Range Hoods, to Vent or Not to Vent?

Q: I am remodeling my kitchen, and my contractor friend told me that all new homes have range hoods vented to the outside. Should I replace my recirculating range hood with one that is vented outside?

A: It depends. Installing a vented range hood should be a priority if you have a gas cooktop or oven. When in use, gas ranges exhaust water vapor and gases such as carbon monoxide. You don’t want either lingering in your kitchen causing mold or making you feel sick.

If you have an electric range, a vented range hood is a terrific investment, but the decision to install one should be based on your cooking habits and remodeling budget. If most of your meals are cooked on the range and you often feel the need to open a window to remove a lingering aroma or steam buildup, a vented range hood would be a great investment. I am grateful for my vented range hood when it removes steam on hot summer days and during culinary disasters like burnt cookies or a sweet potato pie overflowing in the oven.

Whether you own a gas or electric range, assess your current range hood by answering the following questions:

  1. Does the range hood vent outside? Range hoods are vented up through the roof or out through an exterior wall. Look for a metal duct going through the cabinets above or an exhaust cap on the exterior wall behind the range hood. You should feel air being blown out of the exhaust cap on the roof or wall when the fan is running.
  2. Does the range hood suck enough air? With the fan on, an 8½ x 11 sheet of paper or a page from Carolina Country magazine should easily be held against the fan filter by air suction. If the fan doesn’t suck enough air, the problem could be solved by repairing the fan or improving the ductwork.
  3. Can the existing range hood be vented? Nearly all residential range hoods can be installed as recirculating or vented. Consult the installation instructions, or with the fan OFF, remove the filter and look for “knock-out” spots. These are rectangular or circular panels that can be removed to allow a duct to be attached above or behind the hood.

If you are converting an existing recirculating range hood to be vented, the recirculating exhaust location will need to be closed. The location is typically at forehead height. Instead of air blowing out at your forehead, it needs to be sent through the newly installed vent to the outside.

If you are purchasing a new vented range hood, select a fan that is rated for pulling a minimum of 120 and a maximum of 600 cubic feet per minute (CFM). Too much ventilation from a residential range hood can cause problems, such as a gas fireplace backdrafting. Get product recommendations from friends and heed customer reviews. Microwaves are also available as vented range hoods.

Follow manufacturer instructions for range hood installation, height and maintenance. Range hood ducts should be sheet metal and routed as short and straight as possible. Length and turns will limit the ability of the range hood to adequately pull air. Duct joints need to be properly sealed, and the vent cap needs to open easily. Exhaust should never be ducted to an attic or crawl space.

Improving a range hood is a great consideration during any kitchen remodel project!

This article was originally published in Carolina Country Magazine.