CKD CKD Appliances & Kitchen Ventilation 2 — Questions and Answers
Question 1: What is the recommended minimum width of a range hood relative to the cooking surface below it?
- 6 inches narrower than the cooktop
- The same width as the cooktop
- 3 inches wider on each side than the cooktop (Correct answer)
- 12 inches wider than the cooktop on each side
Correct answer: 3 inches wider on each side than the cooktop
Range hoods should extend at least 3 inches beyond each side of the cooking surface to effectively capture rising vapors and grease.
Question 2: What is the primary disadvantage of a recirculating (ductless) range hood compared to a ducted hood?
- Higher installation cost
- Cannot remove heat and moisture from the kitchen (Correct answer)
- Requires more frequent filter changes
- Louder motor operation
Correct answer: Cannot remove heat and moisture from the kitchen
Ductless range hoods filter grease and odors through charcoal filters but recirculate air back into the kitchen, unable to remove heat and moisture.
Question 3: What is the recommended mounting height range for an under-cabinet range hood above a gas cooking surface?
- 18–21 inches
- 24–30 inches (Correct answer)
- 30–36 inches
- 36–42 inches
Correct answer: 24–30 inches
Under-cabinet hoods over gas cooking surfaces are typically mounted 24–30 inches above the grates for optimal capture without creating a fire hazard.
Question 4: What is 'makeup air' in the context of kitchen ventilation design?
- Cosmetic finish on vent covers
- Replacement air supplied to compensate for air exhausted by a range hood (Correct answer)
- Filtered air recirculated through a charcoal filter
- Air used to cool the cooktop surface
Correct answer: Replacement air supplied to compensate for air exhausted by a range hood
Makeup air is replacement air that must be supplied to a kitchen when a high-CFM hood exhausts large volumes, preventing negative pressure and backdrafting.
Question 5: Which type of range hood is suspended from the ceiling above an island or peninsula cooking surface?
- Under-cabinet hood
- Wall-chimney hood
- Island (ceiling-mount) hood (Correct answer)
- Downdraft ventilator
Correct answer: Island (ceiling-mount) hood
Island or ceiling-mount hoods are suspended from the ceiling over cooktops on islands or peninsulas where wall mounting is not possible.
Question 6: What is the primary limitation of a downdraft ventilation system compared to an overhead hood?
- High installation cost
- Cannot be used with gas cooktops
- Less effective at capturing rising steam and vapors (Correct answer)
- Requires an exterior wall location
Correct answer: Less effective at capturing rising steam and vapors
Downdraft systems pull air downward across the cooking surface, but rising steam and vapors naturally move upward, reducing capture efficiency compared to overhead hoods.
CKD CKD Appliances & Kitchen Ventilation 2
What is the recommended minimum width of a range hood relative to the cooking surface below it?