Ceiling Fan Installation Tips: Part 2

When locating fans in a home, always pick rooms where people congregate, like the family room or a bedroom. Look for hot spots, like a sunroom or the kitchen. A fan makes it possible to adjust comfort in the trouble spots only, without cooling down the whole house. Don’t think of a fan as a chandelier and place it over the dining room table – this common error results in cold food and a fan rarely used, because it’s uncomfortable to have a wind blowing down on you while eating or doing your taxes.

I like to place fans over stairwells for circulation and in rooms with high ceilings. In homes with radiant heat sources, such as fireplaces or passive solar heating, a fan can push warm air into the rest of the structure, helping the system to work more efficiently.

Fans come in sizes from 24" to 60" in diameter. Generally, longer blades move more air, but blade pitch and design also affect performance. It’s generally better to oversize a fan than get one too small for the room. Fan manufacturers usually provide some guidance on correlating fan size with room area. As a rule of thumb, I like to size a fan to about one-quarter room use dimensions. By “room use,” I mean the area of a room that’s typically occupied. A 600-square-foot family-room may only require a 52" fan because the furniture arrangement centers on a 200-square-foot space. If the entire room were occupied, two 60" fans would work best.

When sizing large rooms with high ceilings, I like to use volume of air as a guideline. A 36" fan moves 2,500 to 4,000 cubic feet of air; a 48" fan moves 4,000 to 8,000 cubic feet. To simplify things, I round up the fan size 1' (36" fan becomes 4') and multiply by 1,000. Hence, a 36" fan moves about 4,000 cubic feet of air. A quick calculation of room volume tells you what size fan can best handle the area. Manufacturers often label their product’s actual cubic feet per minute capacity (ACFM) on the packaging, making it easy to do air volume calculations.

Ceiling height must always be a consideration when selecting and sizing a fan. Fan blades should hang at least 7' from the floor and not less than 18" from an adjacent wall or sloping ceiling. In many localities, municipal building codes enforce these clearances.

In rooms with high ceilings, I like to keep the blade height between 8' and 10' off the floor by using an extension pole. This height promotes the best airflow for both summer and winter applications. You can purchase extension poles in 6" increments, up to 8' in length. If the specific length required isn’t available, threaded conduit makes a good substitute.

Installing a Ceiling Fan

When wiring up a fan in a new home, the standard, code-compliant electrical supply for a light fixture works adequately. When using an existing service in an older home, make sure your ceiling box has a grounded electrical supply of 120 volts AC, 60 hertz, on a 15 ampere circuit. In either case, your ceiling outlet must be rated “for ceiling fan use” and attach to your framing firmly enough to support 50 pounds.

It’s always best to install electrical boxes before doing any wiring so that you can cut your cables to exact length. I like to start at the ceiling with a 4" octagonal metal box. Metal boxes install easily with a screw gun and cost less than the plastic boxes designed for ceiling fan use. In new construction, where the framing is exposed and readily accessible, I cut a length of 2" x 6" mounting block to fit snugly between ceiling joists, providing a stable support to attach my outlet. I find it easier to attach the mounting block by using a battery-powered screw gun rather than nails. A set of three 3" screws driven through each joist into either end of the block provides adequate support.

When setting your mounting block, remember to recess it far enough from the edge of your ceiling framing to allow for the depth of a junction-box and plaster ring. In a standard assembly, using a 2" deep box behind 1/2" drywall, the mounting block should be set 1 1/2" back from the edge of the joists. I attach my metal ceiling box to the backing block with two 1/2" long number 10 tapping screws.

Sometimes you have to set your ceiling box right under a joist. The standard 1 1/2" framing members don’t provide enough bearing for a safe and stable fan installation, so you’ll need to “sister” a 2" x 4" block along the length of the framing member where your fan will hang; then attach a 1" “shallow” box. This box won’t allow much room to tuck wires when you mount the fixture, but there’s always a little extra space in the canopy. Whether using a standard or shallow box, don’t forget to remove one of the 1/2" knockouts and attach a 3/8" romex connector to it before screwing the box in place. It’s a pain to do it later. I like to use metal connectors because you can loosen them easily and move a cable when needed. Once your cable’s locked in a plastic connector you’ve got to destroy the connector to move it.

In existing construction, you can install mounting blocking for your ceiling box by accessing the joists from an attic crawlspace or by cutting a 7" square hole through the ceiling cover. This size hole will allow you to wedge a block between the joists and squeeze in your screw gun to fasten it. Because you can’t get on either side of the joists, you’ll have to toenail the screws into the mounting block as shown in the illustration. Here a screw gun with a magnetic tip is indispensable, so you can hold the mounting block with one hand while fastening it with the other.

If you don’t want to patch the lid afterward, most lighting stores carry medallions from 8" to 26" in diameter that will conceal the opening, even if you’ve gone crazy with the sawzall. However, you can install a ceiling box without overcutting by using an expandable fan-mounting brace. This ingenious device works like a pressure-fit shower rod. Through a standard 4" cutout you insert the brace and lay it flat over the ceiling cover. Then, with a twist of your wrist, expand the brace to reach the joists on either side. A little added torque with an adjustable wrench buries glazing point-like spikes into the joists firmly. Attach your ceiling box to the brace with the hardware supplied.

After installing a standard single or double-gang switch box to the wall, you’re ready to run cable. If you’re going to operate the fan’s motor from its built-in pull-chain control, wire the fan like you would any light fixture. To work the motor and light separately from a wall switch, you will need to run an extra wire from wall to ceiling. Both armored and non-metallic cables come in three-phase wire versions, with ground, neutral, and two hots. I use 12-gauge, three-phase wire, none-metallic cable with a bare ground (12-3 NM w/ground). Red or red-and-black color coding indicates the second hot wire.

First, trim your wires at the switch box to 8" lengths and strip 1/2" of insulation off each wire. Next, splice together the ground that supplies the switch box with the ground from the ceiling box. If you’re using a metal box on the wall, clip a pigtail from this splice to the box, grounding it. Then splice together the common (white wires) from the switch box supply to the fixture run. Tuck the ground wire splice deep into a corner of the box and tuck the commons into another corner, getting these out of your way. Splice two pigtails to the hot (black wire) supply, then attach each pigtail to one of the switches. Finally, attach the black hot wire from the ceiling run to one switch and the red hot wire to the other. At the ceiling box you’ll be attaching the black wire to the motor’s black lead and the red wire to the light’s colored lead.

The wiring doesn’t change if you use a three-speed motor control switch, except that you’ll find the switch box a little more crowded. If you buy a single, integrated motor/light control, you can use a single-gang switch box and you won’t have to separate your hot supply. The switch comes with two brass terminal screws, one for each function.

When wiring in retrofits, hooking up your ceiling fan gets a little more complicated, not just because it’s harder to run cable through finished walls but because your power supply might be coming from the light fixture down to the switch instead of through the switch to the fixture. So don’t assume that an existing ceiling outlet doesn’t have power just because you turned off the switch. Before you get up on a ladder and start working, make sure the power’s off at the circuit breaker.

When replacing an existing ceiling light with a fan, I like to avoid the problems of running an extra hot wire by purchasing a fan with a remote control. Similar to a television remote, this control operates the fan’s built-in switches. The control mounts on a holster affixed next to the switch on the wall, or it can lay on your night stand. While convenient for a bedroom, the device requires batteries and it can be a pain to find in the dark. Some manufacturers make devices that operate your fan and light separately from a standard single-pole switch, without adding an extra wire. You control the fan functions by flipping the toggle once for the light, twice for the fan, and three times for both. Some high-end remotes attach at the switch box, require two wires only, and control all of the fan functions. These remotes don’t need batteries and won’t disappear under the couch; but these devices require a canopy and many don’t work on sloped ceiling applications. Most don’t work on flush-mount fans either, the type of fan you’ll need on most eight-foot ceilings.

If you’re stuck running a third wire to an existing ceiling box, or have to retrofit a new one, here’s a few wiring tips I learned from my electrician: First, determine the power source. In older homes your power may be supplied from the ceiling. If so, you’ll still use a three-wire cable, but one of the white wires will become a switch leg. For proper identification, mark both ends of this white wire with black electrical tape, indicating hot. Run power from the ceiling through this white wire to the wall, splice on two leads--one for each switch. Then connect the black and red wires to complete the motor and light circuits. Don’t forget to ground the switches, for safety.

When you’re ready to assemble and install your fan, open the box and read the instructions. There’s nothing amateurish about this simple step, which might save you time in the long run. Even my electrician, who has installed thousands of fans, takes a quick glance through the manufacturer’s instructions before putting up a style that he’s unfamiliar with.

The exact method of mounting your ceiling fan will depend on the make. But generally, fan manufacturers use two basic blueprints: the hanger-ball method, which accommodates sloped ceilings, and the hanger-pin and yoke method, used primarily for flat ceilings.

The hanger-ball method works with a nylon bushing attached to the end of a rod. This rod, which connects to the fan motor, hangs suspended from the bushing resting in a metal hanger like a swivel joint; allowing the fan to hang at any angle. Most fans employ this method of attachment.

With the ball-mount method, your fan will include either a metal mounting bracket called a “crossbar;” or a ceiling plate, which looks like a pancake box. Both of these fasten into your ceiling box, providing attachments for your fan canopy and a grounding screw. The first step in hanging your fan will be to secure either crossbar or plate to your ceiling outlet and a ground. This attachment should be snug, but not too tight, or the mounting hardware will bend.

Next, attach your fan’s extension pole to the fan motor following the manufacturer’s directions. If your fan has a one-piece canopy, insert the downrod through the canopy and feed the fan wires though the rod. Screw the rod to the fan housing. Make sure to tighten the lock-screw, so the rod assembly won’t unthread. Slide the nylon ball onto the downrod and insert the hanger-pin through the hole in the rod. Pull the hanger-ball up, aligning the slots over this pin. Don’t forget to tighten the set screw in the hanger-pin, or your fan will fall off the ceiling.

Tip: Make sure the detachable hatch or the open end of your mounting bracket faces up on a sloped ceiling, to provide your fan with full support.

To hang the fan, hold the fan body firmly. Depending on your hardware, you’ll either suspend the fan off a built-in hook at the ceiling plate, or insert the nylon ball at the end of your extension rod into the hanger bar. Next, connect the fan wires to the ceiling box wires; white-to-white, black-to-black, and green-to-green (ground). If your fan includes a light kit, tie the red wire to the light’s colored lead. When using an extension rod that’s over four feet long, you might need to lengthen fan wires by splicing additional leads. Make sure to align the hanger-pin with the slot on the nylon bushing or your fan will wobble and spin off the ceiling. Cap the wires snugly with wire nuts. Tuck the wires into the canopy and attach the canopy cover.

Tip: If your fan motor comes wrapped in plastic, keep this protective wrapping over the motor until you’ve finished handling it.

For fans with a hanger-pin and yoke system, first insert the hanger-pin and rubber bushing into the hanger bracket, then attach the hanger bracket to the ceiling box. The fan attaches to this bracket by means of a hook. So make sure your wires come into the ceiling box from above, or parallel with the bracket, to keep them from tangling on the hook.

Tip: Don’t forget to slip the canopy onto the pole before hanging the fan, or you’ll have to take the whole thing down and start over.

When attaching the blades, you first screw each blade down into its blade holder. Then, using your screwdriver to keep the blade-holder screw in place, position the flange of the holder against the fan flywheel and snug up the fasteners.

Tip: Attach the blades to the fan after mounting the motor to the ceiling, never before.

Fan blades come in balanced sets from the factory. That’s why you shouldn’t mix-match blades between fans. Sometimes a fan wobbles, but rarely will you have to balance a set of blades after installation. If your fan wobbles, check the hanger ball on your down rod to make sure it’s properly set into the hanger-pin. Then make sure all blades are secured firmly into their holders, and the holders secured tightly to the flywheel. Check to see if any blade irons have bent out of position. Do this by placing a yardstick vertically against the ceiling at the tip of a blade, then rotate the fan manually, seeing that every blade tracks at the same distance. If one doesn’t, bend the blade iron gently back into position.

On occasion, you will have to balance a set of blades. The process is like the dynamic balancing done on your car tires. Most fans come with a balancing kit, which includes balancing clips and adhesive lead weights. First, turn on your fan to accentuate the wobble. Then stop the fan, chose a blade at random, and place a balancing clip at the midpoint of this blade. Start the fan, see if it wobbles more or less. Stop the fan, move the clip to another blade then re-test. Check all the blades until you discover the blade on which the balancing clip makes the greatest improvement. Then, slide the clip inward and outward along this blade, testing the fan each time you move the clip, until you find the point of greatest improvement. Attach a permanent weight at this point.

With your blades in place, you’re ready to install the light kit. Remove the two screws on the switch housing at the bottom of the fan. Remove the plug at the center of the switch housing cap. (Tip: Clip the little bur left in the switch housing cap after you remove this plug, it’ll be in your way later.) Feed the light-kit’s lamp wires through the hole at the center of the housing cap. Screw the light to the cap; don’t forget to install the washer and lock nut. Connect the power supply to the leads designated “lights” in the switch housing: black to colored, white to white. Reinstall the cap, with light kit attached. Thread a light bulb into the socket and install the shade. On some multi-bulb light kits, you’ll feed wires through a lamp ring, and then attach the switch housing cap underneath the ring. Once you’ve finished, set the switches to off. Turn the power on at the breakers, flip the fan switches back on, test the fan and light, and then pat yourself on the back for a job well done.

For those of you wanting more information, you can read about how ceiling fans and lights kits are rated for energy conservation at the Building Technologies web site of the US Department of Energy, or check out the Ceiling Fans for Consumers section at the EPA’s Energy Star web site.