Range Hood Duct Size

The minimum duct size for a range hood is 4", which is ideal for range hoods 400 CFM and under. The higher the cubic feet per minute, the larger the duct you'll need. At 600 CFM, the minimum duct size is 6". At 900 CFM, the minimum duct size is also 6". Finally, at 1200 CFM and above, consider a 8" or 10" diameter duct.

It is not recommended to reduce duct size. This typically decreases the efficiency of your kitchen range hood and wear out the motor prematurely by restricting the flow of air as it travels through your ductwork.

In rare cases, only if the ductwork is several inches larger than necessary, will your ductwork need to be reduced. Ductwork that is too large will drastically reduce the velocity of air as it moves to the outside of your home. It may not reach the exterior of your home.

But, this is highly uncommon. It's more common that ductwork is too small and restricts the flow of air. For that reason, it is highly recommended to purchase larger ductwork rather than smaller ductwork.

One common concern we hear from customers at Proline is that their kitchen hood is not running efficiently. This is often because their ductwork is too small given the CFM of their range hood. If your ductwork is even an inch or two smaller than we recommend, you will notice a decrease in the performance of your hood.

If you are dealing with ductwork for your new hood that is smaller than we suggest, we recommend replacing your ductwork with a more appropriate size or converting the vent hood to recirculating.

But, you should always vent outside if possible and only install a recirculating hood in your kitchen as a last resort.

The general consensus is that a round duct is more efficient and cost-effective than a rectangular duct. Air systems with round ducts have less air resistance because they use significantly less metal than rectangular duct systems. This also means that round duct is the cheaper option.

We don't recommend using PVC duct for your range hood. It's not nearly as durable as aluminum or stainless steel ductwork. You should also avoid flex duct for your range hood; it won't last very long!

Read more about what type of duct is best for your hood in this article.

If you've already purchased your hood, you are probably here because your kitchen range hood is not running efficiently. This could be due to a greasy range hood duct. Unfortunately, cleaning this duct can be quite expensive and requires professional assistance. For a complete guide on duct cleaning for your kitchen fan, click here.

To avoid the hassle of duct cleaning altogether, remember to clean your filters every three to four weeks depending on your cooking habits.

That depends on your kitchen setup. If you currently have ductwork in your home, the most affordable option is to use the existing duct. Expanding your duct system will cost more money for installation. Also, you might not have the room to expand it, if electrical wires or studs are in the way.

Consult a licensed contractor to ensure you make the right decision on your range hood duct system. If you have questions, we'd be happy to talk with you about what expanding your existing kitchen hood system might look like. Give us a call at 877.901.5530.

Some range hoods have rotatable blowers, which allow you to vent horizontally through a wall or vertically through a wall or the ceiling. With a rotatable blower, you can convert the hood from horizontal to vertical venting. But, if the ductwork is already installed, this is not recommended. It can be quite expensive to rearrange the ductwork.