Layout spacing, IC vs non-IC housings, trim types, and wiring in series
Recessed lighting (also called can lights, downlights, or pot lights) are light fixtures installed into hollow openings in the ceiling, creating a streamlined look with light that appears to come from the ceiling itself.
A recessed light consists of three main components: the housing (can) installed above the ceiling, the trim visible from below, and the bulb or integrated LED light source. Modern installations increasingly use integrated LED housings that eliminate bulb replacement.
Proper spacing ensures even illumination without dark spots or excessive overlap. The key formula is based on ceiling height.
Formula: Maximum spacing between lights = Ceiling height ÷ 2
This ensures overlapping light cones prevent dark spots. You can space lights closer for more illumination, but not farther apart.
| Ceiling Height | Maximum Spacing Between Lights | Wall Distance (Half Spacing) |
|---|---|---|
| 8 feet | 4 feet | 2 feet |
| 9 feet | 4.5 feet | 2.25 feet |
| 10 feet | 5 feet | 2.5 feet |
| 12 feet | 6 feet | 3 feet |
Use standard spacing formula. 5-6" housings work well for most 8-10 foot ceilings.
Space 18-24 inches from wall, 24-30 inches apart over work areas. Use bright 3000K+ bulbs.
Position 12-18 inches from wall, use adjustable gimbal trims to aim at focal points.
Two lights flanking mirror 24-30 inches apart, or single centered light above mirror.
IC stands for "Insulation Contact." IC-rated housings can be in direct contact with insulation, while non-IC housings require 3 inches of clearance from insulation.
| Type | Insulation Contact | Heat Characteristics | Best Use |
|---|---|---|---|
| IC-Rated | Can touch insulation | Thermal protection prevents overheating | Insulated ceilings, energy-efficient homes |
| Non-IC Rated | Requires 3" clearance | Runs hotter, needs airflow for cooling | Uninsulated areas, under unheated attics |
| Trim Type | Appearance | Light Output | Best Use |
|---|---|---|---|
| Baffle Trim | Ribbed interior, white or black finish | Soft, reduces glare | Living rooms, bedrooms, general lighting |
| Reflector/Specular Trim | Smooth, mirror-like finish | Maximum brightness | Kitchens, task areas, commercial spaces |
| Gimbal/Eyeball Trim | Adjustable directional socket | Focused, aimable | Accent lighting, artwork, architectural features |
| Shower/Wet Location Trim | Glass lens with gasket seal | Moderate, diffused | Showers, saunas, outdoor soffits |
| Wall Wash Trim | Scoop or shield on one side | Directional toward wall | Highlighting walls, artwork, even wall illumination |
| Pinhole/Adjustable Aperture | Small opening, discreet | Narrow beam | Minimalist design, focused accent lighting |
LED technology offers significant energy savings and longevity compared to traditional incandescent and CFL bulbs. There are several approaches to LED lighting in recessed cans.
Recommendation: Use consistent color temperature throughout connected spaces. Mix 2700-3000K for living areas, 3500K for kitchens/baths.
Airtight (AT) rated recessed lights prevent air leakage between living spaces and unconditioned attics, improving energy efficiency and preventing moisture problems.
Look for these features on airtight-rated recessed lights:
Daisy-chaining means wiring multiple recessed lights in series from a single switch, where each light connects to the next in a chain. This is the most common wiring method for recessed lighting.
For larger rooms, divide lights into multiple zones controlled by separate switches:
| Bulb Type | Wattage Each | Max Lights (15A Circuit) |
|---|---|---|
| LED (integrated) | 10-15W | 100+ lights |
| LED bulb | 12-18W | 50-80 lights |
| CFL | 23W | 30-40 lights |
| Incandescent | 65W | 12-15 lights |
Circuit capacity = 15A × 120V × 80% (NEC derating) = 1,440W maximum continuous load
Not all LED lights are dimmable. Always verify compatibility:
Calculate spacing using ceiling height formula. Mark center points on ceiling. Use stud finder to verify no joists or obstructions at marked locations.
Shut off power at breaker panel to switch location. Verify power is off with voltage tester at switch box before proceeding.
Cut first hole using template or hole saw. Fish 14/2 Romex from switch box to first light location through attic or ceiling cavity.
Cut all remaining holes for recessed lights. Ensure clean cuts for proper clip engagement and professional appearance.
Fish 14/2 cables from first light to second, second to third, etc. Label cables at each location (incoming vs outgoing) to simplify connections.
Secure incoming cable with cable clamp. Connect black to black, white to white, ground to ground using wire nuts. If daisy-chaining, include outgoing cable in connections.
Push housing into hole from below. Deploy spring clips by pressing tabs upward until clips snap into place above ceiling. Housing should pull tight against drywall.
Wire and install each housing in sequence. For intermediate lights, connect incoming and outgoing cables together with light wires using 3-way wire nut connections.
Connect hot wire to switch terminal, neutral to neutral bundle in box, ground to switch ground screw. Restore power at breaker and test switch operation.
Install appropriate trim rings by squeezing springs and inserting into housing slots. Install LED bulbs or modules. Test all lights for proper operation.
Note: Recessed lighting installation involves electrical work that must comply with NEC and local building codes. Permits may be required. Consider hiring a licensed electrician if you're not experienced with electrical installations or running cable through ceilings.
Disclaimer: This guide provides general information about recessed lighting installation. Local building codes and manufacturer specifications may require different approaches. Electrical work can be dangerous and may require licensed professionals. Always follow manufacturer instructions, obtain required permits, and consider hiring a licensed electrician for complex installations.