Venting Range Hood To The Attic? Here’s Why You Shouldn’t

When you consider installing a venting range hood in your kitchen for the first time you not only have to find the right range hood for your kitchen, but you’ll also have to plan the placing of the duct that will be instrumental in taking polluted air out of your home.  One of the places where the ductwork generally goes through is the attic. You’ve probably considered the possibility to let it vent into the attic instead of taking it through the roof or a wall. However, after you’ve listened to what some of your friends are telling you about the problems they’ve encountered because of their range hoods venting into their attics, you now have the question of whether it is such a good idea to vent your range hood into the attic.     

The answer to the question is easy! It is a clear “no.” You should never vent your range hood into the attic. The excess grease and moisture you will be blowing into your attic will ruin it and over time the buildup of the filth will cause mold damage as well. Instead, vent your hood through an exterior wall or the ceiling to the outside of your home.

In this article, we’ll look at how a venting range hood works and then discuss some of the most important reasons why you should never vent your range hood to the attic.

An attic

What is a range hood and how does it work?

Before we discuss the reasons why you shouldn’t vent your ducted range hood to your attic, let’s briefly find out what a range hood is designed for. 

Two main types of range hoods

Range hoods have been developed to keep your kitchen free from grease, steam, odors, and fumes while you cook. There are two main groups of range hoods available for domestic kitchens. The one group of hoods is known as ductless hoods. They are designed to suck in the polluted air in the kitchen, send it through various filters and recycle the cleaned air back into the kitchen. The polluted air is never taken out of the kitchen.

The second main group is the venting range hoods, also called “ducted range hoods.”  They are designed to pull the polluted air out of the kitchen and expel it outside your home.  In this article, we’ll only look at ducted range hoods. 

How does a venting range hood work?

Most venting range hoods are powered by a single motor, but some larger ones have two or more. The blower motors suck fumes, steam, heat and odors from your cooktop while you are cooking. The air is blown via ductwork outside your home. Because it is taking the polluted air completely out of the kitchen, this is a much more effective way of venting your kitchen than with a ductless hood.

Reasons why you shouldn’t vent your hood into the attic

The reasons why you shouldn’t vent your hood into the attic include the following: 

1. The greasy and polluted kitchen air never leaves the home

When you vent your hood to the attic it may seem as if your kitchen’s air has been cleaned and your kitchen can smell fresh. But all you’ve done is to move the greasy air, steam and odors to another part of your home. 

You’ve made it “invisible” in the kitchen but the polluted air has never left the house. The result is that your overall indoor air quality is declining. 

2. Your attic will become dirty and covered with grease and moisture

All the grease and unwanted contaminants from your kitchen air are accumulating in your attic and spread to the rest of your home. The polluted air is breathed in throughout your home. Apart from the grease and contaminants, moisture also accumulates in the artic, and all these factors may result in mold and structural damage.

In practice – if you boil a pot of water for pasta the hood’s fan pulls the steam of the boiling water into the ductwork and expels it into the attic. Then, the next dish you cook may be an Asian food creation cooked with high heat and heavy smoke. The smoke is also extracted and expelled into the attic. The steam and smoke aren’t going anywhere outside the house.

3. The insulation in your attic will deteriorate fast

The result of the steam and grease not leaving the attic is that they accumulate all over the walls and ceiling. Eventually, the insulation in your attic will deteriorate fast. The moisture that builds up, will let the wood supports decay and mold may be formed.

4. Pests could be attracted to the attic

The food particles in the expelled kitchen air may attract insects and other pests, too. If your attic is infested with pests it can be a very costly process to get them out again. 

5. It will be difficult to keep your attic well-maintained

The longer your range hood is venting into the attic, the more difficult it becomes to keep the attic clean. And if you don’t keep your attic well-maintained it becomes a health risk over time, especially if you or a family member suffer from asthma or another lung disease. 

6. Condensation in your attic might lead to water-related problems

When the warm air from your cooking in your kitchen comes into contact with the cold ductwork in your attic it creates condensation. This can build up and after a few weeks, you may have a lot of water to deal with in your attic.

In a climate where it gets below freezing, the problem escalates. The moisture may accumulate as ice and then melt all at once in spring. Your attic and ceilings can be badly damaged if this happens. 

A hint that can save you money

When you buy a house with a ducted range hood or when you have a vent installed by a company ensure that before you start using the hood you check the ductwork from the hood up to the end of the ductwork. Sometimes, contractors may forget to attach the final section of venting between the attic and the roof. Check the connections and if the duct ends in the attic, lengthen it to extend through the roof or sidewall to the outside of the house. 

Alternatives for venting into your attic

You might now wonder where else could you vent. There are two primary alternatives. The first is to expel the kitchen air through the roof itself, out into the open. This method is commonly used and an efficient way to go. 

The second method is to go with the ductwork through the wall and out at the side of your house. It is actually an easier way than to go through the roof, but you can only follow this road if your cooktop and hood are located near an exterior wall that can be used for the ductwork to go through. 


A vent hood is in most homes an essential appliance to keep the cooking environment in the kitchen comfortable and fresh. A vent hood effectively extracts the polluted air out of your kitchen, but if the ductwork carrying the air vents into your attic you haven’t solved your polluted air problem – you’ve only moved the problem to another place in your home. You are moving polluted air and moisture from your kitchen to your attic. 

Charles John

Experienced HVAC technician with 8 years of experience in the industry. Capable of handling all sorts of heating and cooling equipment as well as proficient in operational management, construction-related techniques such as preventative maintenance, electrical troubleshooting and AutoCAD

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