Vent hoods are often an afterthought in kitchen renovation projects — the last appliance selected by homeowners. However, vent hoods are important:
- Functionally. They remove heat, smoke, smells, steam, and fumes from the workspace.
- Aesthetically. The vent hood sits at eye level and is the first thing one may notice when entering the room.
How much ventilation do I need? Vent hood manufacturers have various formulas for determining what “adequate” ventilation is. Use the calculator below to bound the answer!
|Fume/odor generation capacity indicator:|
|Gas stove power||Btu|
|Electric stove width||inches|
|Throughput measurement equivalency:|
|1 cubic foot per minute (cfm) =||1.7||cubic meters per hour (cmh)|
|Minimum recommended ventilation power|
|A (electric stove size)||360||612||CFM = electric stove width inches * 10|
|B (gas stove power)||400||680||CFM = gas stove btu / 100|
|C (room volume)||288||490||CMH = cubic meters * 10|
|D (room volume - alt method)||432||735||CFM = cubic feet * 15 cycles / 60 minutes|
|E (room area)||384||563||CFM = square feet * 2 [For 8-ft ceilings, this yields the same result as 15 cycles of room volume per 60 minutes]|
|F (room volume - for bathroom)||230||392||CFM = cubic feet * 8 cycles / 60 minutes|
- Noise comes from both the motor and from air movement
- More turns in ducting = more noise
- 6 sones @ 600 cfm is a reasonable noise level
- For >1000 cfm, you need at external blower. Blower should be placed beyond >12 ft ducting, for noise abatement.
- 30″ above cooking surface
- 20-24″ projection from wall
- Wood-covered hoods must be >36″ above the cooktop, which reduces their effectiveness. Metal hoods are therefore preferable.