Quote:
Originally Posted by imagesinglass
Mike said: "Pretty much *any* kitchen hood will work with modifications - the mods needed are usually completely gutting the hood and making a good round hole in the top that ducting can attach to.
What's needed is the measurements of the hood coverage area so that the fan CFM's can be calculated. Then I need to know the length of the run and the number of 90 degree bends needed to get to the outside."
Hi Mike,
I have a kitchen hood fan I've been using for 1 year as my ventilation. Now I'm getting concerned about how well it is actually working. It's 350 cfm on high, which I always use. The hood measures 30 x 19-1/2" and has 2 90 degree bends and is 5 feet long. The ducting is 6" round smooth ducting. I've closed the space under the fan on three sides with plexiglass (so I don't feel claustrophobic). My torch is a minor and does not sit totally under the hood...most of the flame is directly under the hood. I also wear a half respirator when I'm working just as a secondary precaution.
Is my ventilation adequate?
I also recently bought a 440 cfm canfan but it's very big and heavy really loud. My workshop is only 10 x 8 and I can't take the noise...
Thanks for any assistance you can provide.
Suzanne
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All figures are recommendations only. The ducting design and distance from the hood are as important as the fan size. The ONLY way to confirm your vent system works is with a smoke test. You can buy smoke test sticks at most hardware stores or use a lit candle, burning incense stick, or lit cigarette. Move the smoke originater to various spots where you will be working and watch see if all the smoke is drawn out the exhaust. If it isn't, you need to either increase the exhaust capacity or reconfigure the work area to improve exhausting. Changing your 90 degree bends to double 45's would make a huge difference to air flow efficiency.
I've seen many shops with less then 350 cfm vans that vent perfectly.