# Recommendations for inline duct fan??



## mtek (Dec 10, 2013)

Hi All,
In order to move air heated by our Lopi into the Living Room I intend to install a six inch flexible duct under the floor of the room to suck cold air out and move it to the other end of the house.  This causes the Living room to warm up nicely.  I currently have the ducting and a spare bathroom fart-fan rigged up temporarily on top of the floor to test it.   It works really well and so now I need to get a proper inline 6 inch duct fan and install everything in the basement.  This will keep she-who-must-be-obeyed happier as stepping back and forth over the duct is not her idea of fun.

Does anyone have an experience of any specific fans or makes/models to recommend or stay way from??

Thanks Everyone and Merry Christmas to all!!


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## MDFisherman (Dec 10, 2013)

Greenheck, Penn Zephyr, and cook are all premium fans that cost a lot of money.

If this was me and for my house, I would go with a cheapo, like whatever is available at home depot or lowes.  You could also get a Dayton from graingers.  I have used their fans and motors in the past with good success.

Make the supply/return grille's bigger than they need to be to keep the face velocity down at the grilles.  If you do go with a cheapo I would go for an oversized fan (CFM's) as I doubt the fan will put out what it says on the box.  The volume will also be reduced at the blades of the fat get dirty over time. 

Also, 6" round duct is fairly small, 150CFM is about the most you can push through before it becomes annoying (whistling and nuisance velocities) .  Might want to look into an 8" duct or even larger.


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## mtek (Dec 10, 2013)

Hi MDFisherman,
I'd love to go with 8" but some of the spaces I have to route the duct in the basement are pretty tight so it has to be 6".  The main reason I asked at all is that I looked at reviews on Home Depot's site for inline fans and a surprising number of people complained about excessive noise and vibration.   I was hoping someone here would be able to name a relatively cheap fan that wouldn't sound like a C-130 Transport winding up for takeoff!


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## begreen (Dec 10, 2013)

Allow for this duct to be well insulated or the heat loss may negate the gains. If necessary go with a 5 or 4" fan. It doesn't take high cfm to get a convective flow going.


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## mtek (Dec 10, 2013)

begreen said:


> Allow for this duct to be well insulated or the heat loss may negate the gains. If necessary go with a 5 or 4" fan. It doesn't take high cfm to get a convective flow going.



And the proof of your comment is that the little bathroom exhaust fan I've used to test the concept is rated at 50 CFM and it's worked out very well.


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## MDFisherman (Dec 11, 2013)

mtek said:


> Hi MDFisherman,
> I'd love to go with 8" but some of the spaces I have to route the duct in the basement are pretty tight so it has to be 6".  The main reason I asked at all is that I looked at reviews on Home Depot's site for inline fans and a surprising number of people complained about excessive noise and vibration.   I was hoping someone here would be able to name a relatively cheap fan that wouldn't sound like a C-130 Transport winding up for takeoff!


 
Then look for a fan with a low sones rating... you can insulate the fan motor and will help with the noise also

Just to be sure you're sucking cold air from the back of the house and blowing it into the stove with the room correct?  

 In which case I do not see how insulated duct would really be necessary (but the black flex duct already has some insulation built in)


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## mtek (Dec 11, 2013)

Hi again MDFisherman,
Yes, I am sucking the air from the area I want heated and 'dumping' it into an area that is heated directly by the stove.  I am aware of the importance of low sones ratings but so far have not seen any for this kind of fan.  The bathroom extractor fans and some other advertise them widely but not these so much.  When you say 'insulate the fan motor' how would you propose I do that?


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## begreen (Dec 11, 2013)

A 100 cfm, 4" axial (muffin) fan should be quiet and adequate. Make your own fan box for it with 4" round in/out connectors.
Or use a very quiet, remote bathroom fan like this:
120 cfm:  http://shop.panasonic.com/shop/model/FV-10NLF1
240 cfm: http://shop.panasonic.com/shop/model/FV-20NLF1
These blowers are already sound insulated and ready to hang.


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## MDFisherman (Dec 11, 2013)

mtek said:


> Hi again MDFisherman,
> Yes, I am sucking the air from the area I want heated and 'dumping' it into an area that is heated directly by the stove.  I am aware of the importance of low sones ratings but so far have not seen any for this kind of fan.  The bathroom extractor fans and some other advertise them widely but not these so much.  When you say 'insulate the fan motor' how would you propose I do that?


 
You can wrap the entire fan assembly in some duct wrap insulation and secure it with duct tape.  You can cut a hole in it for access to the electrical connections etc.


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## mtek (Dec 11, 2013)

Thanks guys.  I'm going to go with the Panasonic FV-20NLF1.  We installed another panasonic bathroom fan a while ago that is so quiet I installed a timer to prevent it being left on too long.  I forgot all about it so I am very appreciative of the suggestion by begreen.  I'll let you guys know how it turns out when I have finished the project.

Thanks for the advice to all of you.


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## mtek (Dec 25, 2013)

Hi Everyone,
Merry Christmas to all of you and I hope you are all toasty warm with a roaring wood fire    Just wanted to report back that I completed the project described above and it works really well.  We've had it working over the last few days and I've noticed that when it's running our regular natural gas central heating never comes on.  The fan will pay for itself very quickly!!

As an aside I acquired a Condar spring-steel thermometer a few years ago when I got my steel catalytic convertor.  This Christmas I got one of those Klein dual laser IR thermometers.  Using the IR device it appears that the old thermometer is fairly accurate up to about 500F.  After that it tends to under-read by around 150F if the stove gets up to around 700 - 725F.  

So, again, thanks to all who answered my original question.

I hope you all have a really great 2014

Regards,
Jim


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