It’s called a “duct termination” in the “Clothes Dryer Exhaust” section of the International Residential Code (IRC) and the Residential Edition of the Florida Building Code (FBC). Here’s what is specified:

1. Termination of the exhaust duct must be outside the building.
2. Termination should be in accordance with the dryer manufacturer’s instructions.
3. If no duct termination location is specified by the manufacturer, then it must terminate a minimum of three feet from any opening in the building.
4. The termination must have a backdraft damper
5. The termination cannot have a screen.

   So requirement #1 means that any indoor bucket-type device to catch dryer lint and condensation is not acceptable. Flaps that self-close by gravity or a configution with a U-shape end meet standard #4. 

    But #5 eliminates approval of the protective coarse screen cover, sold as a “bird guard,” like in the photo above. It's an obstruction that catches lint, and one manufacturer of this type of dryer vent termination acknowledges the problem with a warning that you should “check periodically and remove lint or other debris, if present.” The intention of the code is to avoid any design that would trap lint and allow it to build up to start a fire. Fire departments in the U.S. respond to an estimated 14,000 fires each year started by clothes dryers.

    Also, see our blog posts How do you inspect a dryer vent? and What is the maximum length for a clothes dryer vent?

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Here’s links to a collection of some of our other blog posts about APPLIANCES: 

• What are the building code requirements for installing an appliance (furnace, air handler, water heater) in the attic?

• Which house appliances need a dedicated electrical circuit? 

• Is a washing machine drain hose required to be secured at the standpipe?

• When was GFCI-protection for kitchen dishwasher receptacle outlet first required? 

• Why does venting a clothes dryer into a garage, attic, or crawl space cause problems?

• Does a refrigerator water supply line require a shutoff valve behind it? 

• My spa tub stopped working. What's wrong?

• What is the maximum recommended height above the floor for an above-the-range microwave?

• Why would a home have natural gas appliaces but no gas meter? 

• Is a hot water faucet required at a washing machine?

• Can I remove a 240-volt range receptacle and hard-wire the range? 

• Can a dishwasher be wired to a kitchen counter small appliance receptacle circuit?

• Why is it bad to have a clothes dryer vent near an air conditioning condenser (outdoor unit)? 

• Do home inspectors test the appliances?

• What are the most common defects with over-the-range microwaves?

• Are a range and refrigerator required kitchen appliances for a house to pass FHA inspection? 

• Why are my ceiling fan blades drooping?

• Why is there a water hose connected to the back of the clothes dryer?

    Visit our APPLIANCES page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.