Why is Cold Air Coming Down my Range Hood Vent? Causes and How to Fix it



Why is Cold Air Coming Down My Range Hood Vent? Understand the Cause and How to Fix it

Are you noticing cold air coming down your ducted range hood vent? A ducted vent hood uses a fan that draws steam, smoke, and odors from cooking through a duct and expels it outside. If you are experiencing a cold air draft from your range vent, we have some answers to why this might be happening and what you can do about it.

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why is my range hood leaking cold air? kitchen in the winter

Why Cold Air May Be Coming Down Your Range Hood Duct:

why is cold air coming out of my range hood when it is turned off? girl cooking under range hood

The outside vent flap or wall cap isn’t closing properly.

It is the homeowners choice to install a wall cap or exterior vent flap (depending on your range hood model). The purpose of adding a range hood vent flap to the exterior duct work is to keep outdoor air, debris, and even small insects or animals from entering the duct. It opens when the range hood is operating and closes when it's off. If this flap doesn’t close tightly, cold air can seep back into your kitchen through the range hood.

There is a problem with the backdraft damper.

All Hauslane range hoods come with a duct adapter that includes a backdraft damper which prevents outside air from entering the duct and leaking into your kitchen. The duct adapter connects the range hood to the ductwork inside of the kitchen. Improper hood maintenance and long-term use can cause grease build-up or damage to the damper and effect its function. If it's damaged or stuck, it can allow the influx of cold air.

There is negative air pressure throughout your home.

If your home is tightly sealed, turning on exhaust fans (like those in bathrooms) or clothes dryers can create a negative pressure environment. This negative pressure can pull in cold air from outside through any available openings, including a range hood vent.

The range hood is not installed properly.

If the ductwork of the range hood isn’t installed correctly there may be gaps or disjointed connections which can act as entry points for unwanted cold air.

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Why is it a Problem when Cold Air Enters Your Kitchen Vent Duct?

why is it a problem when cold air enters your range hood duct? it is cold in the kitchen and is not energy friendly

It is important to fix cold air leaking through your duct to avoid moisture build-up and increased utility costs.

  • Increased Energy Bills: The entry of cold air forces your heating system to work harder, thereby increasing energy consumption and bills.
  • Discomfort: A constant draft of cold air, especially during winter, can be uncomfortable for those using the kitchen.
  • Moisture Problems: Cold air can carry moisture which, when it meets warm air in your kitchen, can condense and cause dampness or even mold issues.

How Do I Stop Cold Air from Coming Through my Range Hood Vent?

how to stop cold air from leaking out of your range hood

Inspect the Exterior Vent Flap:

Carefully check the flap on the roof or outside wall of your home. Look out for damage, disconnecting gaps, or anything blocking the air way causing the flap to not close completely. Always take safety precautions and ask for assistance if needed. Hire a local professional if you are not comfortable with this inspection.

Inspect the Damper:

If it is damaged or not closing properly, you'll need to fix or replace it. Check for a sticky damper. If you notice heavy grease build-up, you can use a cleaning solution and soft cloth to clean it. Make sure that you keep up on regular hood cleaning and maintenance to manage gunk build-up over time.

Ensure that there are no loose screws effecting how the damper works. If there are problematic screws, tighten them or re-screw them in a location far enough away from the damper to fix the problem.

Seal any Ductwork Gaps:

Ensure that all the ductwork connections are sealed properly on the interior and exterior points of the ductwork. You can seal gaps using metal tape, foaming insulation spray, or mastic sealant. You do not need to remove any existing sealant and may build up the sealant over top of any current filler. 

Balance Your Home's Air Pressure:

You can do this by installing a makeup air system or slightly cracking a window when running multiple exhaust fans.

Consult a Professional:

If you’ve tried the above solutions and still face the issue, it's a good idea to consult a professional to inspect your range hood system and your home's overall ventilation.

Overall, a properly functioning range hood should not let in cold air.

a properly functioning range hood should not leak cold air. couple cooking in the kitchen with their new good range hood

If you're experiencing this issue, the reasons could range from a malfunctioning flap to more complex air pressure issues in your home.

Addressing the problem not only ensures comfort but also ensures that your range hood operates effectively, maintaining a healthy and pleasant kitchen environment.

Ducted Range Hoods

From Hauslane

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