Exhaust fan sizing...

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ultramegabob

ultramegabob

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Indiana
I have a customer that has converted a house into a dog grooming business, I need to install a wall mounted fan to exhaust steam/water vapor out of a room that is approx 700 cubic feet, what size cfm fan should I use? I need it to move alot of air, but I dont want to suck the peoples hair sideways when they are working:D
 
How many air changes per hour do you want? It looks like the fan may work fine for you and it is speed controlled.
 
If you base your fan at 285 cf per min that will give you aprox 24 air changes per hour which seems like it should be adequate.
 
That would probably be a good idea. If you do not have enough intake air your fan will pull from anyplace it can. I've seen on a much larger scale when large industrial fans were not sized properly with intake air they sucked thru unit heater exhaust tubes and created a carbon monoxide problem. I would speed control the fan and if money were not an object possibly intall a motorized damper. (not necessary)
 
Vent Fan

Vent Fan

That fan is kind of big. Standard venting for a bath is 1CFM per sq-ft (2CFM if a whirlpool or jetted tub is installed) with a 50 CFM min. You spec'ed 700 cu-ft and with a 7 foot ceiling I'm guessing a 10x10 room. If this was a bath you would use a 100CFM fan or 200CFM with the whirlpool and that would give you PLENTY of venting. You will be exhausting a lot of heated or cooled air, plus the noise factor 6.6 is high for a small room.

There are a lot of quiet bath fans out available. Do you need a wall mount?

See:
http://www.grainger.com/Grainger/items/4TR42
http://www.grainger.com/Grainger/items/4TR44
 
ultramegabob said:
I have a customer that has converted a house into a dog grooming business, I need to install a wall mounted fan to exhaust steam/water vapor out of a room that is approx 700 cubic feet, what size cfm fan should I use? I need it to move alot of air, but I dont want to suck the peoples hair sideways when they are working:D
Click to expand...

if there's a way you can use a remote fan in the attic, to keep the noise down,
i am very fond of these... they are a 6" inline fan. they are very quiet.
you'll get an air change every two minutes. i have them in each of my bathrooms.

the last one i bought was about $175. nothing else even comes close. in one of my
bathrooms, about 700 cubic feet, you can run full hot water from the shower, and
no steam leaves the shower stall. it is a bit breezy, but not objectionable.... :)

Panasonic # FV-30NLF1

panasonicfan.jpg
 
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Jimbonh said:
That fan is kind of big. Standard venting for a bath is 1CFM per sq-ft (2CFM if a whirlpool or jetted tub is installed) with a 50 CFM min. You spec'ed 700 cu-ft and with a 7 foot ceiling I'm guessing a 10x10 room. If this was a bath you would use a 100CFM fan or 200CFM with the whirlpool and that would give you PLENTY of venting. You will be exhausting a lot of heated or cooled air, plus the noise factor 6.6 is high for a small room.

There are a lot of quiet bath fans out available. Do you need a wall mount?
Click to expand...

I double checked today and the actual dimensions are 10x11x7 for a total of 770 cubic feet, this is not a "bathroom" it is a commercial "dog bathing room" and from what I gather talking to the customer, it is very humid in there, the present room they have been using has a screen door that is left open the entire time they are open even during the winter, the room next room over is a drying room with cages with hot air blowers that run constantly drying the dogs off, so I guess drawing heat out of the building is not a big issue. the customer origianally purchased an attic exhaust fan to vent the room, but I talked them out of making a home made power vent when complete units were already designed for the task that had dampers and protective screens over the blades. I would rather go a little overkill with the unit and be able to use a variable speed controller on it to slow it down. another fan I am looking at is this one that is a little smaller. http://www.grainger.com/Grainger/items/1HKL9

and to answer your question, yes it has to be wall mount...
 
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