Another factor is the projection of the hood, which measures how deep the canopy is from the back bottom edge to the front bottom edge. Some consumers want their hoods to be shallow so they won’t bump their heads, but it is recommended that the front edge of the canopy projects to the front edge of the burner to ensure maximum capture. Center island hoods are no exception. The canopy should not be centered over the cooking surface, but should be aligned with the front edge of the front burner.
Overlap is equally important. A range hood should overlap, so that it is wider than the cooking equipment beneath it. The hood should extend three inches wider than each side of the cooking surface. Another consideration is the mounting height – the vertical distance the canopy is placed above the cooktop. There is no magic formula, but the recommended heights are 21" to 27" for an undercabinet range hood, 24" to 30" for a wall mount design and 30" for island hoods. It is best that the hood is installed at the lowest height recommended by the manufacturer.
Know How to Vent
The power of the venting system, also known as the blower, is also important in determining the right range hood. The blower system is placed inside the canopy and is the power behind the system. But bigger is not necessarily better. Too much airflow out of the home can create a negative air pressure that can result in a dangerous backdraft. Similarly, too much power can ventilate cooking contaminants along with clean air that is paid to cool in the summer or heat in the winter. The right balance here is not too much, not too little, but just right.
And what about the noise factor? A blower system that uses increased speed of the motor to increase power will also increase the overall noise. An effective alternative is to add motors under one hood to increase the airflow rather than increase the speed (and noise) of a single motor. Either way, it is best to match the overall CFM (or airflow) of the range hood to the cooking equipment it will be placed over. Performance is more important than power. And a good blower system that adds motors to increase the airflow, combined with a good canopy, will remove the appropriate amount of vapors and contaminants most effectively and with the least amount of noise.
The power of the blower is measured in CFM (cubic feet per minute). CFM is the measurement of how much air can be removed in a single minute. Range hoods come in 300, 600 or 1200 CFM. The number chosen should correlate with the BTUs from the cooking surface. As a general guideline, 1 CFM should be used for every 100 BTU. For example, a 60,000 BTU cooktop should have a 600 CFM range hood. Electric cooktops generally are not as hot as professional-style ranges, so they would need a lower CFM, usually between 450-715 CFM. The cooking style may also determine the needed CFM. A homeowner who uses the kitchen for small, quick meals would not need as much CFM as someone who has a larger kitchen and makes gourmet meals.
The Path Well Chosen
The most overlooked element of a range hood is also one of the most crucial – the ductwork. It provides the all-important path in which the trapped contaminants are exhausted to the outside, so it needs to be done correctly. If done incorrectly, the range hood will be less powerful and efficient. Duct size should never be restricted and the duct should only be made of smooth metal. The duct run should run as short and straight as possible, with few turns. Most manufacturers recommend never exceeding 100 feet of duct run. Finally, make sure the air is not restricted at the end of the run, and it empties to the outdoors.
There are many styles of range hoods available, but selecting the right one will protect the investment of the home, add value and improve air quality, and that never goes out of style.
Blake Woodall is director of sales for Vent-A-Hood, based in Richardson, TX.
