Q. I am remodeling my kitchen and need a new range hood that is quieter and provides more light than my old one. Are there efficiency differences among them? Does just opening a window work as well?
The most efficient range hoods are also the most quiet. This is because efficient blower designs move the air smoothly, which reduces noise.
Opening a window during mild weather when you are neither heating nor air-conditioning can be effective for certain types of cooking. When just boiling water, steaming vegetables, etc., the natural ventilation can carry away excess moisture and heat and provide pleasant fresh air.
For other times of year or when you're cooking greasy foods or foods with strong odors, running the range hood is more energy efficient and effective.
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 air flow by the amount of electricity (watts) each uses. Most of the Energy Star ones produce about 2.5 to 3.0 cfm of air flow per watt consumed.
The type of lighting is important to reduce energy consumption. Range hoods with compact fluorescent bulbs are the most efficient and the light quality is reasonably good. Many range hoods still use halogen lighting. This is not as energy efficient, but halogen bulbs produce a very white light easy to work under.
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 air flow capacity of 50 to 75 cfm per foot width of the range should be adequate. Locating the range hood about 30 inches above the range is ideal.
If you select an efficient, quiet range hood, only two or three speeds is adequate. Models with totally variable speed are available for people who are particularly sensitive to the noise level and air quality.
For island-style range hoods, which draw a lot of air, Broan Best models now can communicate with fresh air ventilation controls. When the hood is on, a remote damper opens to allow a controlled amount of fresh air into the home.
These companies offer efficient range hoods: Abbaka, www.abbaka.com; Broan-Nutone, www.broan.com; Dacor, www.dacor.com; Imperial Range Hoods, www.imperialhoods.com; Vent-A-Hood, www.ventahood.com.