Problems with AHUs

[terthong]

Hi all, would appreciate if anyone can help solve my queries.

Currently, i have got a AHU located near to my Kitchen Exhaust Fan. And i have receive complaint from the tenant that the room (whereby the AHU supply air to) is giving out strong food odour, and i have actually closed up my outside air intake (fresh air damper = 0%), leaving with supply air intake flow = return air intake flow. However even using this method, the smell still surfaced. Could using of HEPA filter solve my problem? Please advise.

Thank You.

[Magoo]

Hi Terthong.
Your extract system requires fat separation filters that require cleaning daily, as well carbon filters to absorb as much adour as possible after the fat separation filters.They can or should be cleaned daily as well, and replaced regularly.
Hepa filters will block totally in a few hours, so disregard them.

[S.M.Gokhale]

Hi,
You may have closed the fresh air intake of the AHU but the AHUs are not leak tight. So it may be absorbing some air discharged by the kitchen exhaust fan.

A permanent solution is to relocate the AHU.
If this is not possible, seal all joints of the AHU with a good quality silicon sealant to prevent air ingress in the AHU.

[fixit]

Hello terthong
Try puting an duct extension on your kitchen exhaust away from the AHU fresh intake or an extra duct on the freshair intake of the AHU to take fresh air further away from the kitchen exhaust fan.

Fixit