Sooo confused about ventillation

[ajwhite]

Hi everyone~

I've decided to get away from the dual fan in the window and get a vent hood of some type.

Can someone tell me the min. CFM I need? I thought it was 640 but then I've seen others use range hoods that are less - and cost less! I was going to go with the Glasscraft hood but was looking into a less expensive option even though it is really nice and already put together.

If I got a range hood I need to put baffles on the sides right? Does anyone know how far down the baffles should go? I don't really have the option of building a "Barley Box" in my little mudroom so I thought the hood with baffles would be a better option.

Ugh....I'm so confused!!!!

Thanks for your help!

Audra

[Dale M.]

I am personally beginning to think the "work station" concept (negative pressure booth) of hood/vent is best... See second picture in this thread for example of "work station"....

http://www.lampworketc.com/forums/showpost.php?p=23148&postcount=1

Also have come to believe anything less than a 500CFM fan/blower is a just a joke and one is fooling ones self.... Also one should use 8 inch or larger vent duct with a minimum of turns. Best way is to have exhaust go up and out wall with one 90° turn if possible. Range hoods just don't get it as far as I am concerned. They have no side "curtains" (partitions)to direct air flow, and people tend to mount them to high. They should be no more then the top of your head in height (just high enough that you don't hit them while at work).

Also just as important as fan/hood combination is make-up air.... If you don't have make-up air, the booth/fan is for nothing as you will have no air flow... So make-up air is the other 50% of ventilation.

Dale

[ajwhite]

Hi Dale!
I have a window directly behind me - that's what I've been using for make-up air. The vent hoods I've seen on ebay are 640 cfm - I would vent out the top into the attic and then through the soffit - so 1 90 degree turn I think.

If it works out like the pictures in my head - the hood would be mounted and then additional metal flashing added around the sides of the hood to bring it down more. I like the concept of the work station but it just isn't practical in my workspace - wish it was. It is a small room.

I think I'll continue researching but the more I research, the more confused I get!

Thanks!
Audra