Residential range hood-high rise building

[flamearrow]

Hi Guys,

We have 28 kitchens in a 7 storey apartment connected to 2 no of roof top exhaust fan. designed CFM for a kitchen is 80. when I checked with suppliers of range hood, I could not find hood having pressure loss data.most of the hoods are more than 200 CFM, which I think too high. because supply air flow(conditioned) to a kitchen is 150 CFM. if the hood does not match the designed value can I use fabricated hood without filter which may decrease fan ESP problem. I also tried some hood with dedicated fan but its CFM was min.300
could anyone suggest suitable range hood for mutlistorey residential application?

 

[joecampbell]

you want as much exhaust as you can get. 200 is too little.

broan allure qs2, basically the same fan that was used in 1980.

http://media.datatail.com/docs/specs/45335_en.pdf

ranges produces a lot of heat and fumes, you don't want either in your building. code minimum rate i think is like 40cfm so it can be done but no one will like it. unless they eat only take out.

 

[SAK9]

When a duct serves multiple fire compartments,are you not required to have fire dampers installed on the exhaust duct at each kitchen connection? And fire dampers are not common on kitchen exhaust.

 

[flamearrow]

Thanks Joe Campbell, your attachment was useful.

 

[dbill74]

Why do you think 200 CFM in the hoods is too high?

I agree with Joecambell, 200 is on the low side.

The design airflow into the kitchen being less than the hood is actually a good thing. It will keep odors and more importantly smoke in the kitchen. If supply air in the kitchen is greater than the hood exhaust, you will push odors and smoke into the rest of the apartment.

Most residential hood manufacturer will give a maximum length of duct they can be connected to. With some calculations you can estimate the ESP of the fans. But is it really necessary? If the hood fans can get the air to a central shaft, then your roof fans need only be able to move air in the shaft.

How are you dealing with diversity and the fact that not all units need the kitchen hood on at all times?

 

[trashcanman]

DO NOT EVER provide fire dampers in a duct that can be exhausting grease fumes. Code prohibits this. The damper can collect grease and dust and is looking for a spark to ignite it. Grease exhaust duct (from kitchen hood) must be smooth and continuously sloped up away from the hood.