Hobart AM14C ML-110977, AM14 ML-110976 manual Rate of Exhaust Flow Calculations

NOTE: Any listed and labeled factory-built commercial exhaust hood tested in accordance with UL Standard 710 by a nationally recognized testing laboratory, should be installed according to the terms of its listing and the manufacturer's installation instructions.

RATE OF EXHAUST FLOW CALCULATIONS

Based on the 1996 International Mechanical Code.

The Rate of air flow required for a vent hood is calculated using the following definitions (Fig. 6):

Q= Rate of Air Flow in Cubic Feet Per Minute or [ CFM ] Required for the Hood.

A = Area of Hood Opening in Feet2 = (L x W)

D= Clearance Height = Distance in Feet from lower lip of hood to top of dishwasher chamber.

➤				➤
				WIDTH
CLEARANCE	➤	LENGTH	➤
			➤
HEIGHT
➤

P = Perimeter of Hood that is Open. This
depends on the hood design, as follows:					Fig. 6
		Perimeter Calculation Formula
	Hood Design		Corner	Wall	Island
	Number of Open Sides		2 Sides Open	3 Sides Open	4 Sides Open
	P =		L + W	L + W + W	L + L + W + W
	Dimensions		Feet	Feet	Feet

If there are four open sides (Island Design), the calculation of the Rate is as follows:

Q = 75 x A

If there are three or fewer open sides, the calculation of the Rate is as follows:

Q = 50 x A

As an alternate method, the Rate can be calculated as follows:

Q = 50 x P x D

Example:

L = 3	W = 3	D = 2
			Rate Calculations
	Hood Design		Corner	Wall	Island
	Number of Open Sides		2 Sides Open	3 Sides Open	4 Sides Open
	Q = 75 x A				675 CFM
	Q = 50 x A		450 CFM	450 CFM
	Q = 50 x P x D		600 CFM	900 CFM	1200 CFM

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