Proper kitchen ventilation is the key to removing cooking smoke and odors from any home, especially in tightly built dwellings that include high-performance cooktops and ranges. Here are 10 expert ventilation tips that designers should consider for new and remodeled kitchen projects.
1. Vent the hood outdoors whenever possible so smoke and odors can be thoroughly removed from the home. This is the only way to guarantee removal of very tiny particulate matter, which can be 100 times smaller than a human hair.
Although recirculating fans also remove odors and particulate, they can recirculate up to 70 percent of the particulate back into the house. But like vented models, recirulating fans still provide a measure of odor filtration, protection to surrounding cabinets and additional lighting.
- For standard or conventional cooking equipment (less than 60,000 Btu for gas or electric cooktops), specify 100 CFM for every 1 foot of width of cooking surface. For example, a 30-inch cooktop requires 250 CFM.
- For high-performance gas cooking equipment (more than 60,000 Btu), use 1 CFM for every 100 Btu. For example, 60,000 Btu requires 600 CFM.
- If the cooktop contains a grill, add 200 CFM to the total required.
- If the hood is rated at more than 300 CFM, the project may require a make-up air damper depending on local codes.
If quiet operation is paramount, consider specifying an oversized blower. For example, 300 CFM might be adequate for the cook’s needs, but a range hood rated at 400 CFM produces less noise at a lower speed while providing 300 CFM. For even quieter operation, choose a hood model with a remote blower. Finally, select an HVI-certified hood to ensure that the CFM and Sone levels match the manufacturer’s claim.
3. Select a range hood that adequately covers the cooking surface. At a minimum, the hood width should be equal to the width of the cooking surface, and the depth front to back should cover the rear burners and at least 50 percent of the front burners.
For clients who are avid cooks, consider installing a range hood that is 6 inches wider than the cooktop. So, a 30-inch-wide appliance would be paired with a 36-inch-wide hood.
4. Position the hood above the cooktop as close as possible to the manufacturer’s recommendation to increase smoke and odor capture while allowing adequate access to the cooktop.
5. Reduce drafts around the cooking surface that can blow smoke and heat away from the cooktop by eliminating ceiling fans and reducing drafts from windows or patio doors.
6. Install a duct that is equal to or greater than the size on the hood. Duct size is critical to the hood’s performance, so be sure the installer specs the proper size and does not crush the duct during installation. Also, you can increase the duct size above the manufacturer’s instructions to boost the fan’s performance and reduce noise.
7. Prevent air dams that can occur when elbows are positioned too close together or when using sharp transitions. Keep 90-degree elbows at least two feet apart; if that’s not possible, install a much larger duct size. Likewise, request that the installer install gentle duct transitions, which also prevent air dams and turbulence.
8. Make sure that the back-draft damper opens and closes freely at the range hood. Inspect existing roof and wall caps to make sure that nothing prevents damper movement.
9. Install a make-up air damper in tightly built homes. Make-up air dampers ensure that there is adequate air supply throughout the home to allow the range hood to exhaust smoke and odors efficiently. They can be interlocked with the range hood and open automatically when the hood is turned on.
10. Consider convenience features that make meal preparation easier, like lights, timers and remote controls. Halogen is the most popular bulb type for range hoods because of its inherent brightness; LED bulbs are gaining popularity but high temperatures make most LEDs inappropriate for hoods. As the technology improves to accommodate higher cooking temperatures, consider LEDs designed for hoods that offer longer life spans and higher energy savings than halogens. Finally, remote controls make accessing the hood easy, and built-in timers provide added convenience.