Greenheck Fan 452413 manual Balancing the Kitchen Exhaust System, A. Exhaust, Nominal Filter Size

Balancing the Kitchen Exhaust System

A.To determine the proper dining room air balance:

1.Refer to engineering drawings to determine total exhaust CFM from dining areas. (Exhaust fans, heating and air conditioning units, restrooms, etc.)

2.Determine the total CFM of make-up air supplied to dining area.

3.Subtract #1 from #2 above. If the result is a negative number, a negative pressure is present in the dining area. In this case, kitchen exhaust odors could be drawn from the kitchen to the dining area. Therefore, exhaust or supply air should be adjusted to provide a slight positive pressure in the dining area.

B.To determine proper kitchen air balance:

1.Refer to engineering drawings to determine total exhaust from the kitchen area. (Exhaust hoods, dishwasher hoods, etc.)

2.Determine total CFM of make-up air supplied to kitchen area. (Make-up air hoods, heating and air conditioning units, etc.)

3.Subtract #1 from #2 above. The result should be a negative number. If the result is a positive number, a positive pressure is present in the kitchen area. Kitchen odors could be forced into the dining area. Also, a positively balanced kitchen area can adversely affect the performance of the exhaust hood.

Caution: According to NFPA 96, Ch. 8-3 Replacement Air: Replacement air quantity shall be adequate to prevent negative pressures in the commercial cooking area(s) from exceeding 4.98 kPa (0.02 in. water column).

Testing Hood Air Volume

Baffle Filter Style Hoods

A. Exhaust:

With all the filters in place, determine the total hood exhaust volume with a rotating vane anemometer as follows:

1.All cooking equipment should be on.

2.Measure the velocities

Velocity measurements should be taken at five locations per filter. These must be over a filter slot as in Fig. 29.

Nominal Filter Size
x		x	H/4
	x		H
x		x	H/2
			H/4
Fig. 29

18 Canopy Hood

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