Hey “all,” long time no post. Have been finaled for over a year now, the Australian wife is here now along with the two step-kids, everyone doing fine save for the usual life expectancies of family life; oh, and then there was the rare (one or two in a million get it) blood disease, TTP, that I contracted just after Thanksgiving ’06, but that’s a whole other story. Anyway, I’m doing a few little projects here and there and one of them is installing the Viking ventillation system above the gas stove top.
I’ve got an island DEV 900 (900 cfm) external blower w/ DIH 42″ hood Viking system that is a bit oversized for the stove top which I did on purpose cause I’m cheating the height spec a little; Viking recommends a max of 36″ space between the counter top and bottom of hood; I’m stretching that to 42″ as my own height is 5’16” and I didn’t want to have to “duck” under the hood to see across the living areas of the house to yell at the kids or otherwise engage someone.
After plumbing up where the duct cover will rest up against the ceiling, above the hood (obviously), I come to discover that one of the ceiling joist will be slightly in the way as I run 10″ duct to the blower. My question is, would it be “sound” if I come off the hood with 10″ duct, reduce to 8″ duct, bypass the ceiling joist with a six inch run or whatever, and then go back to 10″ ducting again???
What I’ve also considered is “cheating” the hood a little bit towards the back of the stove top about an inch, and then can probably, through making the duct slightly oblong, make the pass by the ceiling joist.
Thanks ahead of time for the help…
Replies
Without doing the calculations (which I don't know how to do), what is generally done is to transition to oval without decreasing the cross sectional area.
i have little science to back this up... but i don't think you want to build 10 to 8 to 10
that would be a venturi... (sp)
I do think you'd be better make'n it all 8" and have a little fall back to the hood... the increased speed of the air would keep the deposits down on the inside of the duct... anything else that you do I think would be somewhere for grease to gather...
but... that just my 2cents..
p