Should Range Hoods Be Vented Outside?

When you cook in your kitchen, odors inevitably occur. You might accidentally burn something. Even pleasant kitchen scents can permeate throughout the house. Even when you turn on your range hood, the smell doesn’t disappear. Should your kitchen range hood be vented outside of your home? If you vent it outside, will that address the food odor problem?

South Central Services has insulated hundreds of homes with spray foam. Before becoming insulation professionals, we worked in refrigeration and HVAC. Many homes have vents terminating in problematic areas, which we sometimes help address when installing insulation in an attic or crawl space.

By the end of this article, you will understand:

• Why range hoods should be vented outside
• What happens when vents don’t terminate outside
• How to redirect your range hood outside of your home

Don't have time to read right now? Check out everything you need to know at a glance.

Hot And Humid Air Should Be Vented Outside.

Your stovetop is not the only place where undesirable air can be found. Hot and humid air comes from many places in the house, including the bathrooms, kitchen, and clothes dryer.

In theory, vents take hot and humid air from these rooms and transfer it outside. The steam from your shower gets sucked into the fan in the bathroom ceiling. The moisture from your drying clothes exits through the dryer vent. Steam and food odors should leave your kitchen via the range hood.

The purpose of vents is to dump hot, humid, and smelly air outside of the home so it doesn’t disturb you or your house.

What Happens When Vents Don’t Terminate Outside The House?

If your kitchen range hood doesn’t exhaust unpleasant air outside, then where does the air go?

The results depend on how your vents are currently set up in your home. However, several consequences can arise from vents not terminating outside.

1. Humid air circulation
2. Physical discomfort
3. Mildew, mold, and wood rot

Let’s examine each of these issues in more detail.

1. Vents Can Circulate Humid Air Throughout The Home.

One popular range hood design for kitchens is the microwave range hood. With the press of a button on the microwave, the range hood below comes to life. Unfortunately, microwave range hoods do not always vent dirty air outside the house. Microwave range hoods can be installed to either recirculate the air or vent it outside. It is important to vent microwave range hoods to the outside.

Otherwise, microwave range hoods will circulate the smelly, humid air throughout the house. When you push the button on your microwave, the system will distribute dirty air to the rest of your home.

While the recirculation solution may seem better than concentrating all of the odor or moisture in one area in the house, microwave range hoods are still an imperfect solution to humidity management.

If your home has a microwave range hood, you may also face home discomfort.

2. Unchecked Humidity Makes Homes Uncomfortable.

If you’ve ever stood outside on a humid summer day, you understand the physical discomfort of excess humidity. We can endure a variety of environments, but we prefer a small range of temperatures and humidity.

Depending on the time of year, your home's ideal relative humidity levels would be 55% to 60%. When hot and humid air circulates throughout your home, both the ideal temperature and the ideal humidity level are disrupted.

Your clothes feel stifling. Sweat glistens on your forehead. Cranking the AC helps but doesn’t provide immediate or lasting relief.

If you want to avoid facing excessive humidity in your home, your kitchen range hood should vent directly outside.

3. Excess Moisture Can Lead To Mildew, Mold, And Wood Rot.

What if you don’t have a microwave range hood? You’ve checked your kitchen, and you’re sure a vent carries the offensive odors and humidity away from the stove.

While you may not deal directly with home discomfort, your range hood can still cause problems in your home.

When range hoods do not exhaust outside, they are commonly set up to dump air into the attic. Over time, this concentrated moisture in one area of your home can cause mildew or mold growth.

Vents that do not terminate outside simply transfer the moisture concerns from one area to another. In the worst cases, the kitchen humidity can cause wood rot on the underside of your roof.

Mildew, mold, and wood rot are serious and expensive consequences of improper venting.

Where Can My Kitchen Range Hood Be Redirected?

The good news is that your kitchen range hood can be redirected through several areas in your home to terminate outside.

We recommend directing your kitchen exhaust through a wall, roof, or soffit. Depending on the location of your kitchen in your home, one of these may be more desirable than the others. It is vital that the vent terminates outside of the house and not within one of these areas.

Pumping excessive humidity and heat into your walls or roof will lead to the mold and wood rot we discussed earlier.

Can I Fix My Kitchen Range Hood By Myself?

If you’d consider yourself handy, you may be able to fix the kitchen range hood by yourself.

Microwave range hoods that don't vent outside should be replaced and may require more intensive, specialized labor. However, if you can find where your range hood is currently venting to, you may be able to address that on your own.

If you’d prefer to have your vents fixed by a professional, we recommend contacting an HVAC contractor or electrician to handle the rerouting. Before calling a contractor, do some investigating in your home to determine the issue with your kitchen range hood.

The Bottom Line About Why Range Hoods Should Vent Outside

The kitchen is one of the most important rooms in a home. Steam and food odors are often generated when creating delicious meals. The purpose of your kitchen range hood is to direct these smells and excess humidity outside of the house.

Range hoods that do not direct air outside can cause physical discomfort from humidity or even contribute to mildew, mold, and wood rot. Whether your range hood is currently recirculating humidity or dumping it into your attic, neither is a solution. Your kitchen range hood must exhaust dirty kitchen air outside the house for the health of you and your home.

Now that you understand why kitchen range hoods should vent outside, your next step is to:

• Learn how insulation and HVAC work together for indoor air quality
• Discover if your home could be made more comfortable with new attic insulation
• Determine whether your home could benefit from a home energy audit