Tips for Making Efficient Ventilation Choices

In recent years, the range hood has increasingly been occupying center stage in the kitchen, both for its aesthetic appeal and functional value. With visions of gourmet meals and family get-togethers, homeowners want their kitchens to reflect their lifestyles, and the ventilation unit makes a key statement when it comes to design, function and, of course, cost.

The range hood, being the focal point, continues to reflect and dictate the design or style of the kitchen in many cases. If the range hood is contemporary, the kitchen has a contemporary feel. If it is traditional, the room has a traditional feel. And if a colorful choice is made, then expect a bold impression.

But in conjunction with design and style, it’s important that today’s kitchen designer understands how to specify the right type of range hood for the space’s functional needs. After all, if the aesthetics are right, but the ventilation system is not right for the space functionally speaking, the kitchen that looks appealing may not smell appealing.

Add 3.5 million range hoods manufactured each year to the equation, and it can be overwhelming to even a seasoned veteran. Yet, to keep the home free from harmful contaminants, it’s the single biggest appliance decision that every designer wants to get right.

Filtering Through the Options

When making a decision, the first step is deciding on the type of filtration system within the hood. Smaller hoods typically use mesh filters to collect vaporized grease particles. Larger hoods often feature stainless steel baffle filters that collect vaporized grease particles in troughs. A third option is the filterless “centrifuge” system, which uses centrifugal force inside of a sealed reservoir to collect vaporized grease particles. This option offers increased efficiency and reduced noise. The type of filtration system chosen depends on cooking habits and noise toleration.

Another important consideration, in the design category, is the type of hood a designer selects. This is determined by the cooking equipment and the layout of the kitchen. There are three general categories of range hoods. The undercabinet hood is used for kitchens with bridge cabinets and mounts between the bridge and over the cooking equipment. The second type is the wall mount hood, which is mounted directly on the wall above the cooking equipment and may feature a duct cover that is installed between the top of the hood and the ceiling to cover the ductwork. The third type is the island hood. An island hood is used over a kitchen island and hangs from the ceiling directly over the cooking equipment.

Many hoods also offer extra features that may provide added convenience to the homeowners. For example, utensil racks, spice storage, mood lighting and heat sensors that control ventilation speed may be options to consider.

Once the filtration system and the appropriate style of range hood is selected, there are finer details to examine – details that directly impact how effective the range hood will be in the kitchen. Those details include canopy size, blower capacity and duct work, among others.

Canopy Counseling

Range hoods do not pull, draw or suck in vapors. Instead they collect the contaminants that rise up through the canopy, and then exhaust the vapors to the outside. When the vapors are not collected in the canopy, they linger throughout the kitchen. So, the size of the canopy is very important to ensure that the most contaminants are collected.

The first element to consider is the holding capacity of the canopy. The holding capacity measures the ability to capture the cooking vapors – the greater the holding capacity, the more vapors it will capture. For kitchens with professional-style cooking equipment, a holding capacity of 12" or taller is recommended.

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.