Outside Dryer Vent Cover: A Complete Guide to Choosing the Right One

An outside dryer vent cover is a critical element of a dryer ventilation system. This cover allows the transfer of dryer exhaust air to the outside of the house and prevents the entry of undesirable items into the dryer vent duct. Uncovered dryer vent terminations allow pests to enter the house and can cause moisture damage to the building structure. Aesthetics and price should not be the only considerations when selecting a dryer vent cover.

Outside Dryer Vent Covers

An outside dryer vent cover is also known by a number of other names, including dryer vent cap, wall cap or exhaust hood. The cover is placed at the conclusion of the dryer vent duct, which is usually located on an external wall of the house. Most residential dryer vent ducts are 4 inches in diameter. Termination of the dryer vent should be done using a special fitting that is designed for dryer exhaust and that has a back draft damper.

The back draft damper is closed when the dryer is not in use and opens during a drying cycle to allow air and moisture to be exhaust outside the house. The back draft damper helps in sealing the duct to prevent the entrance of outside air into the dryer duct.

Start With the Dryer Vent Size 

The importance of determining the correct diameter of the duct will become apparent during the discussion of the various components of the exterior dryer vent cover. A standard residential clothes dryer uses a 4-inch duct, however, there may be covering installation issues if it is assumed that the previous cover was also a 4-inch cover. The dimensions of the mounting projection, the location of the mounting screws, and the size of the wall opening must also be checked.

There are a few drawings of the covers that illustrate the rear of the mounting plate and therefore demonstrate compatibility with the existing duct. Face dimensions are not sufficient to determine mounting plate compatibility.

Choose a Cover With Proper Airflow 

Some covers may also obstruct the flow of exhaust air and increase drying times. Louvered covers may provide better air flow, but may also collect lint, and therefore increase resistance to air flow. A hooded cover also provides better protection from the elements because the opening faces down.

Metal vs. Plastic Dryer Vent Covers 

There are a couple of considerations when choosing the material of your dryer vent cover. For one, the material has to be able to withstand the elements, especially if the cover will be mounted externally. For dryer vent covers, steel and aluminum are the more common choices for metal covers. Plastic dryer vent covers tend to be much less expensive; however, they do not withstand the elements well. Especially if the cover will be mounted externally, Plastic covers can become brittle and break.

There are other things to consider when looking at metal dryer vent covers. These include, gauge of the material, the finish, seams and the hinges.

Avoid Fine-Mesh Screens on Dryer Vents 

When it comes to dryer vent covers, an open vent is better than a blocked vent. Screens on dryer vent covers may seem like a good way to block bird and insect entrance, but the screens can obstruct the vent, reducing air flow and forcing the dryer to work harder to vent. A good damper will provide an adequate barrier to the outdoors, allowing exhaust to vent freely.

When a dryer vent cover has a damper, check to make sure that the damper is fully closed.

Check the Damper Before Installation 

The damper of an outside dryer vent cover should allow the flap to close when the dryer is off and allow it to open when the dryer is on. It should also be free to move. Check the hinge for corrosion and binding, and check for play and lint buildup. An damaged damper allows wind and water to enter the dryer vent.

The exhaust of the dryer should also be terminated outside in an appropriate location. Clearance and building requirements should be researched, as well as the requirements of the dryer’s manufacturer.

Conclusion

Choosing the right outside dryer vent cover requires attention to duct size, mounting dimensions, airflow, material, damper operation, and resistance to outdoor conditions. A properly fitted cover should allow dryer exhaust to leave the house freely while limiting the entry of outside air, pests, moisture, and debris. Regular inspection also helps identify lint buildup, corrosion, cracks, or damper problems before the cover affects the performance of the dryer vent system.