Tips for successful operation
Consider Ventilation First
Consider ventilation requirements first when designing the kitchen to simplify duct installation and application issues. Remember that ventilation removes the airborne particles to the outdoors. Recirculation filters catch some particles in the immediate cooking area, but vapors and moisture remain inside the house.
Observe and Address Cross-Currents
Cross-currents can affect range hood capture ability. Windows, patio doors, ceiling fans, forced heating registers and garage entry doors are prime sources of cross-currents. Design in features that block crosscurrents from moving directly over the cooking surface to improve range hood effectiveness.
Range Hood Ducting
Start by selecting a termination point on the roof or wall and create the shortest possible duct path with fewest turns back to the hood location(s). Keep in mind bigger duct is better. Next determine what the largest duct size is without constriction. Now consider hoods with this size (or area) duct connection. Smaller ducting will sacrifice performance and increase sound levels. When planning termination at the hood note that some hoods allow duct attachment through the top or back of the hood.
To Achieve Peak Exhaust Rates at the Lowest Sound Levels
- Never make the size or area of the ductwork smaller than the size that originates at the hood.
- Bigger ductwork is better.
- Keep duct length less than 50 linear feet.
- Minimize use of elbows and transitions (4 or less).
- Always separate 90° elbows with at least 2 feet of straight ductwork.
- When using a remote exterior blower, using one 90° elbow will reduce noise transmission into the hood
- Place transitions at least 1 foot from the hood outlet or remote blower inlet.
Sizing the Range Hood
Use the following guidelines to help determine sizing:
Determine if the cooking equipment will be conventional (cooktop less than 60,000 BTU) or high performance (over 60,000 BTU)
To reach a starting point use the following formulas or use the cooktop manufacturer’s recommendation:
Under 60,000 BTU: 100 CFM per foot of cooktop width. Example: 36" wide wall application indicates a need for 300 CFM
Over 60,000 BTU: 1 CFM for each 100 BTU output of the cooktop. Example: 60,000 BTU indicates a need for 600 CFM
If there is a grill or griddle in the cooktop add 200 CFM to the estimate. Example: 60,000 BTU = 600 CFM + 200 CFM for grill = total 800 CFM
For island installation, more CFM is needed. For conventional cooktops use 150 CFM per foot of cooktop, and for high performance cooktops add 100 CFM to the estimate.
For the quietest possible operation, choose a model with the highest CFM, even if it is more than needed. This will allow the hood to be operated at lower normal speeds where sound can be 50% quieter with appropriate duct size.
Determining Adequate Capture Capability
The capture area of the range hood is typically defined by the outer most perimeter of the hood bottom. The “SUMP” is the inverted area of the hood bottom that acts like a container to hold the inrush of heat and smoke until the blower can drain it away, preventing smoke from spilling over the edge. If at all possible, select range hood designs that have at least a 1" deep sump. For high-performance cooktops select a model with an increased sump size. If that is not possible, increase the CFM.
Unit Dimensions Used Within This Web Site and Manufacturer's Catalogs
When designing aesthetic complements to your BEST range hood (custom cabinetry, tile, shelving, etc.) or aligning permanently affixed elements before the range hood is installed, be sure to have the product in hand first in order to double-check measurements and positioning. Unit dimensions for products within this web site and manufacturer's catalogs are subject to normal manufacturing tolerances.
A. Height: 24"–30" above the cooking surface is typical.
B. Width: Minimum hood width should match the width of the cooktop.
C. Depth: Minimum hood depth should cover
All range hoods have a recommended range of installation height over the cooking surface. The lowest level is the distance the hood was safety tested for by UL. The upper limit is a recommendation that will provide satisfactory capture. If the hood is installed below the lower limit it could cause damage to the hood and an inspector could force a reinstallation. Going above the upper limit is the installer’s choice and will have no effect on the hood, but may result in reduced capture of smoke. If the hood is above the upper limit, add 100 CFM for every 3" above the recommended height, and increase the width of the hood so it extends 6" beyond the cooktop.
Determining Range Hood Coverage
At a minimum, the range hood width should extend to the width of the cooktop, and cover 100% of the back burners and 50% of the front burners. Range hoods can be wider and deeper, and in some places it is code to have the width of the hood extend 6" greater than the cooking surface. For even better effective coverage, install the hood at the lowest recommended height and select a hood with at least a 1" deep sump in the bottom of the hood.
Range Hood Filters
Filtration keeps more of the grease by-products out of the hood and duct system and in the filter, which can be removed and easily cleaned in the dishwasher. Baffle filters are good choices for grilling or frying, but must be operated at high speed to get the best filtering results. Mesh filters work well regardless of the hood speed, allowing effective, quiet operation. New baffle-style Evolution™ filters combine baffle and mesh features for the best of both worlds.
BEST range hoods are designed for use with indoor residential cooking products, except when noted for outdoor use, but are not for use with charcoal grills of any kind.
Stainless Steel Types
BEST® range hoods utilize two stainless steel grades: Marine Grade stainless steel is recommended for protected outdoor applications, and installations along saltwater coastal areas. This type of stainless steel resists the effects of corrosive environments. Standard Grade stainless steel is suitable for all interior installations.
The accuracy of CFM claims in the marketplace is most certainly questionable. BEST® is committed to providing accurate CFM ratings based on standardized testing. BEST® product is tested by Broan-NuTone® for airflow performance using the ANSI/AMCA 210 Standard which is equivalent to the Home Ventilating Institute HVI 916 - Procedure for Air Flow Testing. Our range hoods are also tested for sound performance using the ANSI S12.51 Standard, which is equivalent to the Home Ventilating Institute HVI 915 - Procedure for Loudness Rating of Residential Fan Products.
BEST® is a registered trademark of Broan-NuTone® a proud member, in good standing, of the Home Ventilating Institute Advancing the Value of Residential Ventilation for Healthier Living.
Technical and installation documents are available online at BESTrangehoods.com, or through our Customer Service Department at 800-558-1711.