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Should You Insulate Your Range Hood Ductwork? (Answered)

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If you are installing a ventilation range hood, you might be wondering if you should insulate your ducts.

Yes. You should insulate your ductwork. While it’s not required, it is recommended because ducts that leak hot air into unheated regions can add hundreds of dollars to your heating and cooling expenses

But there’s a lot more to this question than meets the eye. So, in this article, we will cover what a range hood duct is, whether it should be insulated, and show you how to insulate your range hood duct to get the most out of your kitchen ventilation system.

Editor’s note: This article has been updated on September 15th, 2021, to include additional information regarding range hood Insulation.

Can I use insulated flexible duct for a range hood?

According to the IRC, the ductwork must be made of galvanized steel, stainless steel, or copper to comply with the regulations. Its interior must be smooth and airtight, and it must be watertight. Because of this, you should avoid using a flexible product for this application, especially that flimsy, flexible plastic ducts. A  rigid ducting such as this will be more appropriate.

Advantages of Insulating your range hood ductwork

Quieter kitchen

It is recommended an insulated duct will be even quieter than a non-insulated duct

What is the best duct for venting a range hood?

The best duct for a range hood is a rigid duct. It is a low-cost and long-lasting choice for your range hood vent. This article will teach you more about rigid ducts.

If you have a high CFM range hood, you will need a larger duct. For example, if your range hood is 600 CFM, you should use 6-inch ducts. If your range hood is 900 CFM, you should use an 8-inch duct. If your rage hood is 1200 CFM, and over, you will need a 10-inch duct.

What insulation should I use?

The US Department of Energy recommends rigid fiberboard insulation for ductwork insulation. Insulation should be installed in accordance with the manufacturer’s instructions. Prior to insulating, however, seal all ductwork openings; insulating ductwork with unsealed openings is, at best, futile.

R-6.5 to R-6.8 is the highest R-value for rigid fiberboard duct insulation, which is made of polyisocyanurate foam (polyiso for short). This type of insulation features two layers of reflective foil, a foil vapor barrier on the back and a white foil finish on the front. R-values for rigid polystyrene (XPS) foam insulation are approximately R-5, while expanded polystyrene (EPS) foam insulation is approximately R-3.8.

Instead of duct tape, use mastic sealant or metal tape. Contrary to its name, duct tape does not form an effective seal and degrades rapidly.

How to Stop Condensation

If you have some condensation, do not panic. Condensation is common. Condensation forms when cool air comes into touch with warm air. It also occurs when cold air escapes through a wall or rooftop and into a duct. Condensation is more common in the winter, and it is most noticeable in colder locations. During the spring and summer, you are unlikely to have water accumulating inside your duct. If you do, it might not be condensation.

Below are a few ways to stop condensation from forming in the first palace.

1. Set up a damper backdraft.

A damper is a unit located near the outside wall or ceiling. It closes when you’re not using your range hood. This stops your duct from being exposed to cold air, waste, dirt, and small animals. Eliminating y draft which might flow across your pipeline. Preventing condensation.

2. Cap or cap on the roof.

At the end of your pipe is a roof cap or wall cap. It protects tiny animals and dirt from coming into your conduit and from entering your damper and wall or roof. It maintains the range hood duct clean, which means you won’t have to spend money on maintenance later.
It also minimizes the quantity of cold air in your house and warm air out. This reduces condensation within your vent, just like a backdraft damper.

3. Insulate your pipeline.

Insulation is an excellent way to stop condensation in a hood ventilation range. It ensures that no air leaks from your kitchen. This will keep your ventilation system running smoothly for many years to come. 

Insulation can also extend your hood’s lifespan. When cold air collides with your duct, it strikes the warmer insulation rather than the cold aluminum or steel conduit. The heated air would come into contact with the cold surface of your conduit without insulation and cause condensation.

4. Get new dampers.

If you already have a backdraft damper and are still having condensation, it is possible that it needs to be replaced. When your hood is turned off, it is possible that the damper is remaining open, allowing cold air to enter. This might be the issue. if so, the damper will need to be replaced.


How to insulate your ducts


Your air ducts are one of the most significant systems in your home and are likely to contribute to increased power costs if the conduct is badly sealed or insulated.

In this article, we covered weather range hood ducts that should be insulated. Below are some key takeaways:

Key takeaways

  • Range hood ducts do not need to be insulated but it is highly recoemnede
  • Insulated range hood ducts are quiters
  • Insulated range hood diucts help prevent condencation.

 If you’d like to learn more about range hoods, check out our full blog here. Stay safe!

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Author avatar - Roger Harris
Written By Roger Harris
Hey there! My name is Roger, and I've been selling range hoods for over six years. I now run this blog all about range hoods and kitchen ventilation! If you're looking for a new range hood for your kitchen, this is the place for you.

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