Stove Vent Values
I am remodeling my kitchen and need a new range hood that is quieter and provides more light. Are there efficiency differences among them? Does just opening a window work as well?—Diane B.
Recent advancements in the design of range hoods improve energy efficiency. In general, the most efficient range hoods are also the quietest.
Today, people are installing larger ranges, so the old range hood also needs to be replaced. Switching to a newer style of range hood, such as an island model, requires new vent ducting.
Opening a window during mild weather, when you are not using heating or air conditioning, can be effective ventilation for certain types of cooking. When just boiling water, steaming vegetables, baking breads, etc., the natural ventilation from a window can carry away the excess moisture and heat and provide pleasant fresh air.
For other times of the year, or when you are cooking greasy foods or foods with strong odors, running the range hood is more efficient and effective. Just opening a window requires much more airflow than a range hood. This increases the load on your furnace or air conditioner. Also, hot greasy droplets tend to settle out of the air before they ever reach the open window.
There are two types of range hood blower designs. Some models use a fan blade to draw out the air from above the range. This is an inexpensive design and is not particularly efficient or quiet. Better models use an efficient squirrel-cage blower design, similar to a furnace blower.
Energy Star (www.energystar.gov) has a list of range hoods that meet its energy-efficiency requirements. The efficiency of range hoods can be compared by dividing the cfm (cubic feet per minute) of airflow by the amount of electricity (watts) each uses. All of the Energy Star ones produce a minimum of 2.8 cfm of airflow per watt consumed. This includes the electricity used for the lighting built into the range hood.
The type of lighting used is as important as the blower design to reduce energy consumption. Range hoods with CFLs (compact fluorescent lights) are the most efficient and the light quality is reasonably good. You can select full-spectrum CFLs with more natural looking light quality. Many range hoods still use halogen lighting, which is not as energy efficient.
It is important to properly locate and size a range hood for maximum effectiveness using the least amount of electricity. As a rule of thumb, a maximum airflow capacity of 50 to 75 cfm per foot width of the range should be adequate. Locating the range hood about 24 inches above the range is ideal, but the height is sometimes limited by cabinets. If possible, the range hood should extend three inches over each side of the range.
If you select an efficient, quiet range hood, only two or three speeds are adequate. Models with totally variable speeds are available for people who are particularly sensitive to the noise level and indoor air quality. A high-heat safety sensor to automatically switch it up to high speed is a good feature.
For island-style range hoods, which draw a lot of air, Broan’s Best models can now communicate with fresh air ventilation controls. When the hood is running, a remote damper opens to allow a controlled amount of fresh air into the home to maintain the proper indoor air pressure.
The following companies offer efficient range hoods: Abbaka, (800) 548-3932, www.abbaka.com; Broan-Nutone, (800) 558-1711, www.broan.com; Dacor, (800) 772-7778, www.dacor.com; Imperial Range Hoods, (800) 851-4192, www.imperialhoods.com; and Vent-A-Hood, (800) 331-2492, www.ventahood.com.
