A range hood is located above a cooking surface to exhaust polluted and humid air out of the kitchen. The two primary types of range hoods are venting hoods and recirculating hoods. Venting range hoods exhaust stale air to the outdoors. They are the most effective at eliminating cooking odors and moisture from the kitchen. A recirculating range hood is less preferable. This unit filters the air through a replaceable carbon filter and returns it to the kitchen, instead of venting to the outdoors. This type does not eliminate excess moisture. Due to indoor air quality concerns, this is not a recommended option and should only be used when venting to the outdoors is not structurally feasible.
A range hood is an effective appliance at removing not only smoke and other related cooking smells from the kitchen, but also other airborne contaminants, such as oil particulates from fried food. A venting range hood can help prevent structural damage from excess moisture and ward off adverse health affects from poor indoor air quality.
It is recommended that only range hoods that are directly vented to the exterior be installed. The State of Minnesota Administrative Rule 1346.0505 on Domestic Kitchen Exhaust Equipment states:
Where domestic range hoods and domestic appliances equipped with downdraft exhaust are located within dwellings, the hoods and appliances shall discharge to the outdoors through ducts constructed of galvanized steel, stainless steel, aluminum, or copper. The ducts shall have smooth inner walls and shall be air tight and equipped with a backdraft damper. Domestic kitchen exhaust hoods ducted to the outdoors shall have makeup air provided according to IMC Section 501.4.1
To qualify for the mandatory Green Communities credit, a range hood must be vented to the exterior of the building.
The most important features to seek when purchasing a range hood are an ability to vent to the exterior and at least two fan-level settings. The low fan setting should be 100 cfm or lower with a sone level of 2.0 or lower. This ensures healthy indoor air quality and a fan option that can be self-regulated to the level of exhaust needed.
A range hood can greatly increase the indoor air quality in the kitchen by removing smoke, steam, particulates, and unpleasant odors from the area of the range. Left unvented, these can cause damage not only to the surface treatments of the kitchen, but also to structural elements. A range hood is also effective at reducing air conditioning energy consumption and costs in the summer by exhausting added heat and moisture.4
Notes on Use
It is important that the range hood match the size of the range below it. Deeper units are preferable. 17" is common, but a depth of 20" will be able to capture more exhaust from the range.
Options and Analysis
If the unit has a combined light source, ensure that the light bulbs used are compact fluorescent or fluorescent lamps. Some units have dual settings for normal usage and a dimmer setting as a night-light source.
The cost of a range hood/exhaust fan ranges from $30 to several thousand dollars. It is important to ensure that the range hood is of high quality with features (able to vent to the exterior, multiple fan speeds, appropriate air moving abilities, low sone value, etc) necessary for its application.
A range hood, pipes for venting, and the backdraft damper should be installed by a professional and to the manufacturer's specifications. It is important that future homeowners are informed of the benefits of using the range hood and any necessary maintenance they should perform to ensure proper operation.
State of Minnesota. Office of Revisor of Statutes. Minnesota Rules Chapter 1346.0505 Section 505 Domestic Kitchen Exhaust Equipment. 10 Sep 2007. 20 May 2008. www.revisor.leg.state.mn.us/rules/?id=1346.0505.
2 "Range Hoods a Consumer Guide." Home Ventilating Institute. 4 Feb. 2008. 20 May 2008. www.hvi.org/assets/pdfs/HVIRangeHood_4Feb08.pdf.
3 United States. Environmental Protection Agency. "ENERGY STAR® Program Requirements for Residential Ventilating Fans." 10 Jan 2006. 19 May 2008. www.energystar.gov/ia/partners/product_specs/eligibility/vent_fans_elig.pdf.
4 Brook, Dave. "Home, Home on the Range Hood," Home Energy Magazine Online. Oregon State University Extension Service. Portland, OR: Nov/Dec 1997. 27 May 2008. www.homeenergy.org/archive/hem.dis.anl.gov/eehem/97/971104.html.
5 Davis Energy Group, Energy Solutions. "Analysis of Standards Options for Residential Exhaust Fans." Pacific Gas and Electric Company. 27 Apr. 2004. p. 7. 27 May 2008. www.energy.ca.gov/appliances/archive/2004rulemaking/documents/case_studies/CASE_Res_Exhaust_Fans.pdf.