How Many Can Recessed Light Fixtures Should Be Used Together?

How Many Can Recessed Light Fixtures Should Be Used Together?

Recessed lighting canisters provide attractive ambient lighting, but because the fixtures are hidden behind the ceiling, you need more than one to adequate illuminate a room. The optimum number of fixtures for a particular space depends on a number of factors, including bulb wattage, canister width, and room shape and dimensions. The number of lights you can put on a circuit is limited by the breaker rating, but in most cases, that isn’t an issue.

Fixture Spacing

The ideal spacing of recessed lighting fixtures results in each part of the floor having approximately equal illumination. Each fixture provides a cone of light, and the cones should overlap. The fixture spacing necessary to produce this effect depends on several factors, including bulb intensity, diameter of the fixture opening and height of the ceiling. As a rule of thumb, you can usually divide the height of the ceiling by 2 and space the fixtures by this amount. The optimum spacing between standard fixtures in a room with an 8-foot ceiling is therefore 4 feet.

Omnidirectional and Directional Fixtures

Overusing recessed lighting, or using it improperly, can produce undesirable effects. Lining the fixtures up in a row creates a sightline pattern that creates a less-than-inviting airline runway effect — it’s often better to space fixtures in slightly irregular patterns. Moreover, spacing standard fixtures too closely can provide too much illumination, giving the impression of a commercial showroom. Some fixtures are directional, though, and you often need to space them closer together than omnidirectional ones to produce the desired lighting effect, which may include patterns of indirect lighting on the walls or ceiling.

Breaker Limitations

The main limitation to the number of recessed fixtures you can run at the same time is the rating of the circuit breaker that controls the circuit. Each fixture with a 60-watt incandescent or halogen bulb draws about 1/2 amp, so a 15-amp breaker for a standard lighting circuit would be able to handle 30 of them. That’s more than you’d ever install in most rooms. Each CFL or LED bulb typically gives the same amount of light as a 60-watt incandescent bulb while drawing 10 watts or less, which is equivalent to a current draw of 1/12 amp. Thus a 15-amp circuit can safely control 180 or more fixtures that use CFL or LED bulbs.

Installation Tips

Installing recessed lighting is less problematic if you have access to the attic. In that case, it’s a simple matter to anchor them to the ceiling joists and pull the wires to connect them. When you don’t have access, you need to use fixtures designed to be attached to the ceiling drywall. These often don’t provide as much lighting as ones that attach to joists, and you may need more of them. If your ceiling is insulated, be sure to use IC fixtures, which are rated for insulation contact. Failure to do this creates a fire hazard.

Writer Bio

Chris Deziel has a bachelor’s degree in physics and a master’s degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. As a landscape builder, he helped establish two gardening companies.