Core TradesQuestion 97 of 700
A large commercial kitchen exhaust hood removes a high volume of air. Without makeup air, the space goes into strong negative pressure. The BEST solution is to:
a.Provide a makeup air system that replaces the exhausted air
b.Add more exhaust fans
c.Seal all doors and windows tighter
d.Reduce the hood size only
Explanation
High exhaust volume must be balanced by a makeup (replacement) air system; otherwise negative pressure causes doors to slam, backdrafting of combustion appliances, and poor hood capture. Adding exhaust worsens it; sealing tighter increases negative pressure; shrinking the hood may not meet capture needs.
Law Reference: 2025 CA Mechanical CodePractice all 700 questions free — no signup required.
Related questions on this topic
- A vent terminating through the roof must extend a minimum height above the roof and be set back from any vertical surface or opening, MAINLY to:
- A gas furnace is installed in a small, tightly sealed closet with no combustion air openings. The MOST likely dangerous consequence is:
- CALCULATION: A common rule of thumb provides 1 square inch of combustion air opening per 1,000 Btu/h of appliance input when air comes from inside a large space. For a 100,000 Btu/h furnace using two openings (high and low), what free area does EACH opening need under this rule?
- During a split-system AC installation, the refrigerant line set is run with several tight kinks and an excessively long distance beyond the manufacturer's limit. The MOST likely result is:
- CALCULATION: A room measures 20 ft by 15 ft with a 10-ft ceiling. A ventilation system supplies 500 cubic feet per minute (CFM). Approximately how many air changes per hour (ACH) does this provide?
- A clothes dryer exhaust duct is run with several sharp bends and a long concealed length, then vented into an attic. Two problems with this install are:
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against California CSLB General Building (B) Trade Examination · How we review