Re: Is it really neceessary?
A hood serves three purposes: the obvious purpose of venting out odors and combustion gases (charred food and smoking oil also produce combustion gases); the slightly less obvious purpose of trapping airborne cooking grease (otherwise it goes all over the place); and the somewhat inobvious purpose of protecting the cabinets and other room surfaces from fire in the event of a flareup.
(Commercial kitchens are required to have hoods, and they are required to be kept clean. If grease is allowed to build up, it becomes a fire hazard. In my state, an unclean hood is considered a health violation and counts against the restaurant's health score.)
If it's not required by code, it's a really, really good idea to have a hood. If your kitchen is designed so that a standard hood won't fit right, you may have to have one custom made.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.