Combined Kitchen Ventilation ( Continuous+ Intermittent )

[EnOm]

Hi
I have a rather large residential kitchen and I already have an Exhaust Kitchen Hood (550 CFM) in there. The kitchen hood will operate intermittently. Would there be an added benefit to adding a Ceiling Exhaust Grill linked to the residence's continuous exhaust system?
If there is an added benefit from this an issue, I'm also thinking about is that any vapors grease..etc remaining in the air would leave a smear on the ceiling around the exhaust grill. Is this true or am I being too cautious?

Best Regards

 

[chicopee]

For kitchen restaurants of any large magnitude, your best bet would be to have a push pull system which is expensive. In the long run, however, you could save on A/C and heating loads.
Tying up to an existing exhaust system, you will reduce the exhaust flows of the existing exhaust vents already in line and become subject to the irate ranting of the people being affected.

 

[EnOm]

chicopee,
Thank you for the response. Don't think a Push-Pull system is necessary on this project.
As for your second comment, the entire project is still undergoing design, nothing has been built yet so the issue you mentioned should not be a problem. So do you recommend this approach? Or is the intermittent exhaust from the Kitchen Hood sufficient for a high level of air quality?

 

[willard3]

The kitchen hood/fan should be adequate if properly sized and you can guarantee that it will be on when there is cooking. You want to keep the kitchen negative to the other spaces.

 

[EnergyProfessional]

he said residential kitchen, not commercial.

but in residential kitchen you need a MAU when you exhaust more than 400 cfm. Not sure what sort of residence that is that you need more than 400 cfm. Unless it is a mansion with servants that cook for elaborate dinner parties....

probably best not to return any kitchen air to the regular building exhaust assuming when you cook you turn on that hood. If you really make that much grease, you don't want to dirty-up your regular exhaust system.

 

[chicopee]

I do not recommend tying into an existing exhaust system because it will affect other exhaust vents and you can be assured that complaints about cooking odors will abound.

 

[SAK9]

A General exhaust grill be useful while warming food in the micro wave which could generate some odour.It can also help to get rid of the burnt smell when that raisin bread slice gets over toasted

 

[EnOm]

Willard3,
Thank you for the response. I am sizing my hood according to 100 CFM per linear foot of range. As for guaranteeing that it will be on I guess that is the owner's responsibility?

HerrKaLeun,
Thank you for theh response. Well you are spot on. It is a mansion with servants that cook for elaborate dinner parties. I do have makeup air, but not through a dedicated MAU, but through the central FAHU.

Chicopee.
Ah now I get you. Can't the odors be avoided if I place Non Return Dampers in the ductowork?

SAK9:
Thank you for the response. That is kind of what I was thinking. But I see that most of the replies don't recommend it. I guess I will do without the Exhaust Exhaust grill especially that the kitchen is in an isolated area.

 

[chicopee]

No, odors always find a way to get around man made obstacles. I suppose you could investigate an air ionization ozone maker since such device will control certain type of odors.

 

[trashcanman]

Here is what the IMC says,

"506.3.5 Separation of grease duct system. A separate
grease duct system shall be provided for each Type I hood.
A separate grease duct system is not required where all of
the following conditions are met:
1. All interconnected hoods are located within the same
story.
2. All interconnected hoods are located within the same
room or in adjoining rooms.
3. Interconnecting ducts do not penetrate assemblies
required to be fire-resistance rated.
4. The grease duct system does not serve solid-fuel-fired
appliances."

I would not interconnect them unless conditions 1 -4 are met.

Also, if the regular exhaust duct has dampers, do not interconnect them. Dampers are not allowed in grease ducts.

 

[sprinkler1000]

Following what Herrkaleun said, it will do more harm than good to mix any kitchen air with the rest of the house ventilation.

 

[MintJulep]

Relevant article in this month's ASHRAE Journal.

 

[EnOm]

chicopee,
Thank you for the response.

trashcanman,
Thank you for the response. That was very helpful insight.

sprinkler1000,
Thanks to you as well for the seconding.

MintJulep,
Thank you for the response. I guess I will look it up.

Best Regards