Commercial Kitchen Ventilation (CKV)

Sizes one commercial kitchen exhaust hood from the appliances under it. Thirty-one lines are available; each takes a cooking appliance and its linear length, and the heaviest duty category under a single hood sets the rate for the whole hood. The hood runs a foot longer than the equipment, which is the 6 in. overhang the 2020 FMC and 2018 IMC Section 507.4 require on each open side. Each hood needs its own analysis.

Two exhaust volumes are reported and they answer different questions. The code volume is 2020 FMC and 2018 IMC Table 507.5.1: one cfm per linear foot of hood for the hood style chosen and the heaviest duty under it, times the length of the hood. The ASHRAE volume is the band the 2019 ASHRAE Handbook, Applications, Chapter 34 gives, and it is set by the widest band any one appliance needs rather than by the heaviest duty, so the two are not obliged to bracket each other. Make-up air is a percentage of the exhaust beside it and is optional. Table 507.5.1 is unchanged between the 2018 and 2021 editions of the IMC.

Both tables are read straight off the workbook and nothing is interpolated. A zero rate is the code table's own “Not allowed”: an eyebrow hood over heavy- or extra-heavy-duty equipment, or a backshelf/proximity/pass-over hood over extra-heavy-duty, and the exhaust line then reads Hood Type Not Allowed instead of a volume.

A dishwasher is ranked differently depending on which line it is typed on, and that is kept as published. The first line ranks a dishwasher above every other duty, which flattens the whole hood to 100 cfm per linear foot; every line below the first ranks it as light duty, leaving its own dishwasher branch as unreachable code. A 30 in. hot-top range beside a 30 in. dishwasher under a wall-mounted canopy gives 600 CFM with the dishwasher on line 1 and 1,800 CFM with it on line 2. Note 7 prints either way and says the hood has been designed as though every appliance were a dishwasher, which is true of only the first answer. Neither answer is right in general — 100 cfm/ft under-ventilates the range and 300 cfm/ft is not what a dishwasher needs — and nothing published says which the sheet meant, so it is left alone. Put the dishwasher under its own Type II hood and size it as its own calculation.

All thirty-one lines are shown at once. The published page reveals them one at a time as the Other Equipment box on the line above is ticked, and that box also decides whether the line below it counts towards the ASHRAE band; here the boxes start ticked, so a line that has been filled in counts. Clear one to reproduce the published page with that box unticked. The code exhaust volume never depended on the boxes.

The make-up air list runs 0 to 100 percent and skips 52, as published. The workbook also carries Dishwasher as a hood description, a flat 100 cfm per linear foot whatever is under it, which the published dropdown does not offer and neither does this page. The Project Name box is dropped: nothing on the page reads it, and there is no printable layout here for it to appear on.

Corrected 2026-09: a length typed in scientific notation used to be dropped from the equipment total with no sign that it had been, and an empty first length box used to be read as text rather than as zero. A 1000 in. griddle entered as “1e3” published a blank hood length and 0 CFM of exhaust where “1000” published 84.333 ft and 25,300 CFM. Reading every box the same way is also why the exhaust line now prints 0, rather than Hood Type Not Allowed, when the first line has no length in it, which is what the workbook prints.