Thursday, July 14, 2011

Replacing Your Ceiling Light Fixture with a Ceiling Fan? There's More to it Than You Think

More and more homeowners are replacing their existing ceiling light fixtures with new paddle fans to realize significant year-round energy savings.  In the summer, ceiling fans create cooling breezes, which reduce the strain on air conditioners.  In winter, they circulate heated air to keep the room warm.  With a variety of available styles, ceiling fans can be an attractive update for a room's overall d├ęcor. 

While ceiling fans are common installations, homeowners often overlook the safety hazards involved.  These hazards can be especially prevalent in older homes. 

First, it is important to select the correct size fan.  Here are some tips:
Use a 36-inch diameter ceiling fan if the largest room dimension is 12 ft. or less.
Use a 42-inch diameter ceiling fan if the largest room dimension is 12 to 15 ft.
Use a 52-inch diameter ceiling fan if the largest room dimension is over 15 ft.

Next, inspect the ceiling lighting box.  The majority of ceiling lighting boxes in older homes are made either of plastic or a composite called Bakelite.  These boxes are light duty, rated for fixtures only, and are often not strong enough to support a ceiling fan.  The boxes feature a plastic grooved threading for the fixture mounting screws.  Over time, plastic and Bakelite boxes can become brittle and too fragile for even a light fixture.  This is especially true if homeowners have used over- wattage lamps in the past. The heat from oversized lamps will rise and penetrate the box, eventually baking out the little moisture left in the plastic.  This causes fragile mounting threads and a less than structurally sound lighting box.

Electrical code specifically requires a ceiling mounting box that is rated by the manufacturer for use with ceiling fans and heavy chandelier lighting fixtures.  These "bracing" boxes are usually made of metal, but are always UL labeled for fan use.   More importantly, they are designed to support the fixture separately from the box.  Long bolts and screws connect to a framing member, which supports both the weight and vibration associated with ceiling paddle fans. The box serves a dual purpose – it houses the electrical connections in a safe, non-combustible environment, and the bracing design supports the fixture and its load.

There are many different boxes that meet this "bracing" requirement.  A homeowner who is going to remodel and replace an existing light fixture with a fan, or who wants to install a new ceiling fan on an open stud ceiling, must select the appropriate mounting box. 

Ceiling fan installation can be difficult.  If not done correctly, or if done with an inadequate mounting box, an improperly installed fan can lead to short circuits or even fires in the home wiring system.
A homeowner who is unsure if the mounting box is rated for paddle fan use or if it has an adequate weight rating for the fan being installed should consult a professional electrician.