1. [Home](/) 2. [Guides](/guides/) 3. [Lighting, outlets and everyday electrical problems](/guides/home-lighting-guide/) 4. Recessed lighting basics # Recessed lighting basics Recessed lights give clean, even light, but they depend on good layout, the right housing for what is above the ceiling, and a dimmer that suits the LEDs. ## Key takeaways - Plan the layout around the tasks and the room, not a uniform grid, and check what is above the ceiling before you mark positions. - Use IC-rated housings wherever insulation touches or sits near the fixture, and ask about airtight ratings in Ohio's cold winters. - Pick one color temperature per room, with warm white around 2700K to 3000K for living spaces. - Pair LED trims with an LED-rated dimmer, and leave ceiling and wiring work to an electrician. ## Planning the layout Good recessed lighting starts with a plan on paper. A common rule of thumb for general lighting is to space fixtures about half the ceiling height apart, so roughly four feet on an eight-foot ceiling. Treat it as a starting point and adjust to the room. Think about what happens in the room. In a kitchen, place lights so they fall on the counter in front of you, not behind you where your body casts a shadow. Over an island, a pair of lights in line often works better than a spread of cans. In hallways, a single row is usually enough. In living rooms and bedrooms, avoid placing lights directly over a bed or in the glare line of a TV. Lights placed about two feet from a wall will light the wall surface. Lights placed closer graze the wall and show texture, which looks best on brick or stone and less good on uneven drywall. The ceiling decides what is possible. Joists, ducts, plumbing vents and existing wiring limit where a can can go, and in older houses what is above the ceiling may not match what you expect. A grid of many cans can feel flat and harsh, so mix them with lamps, under-cabinet lights or pendants. See [lighting](/services/lighting/) for design and installation help. ## IC-rated and airtight housings The housing is the part inside the ceiling, and it matters more than the trim you see. IC stands for insulation contact. An IC-rated housing is built to sit against insulation without overheating. A non-IC housing needs clearance around it, commonly three inches, which means insulation must be kept away from it. That is hard to do and is often done wrong in a finished attic. Check the label inside the housing. If a ceiling has insulation above it, use IC-rated housings. For an existing non-IC can you cannot easily reach, an electrician can tell you whether it can be replaced or whether a different approach is safer. Airtightness matters in this climate. Southwest Ohio has cold winters and humid summers, and an unsealed can in a ceiling below an attic lets warm, moist indoor air move into the attic. In winter that can contribute to frost and condensation on the roof framing and can add to heat loss. Look for housings that are labeled airtight and sealed to the drywall. Some locations need specific ratings. Fixtures in or near showers need to be rated for wet or damp locations, and covered porches need fixtures rated for them. Ceilings that separate floors, or the garage from living space, can have fire-rating requirements, so check with your local building department. ## Color temperature and trims Color temperature is measured in Kelvin. Around 2700K is warm and close to an old incandescent bulb, 3000K is a slightly crisper warm white, 3500K to 4000K is neutral, and 5000K and above looks bluish. For living rooms, bedrooms and dining rooms, 2700K to 3000K is the usual choice. Kitchens and work areas sometimes use a little cooler light, but pick one temperature for a room and keep it, ideally across an open floor plan, so that adjacent lights do not look mismatched. Also look at color rendering, shown as CRI. A higher number, 90 or above, shows food, skin and paint colors more truthfully, which helps in kitchens and bathrooms. The trim sets the look and the light spread. Baffle trims reduce glare and suit most rooms. Reflector trims give more output. Gimbal or adjustable trims aim light at a wall or artwork and are useful on sloped or vaulted ceilings, where a standard can would point at an angle. Thin LED wafer lights, which connect through a small junction box, fit where there is little space above the ceiling, but check the label for IC and airtight ratings like any other housing. Do not buy by wattage. Compare lumens for brightness and use a dimmer to adjust. ## Dimmers and LED compatibility Recessed lights are often the main light in a room, so a dimmer is worth having. Most modern recessed fixtures use integrated LEDs or LED trims, and they need a dimmer rated for LED. An older dimmer made for incandescent bulbs may cause flicker, buzzing, a limited dimming range, or lights that turn off at the lowest setting. Check the dimmer's minimum and maximum load against the total wattage of the lights on it. A few low-wattage LEDs on a large dimmer can fall under the minimum and flicker. Manufacturers often publish lists of compatible dimmers and fixtures, and it is worth checking before you buy a set of trims. Use the same fixture model throughout a dimmed zone so they all respond the same way. Think about zones. Putting a whole kitchen on one dimmer limits flexibility. Separate dimmers for the work area, the island and the dining area let you adjust each one. Some smart dimmers need a neutral wire in the switch box, which older homes often lack. An electrician can check the box and suggest a dimmer that works with your wiring. If lights already flicker, the cause may be elsewhere, as described in [why your lights flicker](/guides/home-lighting-guide/flickering-lights/). ## What an electrician should handle Installing recessed lights is more than cutting holes. The work involves finding joists, ducts and cables before cutting, running new wiring through finished ceilings, connecting to a circuit that can carry the added load, and sealing and insulating around each housing correctly. Mistakes show up later as heat damage, air leaks or lights that do not work reliably. On older homes the unknowns multiply. The wiring in the ceiling may be old cloth-covered cable, may be spliced in places you cannot see, or may be on a circuit that already serves too much. Aluminum wiring or knob-and-tube wiring needs special handling and should be evaluated first. Permits may be required for new circuits or fixtures, and your local building department can tell you what applies. You can safely choose the layout, colors and trims, then have an electrician confirm the plan, check the circuit and install the housings. Replacing LED trims in good existing cans, with the power off, is a smaller job, but if you find old, damaged or non-IC housings, stop and ask. For help, see [lighting](/services/lighting/) or [contact us](/contact/). The broader overview is in the [home lighting guide](/guides/home-lighting-guide/). ## Frequently asked questions How many recessed lights do I need in a room? It depends on ceiling height, the room's use and how bright you want it. A common starting point is spacing about half the ceiling height apart, then adjusting for tasks such as counters and reading areas. An electrician can sketch a layout around your joists and wiring. Can insulation touch recessed lights? Only if the housing is IC-rated. Non-IC housings need clearance from insulation because they can overheat. Check the label inside the housing, and ask an electrician if you cannot find one. Can I put LED bulbs or trims in my old recessed cans? Often yes, if the existing housing is in good condition and the LED product is made to fit it. Turn off the power first, and if you find damaged wiring, a non-IC can under insulation or signs of heat, stop and have an electrician take a look. 5 min read. ### Want us to handle it? Radin Electric works in Hamilton, Fairfield, Oxford. [Get a quote](/contact/)[Call 513-827-4498](tel:+15138274498) ### More in this guide - [Lighting, outlets and everyday electrical problems](/guides/home-lighting-guide/) - [Why your lights flicker](/guides/home-lighting-guide/flickering-lights/) ### Related services - [Electrical Repair & Troubleshooting](/services/electrical-repair/) - [Lighting & Ceiling Fans](/services/lighting/) ### Service areas - [Hamilton](/areas/hamilton/) - [Fairfield](/areas/fairfield/) - [Oxford](/areas/oxford/) ### Other guides - [Electrical panels and older home wiring](/guides/electrical-panel-guide/) - [EV chargers and backup generators at home](/guides/ev-and-generators-guide/) ## Call 513-827-4498 or send a quote request and we will talk through your project. [Get a quote](/contact/) [Call 513-827-4498](tel:+15138274498) --- **Radin Electric** · 1329 Pater Ave, Hamilton, OH 45011 · 513-827-4498 · radinelectric@yahoo.com [Get a quote](/contact/) · [Services](/services/) · [Guides](/guides/) · [FAQ](/faq/)