Downdraft Performance? HELP

[Woodwerker]

We recenty purchased a Jenn Air Range with gas grill feature.
It has two gas burners and a gas grill similar to an outdoor BBQ element.
It has downdraft ventilation to pull smoke out of the house.
The downdraft is installed properly however whenever we use it the smoke detectors go off. It is working just not good enough. If anyone can lend an idea I would greatly appreciate it.
It is vented to outside the house, and is pulling smoke.
Thanks
Joe

[stewchi]

Eat raw food
Just kidding,
Is it the smoke detector in the kitchen that is going off? We have an electric stove with downdraft in the kitchen island. If steam is really coming out of the pot it will capture about ½, the ½ that is closest to the downdraft. Our smoke detector is a good distance away and I have not cooked anything that really smokes so I have not had that problem. The down draft systems will only capture a modest amount of stuff. If you are really Grilling and burning off a lot of fat you will need a large overhead hood to capture that sort of thing. I don’t think a down draft will do it.
You can try to beef it up with an inline duct fan, that might get you more CFM.

[gsmittle]

Eat raw food
Just kidding,
Is it the smoke detector in the kitchen that is going off? We have an electric stove with downdraft in the kitchen island. If steam is really coming out of the pot it will capture about ½, the ½ that is closest to the downdraft. Our smoke detector is a good distance away and I have not cooked anything that really smokes so I have not had that problem. The down draft systems will only capture a modest amount of stuff. If you are really Grilling and burning off a lot of fat you will need a large overhead hood to capture that sort of thing. I don’t think a down draft will do it.
You can try to beef it up with an inline duct fan, that might get you more CFM.

You could always go the Tim the Tool Man route and hook up a HF DC to the duct. Nothin' wrong with MORE POWER!!!!

g.

[Tom Slick]

how long is the duct to the outside? if it is a long run maybe it needs a booster fan inline.
just a guess

[Woodwerker]

Thanks guys, the duct is only 18 inches, I posted the question on an appliance repair forum and got some advice. I need to run the fan 10 minutes prior to cooking. I'll see what happens and post a follow up.
Thanks for the help.
Joe

[gonesailing]

Air Source

Been looking at articles on wood stoves and chimneys, and one problem that a lot of people are having is that the houses are too tight, and not enough air can get in, which limits the draft considerably and often leads to smoke inside. They say that the way to test is to open a window a very small amount and see if that helps. If it does, then you at least know what the problem is, even if you don't know how to solve it .

Mike L

[AlanJ]

Or just disable the smoke detector in your kitchen. In our old house (c 1985) it was going off all the time (LOML kept burning the toast ). we built a new house 2 years ago and the builder didn't put one in the kitchen. Code didn't require it and it saves us a lot of arm-waving. If a kitchen fire is serious enough to create smoke, it very soon gets out into the hallway/family/dining room where there are detectors.

[sneezer17301]

rather then venting to the outside I have my jennair vented to my basement shop. This serves two purposes. first I have a new tight house and the air inside will just circulate rather then try and draw new air in. Second, it helps heat my shop and smells great too.