-way switch to pick which speed.


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## micromind (Aug 11, 2007)

It depends on what type of motor it is.

If it's single speed split-phase or capacitor-start, the speed cannot be controlled. If it's a two speed, any type of SPDT switch will work, but only high and low, not variable. 

If it's a PSC or shaded-pole, a variable speed control designed to work with motors (not lights) will work, provided it can handle the current of the motor. 

Rob


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## egads (Sep 1, 2009)

480sparky said:


> OK, it seems there's some confusion as to what kind of fan is involved here.
> 
> Is it a whole-house fan, that is installed in the ceiling of the top floor......
> 
> ...


Indeed! thread title: Attic Fan Description in first post: Whole house fan


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## Vintage Sounds (Oct 23, 2009)

How about just a timer? Most homeowners don't adjust whole house fans to the "optimal" speed setting for the particular situation. Having it shut off automatically might make it more useful for them.


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## GEORGE D (Apr 2, 2009)

micromind said:


> It depends on what type of motor it is.
> 
> If it's single speed split-phase or capacitor-start, the speed cannot be controlled. If it's a two speed, any type of SPDT switch will work, but only high and low, not variable.
> 
> ...


This is probably the answer Iwas looking for. BTW, I used a 3-way stack switch for the 2 speeds, the main problem is that the HO doesnt like the fact that the 2 speeds are barely different and would like to control speed completely. I also have a question for you guys, what is the difference of a motor controller and a dimmer?Does a motor cntrlr change the frequency?


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## GEORGE D (Apr 2, 2009)

Also, 480 listed the exact fan I'm dealing with (top picture). This is a direct drive versus the belt drive which I believe might be a better system(less noise, more power)


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## kwired (Dec 20, 2009)

GEORGE D said:


> This is probably the answer Iwas looking for. BTW, I used a 3-way stack switch for the 2 speeds, the main problem is that the HO doesnt like the fact that the 2 speeds are barely different and would like to control speed completely. I also have a question for you guys, what is the difference of a motor controller and a dimmer?Does a motor cntrlr change the frequency?


 


> 430.2 Definitions.
> 
> Controller. For the purpose of this article, a controller is any switch or device that is normally used to start and stop a motor by making and breaking the motor circuit current.


Variable frequency drives change frequency. Most variable frequency drives meet the definition of motor controller.

The speed controls used on a motor of this type do not change frequency. They do reduce power to the motor by cutting voltage waveform which results in less effective voltage supplied to motor. 

If the speed control has an off position it is a motor controller by 430.2 defintions.


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## Toronto Sparky (Apr 12, 2009)

GEORGE D said:


> I also have a question for you guys, what is the difference of a motor controller and a dimmer?Does a motor cntrlr change the frequency?


Motor speed control turns on at full power and gets slower as you turn it up.
Most speed controls also have a trimmer pot to set the slow speed high enough that your fan will not stall and burn out.. 


Dimmer starts low and gets higher as you turn it up..


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## Voltech (Nov 30, 2009)

480sparky said:


> OK, it seems there's some confusion as to what kind of fan is involved here.
> 
> Is it a whole-house fan, that is installed in the ceiling of the top floor......
> 
> ...


A good system or mine uses both. If your WHF pulls hot air into the attic, you need to be sure it has a place to go. An Attic fan really makes a difference. 

Mine is an old 120v heater box gutted, that blows air into the attic with a homemade damper. The attic fan pulls that air out. The damper is used so in the summer time I run just the attic fan and it not draw out the bought air.


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## Ocularpatdown (Apr 27, 2010)

Voltech said:


> A good system or mine uses both. If your WHF pulls hot air into the attic, you need to be sure it has a place to go. An Attic fan really makes a difference.
> 
> Mine is an old 120v heater box gutted, that blows air into the attic with a homemade damper. The attic fan pulls that air out. The damper is used so in the summer time I run just the attic fan and it not draw out the bought air.


I've read many times that a properly ventilated (and insulated) attic is more efficient than using an attic fan. An attic fan might move the hot air out quicker than a passive system, but it itself uses electricity. If the attic is properly ventilated (i.e.. ridge vent and soffit vents, etc.) and insulated, it will cool itself enough that it won't effect the temperature of the house, or at least not enough to make the AC unit run more and use more electricity than an attic fan uses.

That's what all the research I've done has concluded.

Also, if you have a well ventilated attic, a whole house fan should be able to push that attic air out itself, it won't need the help of an attic fan.


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## kwired (Dec 20, 2009)

Ocularpatdown said:


> I've read many times that a properly ventilated (and insulated) attic is more efficient than using an attic fan. An attic fan might move the hot air out quicker than a passive system, but it itself uses electricity. If the attic is properly ventilated (i.e.. ridge vent and soffit vents, etc.) and insulated, it will cool itself enough that it won't effect the temperature of the house, or at least not enough to make the AC unit run more and use more electricity than an attic fan uses.
> 
> That's what all the research I've done has concluded.
> 
> Also, if you have a well ventilated attic, a whole house fan should be able to push that attic air out itself, it won't need the help of an attic fan.


The reason for attic ventilation whether powered or convection is to reduce moisture problems not because of heat.


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## Ocularpatdown (Apr 27, 2010)

kwired said:


> The reason for attic ventilation whether powered or convection is to reduce moisture problems not because of heat.


To an extent, yes, moisture can be a problem, especially in the Winter.

However, this statement: "not because of heat." is completely false, at least in most parts of the country that get heat during the Summer. 

Ventilation in the attic plays a very important part of keeping the house cool (saving on energy costs) as well as extending the life of the roof. Many roofing contractors won't warranty your roof if you don't have proper ventilation, the excess heat will destroy it rather quickly.


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## Toronto Sparky (Apr 12, 2009)

Anyone that has had insulation blown in will probably find all the soffit vents blocked.
Or if the house is old enough (like mine) there is so many layers of paint on them they are mostly plugged. 
Last time the roof was replaced (two years ago) the contractor added three roof vents (non-powered) , But I still have to clean out the soffit vents.

Kind of hard for us old guys to squeeze into those tight areas of the attic to install the proper soffit vent shields that are used these days to keep insulation from blocking them..


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## randomkiller (Sep 28, 2007)

I like to use one of two ways for a WHF, either two thermostatic switches (one for each speed) or a combination humidistat/thermostat for the low speed, and also a 
wall switch near the attic opening.


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## GEORGE D (Apr 2, 2009)

To me it seems that a WHA fan is more useful cooling the inside of a home rather than the attic. My parents had one growing up and you could cool the house down enough in the beginnings of summer that you could hold off on the ac for some time, I am speaking of nights and evenings of course, but we would set it on low and have no trouble sleeping.Surely they are designed more for cooling down the attic,right?


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## Voltech (Nov 30, 2009)

GEORGE D said:


> To me it seems that a WHA fan is more useful cooling the inside of a home rather than the attic. My parents had one growing up and you could cool the house down enough in the beginnings of summer that you could hold off on the ac for some time, I am speaking of nights and evenings of course, but we would set it on low and have no trouble sleeping.Surely they are designed more for cooling down the attic,right?


Thats what I use mine for. In the summer-spring days the ac is set at about 80, and when I get home it can be that hot still inside, but 65 outside. I turn on my system while taking a shower get out and its a cool 65 inside.


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## kwired (Dec 20, 2009)

GEORGE D said:


> To me it seems that a WHA fan is more useful cooling the inside of a home rather than the attic. My parents had one growing up and you could cool the house down enough in the beginnings of summer that you could hold off on the ac for some time, I am speaking of nights and evenings of course, but we would set it on low and have no trouble sleeping.Surely they are designed more for cooling down the attic,right?


They are designed to draw cooler outside air in usually through open windows and exhaust warmer air that naturally hangs around near the ceiling. The attic will happen to get cooled also in this process.


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## StopBanningMeBro (May 5, 2010)

Anyone know of a remote and receiver that could handle a 4,500CFM whole house fan? Probably under 4 amps.


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## user4818 (Jan 15, 2009)

StopBanningMeBro said:


> Anyone know of a remote and receiver that could handle a 4,500CFM whole house fan? Probably under 4 amps.


X10 system or equivalent.


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## StopBanningMeBro (May 5, 2010)

Peter D said:


> X10 system or equivalent.


Have you used one with success? I fear using dinky X10 stuff with higher amperage devices unless they have been tested out.


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## user4818 (Jan 15, 2009)

StopBanningMeBro said:


> Have you used one with success? I fear using dinky X10 stuff with higher amperage devices unless they have been tested out.


Personally, no, but I worked for a contractor who installed the stuff all the time with great success. 

They make a 20 amp rated module for heavy duty loads.


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## StopBanningMeBro (May 5, 2010)

Peter D said:


> Personally, no, but I worked for a contractor who installed the stuff all the time with great success.
> 
> They make a 20 amp rated module for heavy duty loads.


Great, I'll look into them. Thanks Peter!


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## ItsMe (May 5, 2010)

I looked but I'm not seeing it, Peter. Did you have any specific models in mind?


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## user4818 (Jan 15, 2009)

ItsMe said:


> I looked but I'm not seeing it, Peter. Did you have any specific models in mind?



http://www.smarthomeusa.com/ShopByManufacturer/X-10-Pro/Item/XPFM/


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## ItsMe (May 5, 2010)

Peter D said:


> http://www.smarthomeusa.com/ShopByManufacturer/X-10-Pro/Item/XPFM/


So in addition to that, i would need one of those controllers that plugs in and converts the radio signal into the power line, and then a remote control?

I never looked into this X10 thing, much. I remember when I was a kid Radio Shack sold this type of stuff.


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## user4818 (Jan 15, 2009)

ItsMe said:


> So in addition to that, i would need one of those controllers that plugs in and converts the radio signal into the power line, and then a remote control?
> 
> I never looked into this X10 thing, much. I remember when I was a kid Radio Shack sold this type of stuff.



Yes, you need the transceiver and the on/off control itself. The on/off control can take many forms, from a wall switch to a keychain pendant to a control button that sticks onto the wall. 

Any particular reason this needs to be done by remote control?


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## ForumGlitch (May 5, 2010)

There must be a glitch in the forum because I keep getting kicked out and my IP banned. If anyone is out there, let me know.


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## user4818 (Jan 15, 2009)

ForumGlitch said:


> There must be a glitch in the forum because I keep getting kicked out and my IP banned. If anyone is out there, let me know.


I'm here. :thumbsup:


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## kwired (Dec 20, 2009)

StopBanningMeBro said:


> Have you used one with success? I fear using dinky X10 stuff with higher amperage devices unless they have been tested out.


Use it to control a contactor and you can control pretty much any load.


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## markore (Dec 7, 2011)

*2 windings - 3 speeds*

Sorry to resurrect an old post (again) :whistling2: but I just wanted to chime in that SOME fan motors that have two windings can actually be set for three speeds because when you energize both sets the fan will actually run faster than just 1 or 2 alone. 

Just something to be prepared for when you unbox a new brand; you may want to test the operation (vibration, noise, level, performance) in all three states and plan your control relay network accordingly.


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