Under-Cabinet and Recessed Lighting: LED Types, Colour Temperature and CRI

Under-cabinet lights and recessed lights do most of the work in a kitchen, and both are bought from spec sheets full of terms that are easy to skim past. This page explains the product types and the terms, so you can tell a good fixture from a poor one. Where to place the lights is covered on the kitchen lighting overview, and island fixtures on pendant and island lighting.

Under-cabinet lighting types compared

What separates good LED tape from poor tape

• LED density. More LEDs per foot gives a smoother line of light. Sparse tape shows as dots.
• Color consistency. Good manufacturers sort their LEDs tightly, so one reel matches the next. Buy all the tape for a kitchen at once.
• A channel. An aluminum channel holds the tape straight, carries heat away and takes a diffuser lens. Tape stuck directly to the cabinet bottom tends to sag and fail early.
• The right voltage and driver. The driver has to match the tape's voltage and be sized for the total length, with margin. Long runs lose brightness toward the far end unless they are fed correctly, which the installer plans for.

Direct-wire versus plug-in

In a remodel with open walls, direct-wire is the right choice, and it is new wiring that needs a permit. The cable has to come out of the wall at the right height behind the cabinets and before the backsplash is tiled, so it is coordinated with the cabinet plan. See electrical permits for kitchen remodels.

With low-voltage tape, decide where the driver lives. It needs to be accessible for service and have some air around it. Common places are inside an upper cabinet, above the cabinets, or in the sink base. A driver buried in a wall cannot be replaced without opening the wall.

Diffusers and the dotting problem

A polished countertop acts as a mirror for whatever is under the cabinet. Bare LED tape reflects in polished quartz or granite as a row of bright dots, and once seen it is hard to ignore. Three things fix it:

• A frosted diffuser lens over the tape, in a channel deep enough that the dots blend before the light reaches the lens. A shallow channel with a clear lens does little.
• High-density or continuous tape, where the LEDs sit so close together, or under a continuous phosphor coating, that they read as a line.
• Position. Mounting the light toward the front of the cabinet, aimed slightly back, moves the reflection out of the usual line of sight and lights the counter more than the wall.

Honed and leathered countertops reflect far less, so the choice of counter finish affects how much diffusion you need. See countertop finishes, edge profiles and thickness. A light rail along the bottom front edge of the upper cabinets hides the fixture from a seated eye line. Flat-bottomed frameless cabinets may need a routed channel instead, specified with the cabinet order.

Color temperature explained

The U.S. Department of Energy defines correlated color temperature (CCT) as a specification of the color appearance of the light emitted by a lamp, measured in kelvin (K). Its purchasing guidance lists typical values of 2,700 K (warm), 3,000 K (soft), 3,500 K (neutral) and 4,100 K (cool):

Lower numbers look warmer and yellower, and higher numbers look cooler and bluer. Most kitchens are comfortable at the warm to soft end. The choice interacts with your finishes: warm light flatters wood and cream and can make a cool white cabinet look yellow, while cooler light keeps whites crisp and can make warm wood look flat. Look at your cabinet and counter samples under the actual fixture before ordering. How light changes paint and cabinet color is covered in choosing kitchen colors for Pacific Northwest light.

Color rendering index (CRI) explained

Color rendering describes how accurately a light shows the colors of the things it falls on. Two fixtures with the same color temperature can make the same tomato look vivid or dull.

The color rendering index is the common measure. The Department of Energy describes it as a measure of light quality, with a higher value indicating a better light source. Its guidance on LEDs says a minimum CRI of 80 is recommended for interior lighting, and that a CRI of 90 or higher indicates excellent color fidelity. It also cautions that CRI is far from a perfect metric and is weak at predicting saturated reds, which is why a second figure, R9, is often quoted.

For a kitchen, where you judge whether food is cooked and where wood, stone and paint were chosen with care, fixtures of 90 or higher are worth asking for, particularly under the cabinets and over the island.

Recessed lights: housings, trims and beam spread

Housing types

• New-construction housings fasten to the joists while the ceiling is open. This is the normal choice in a gut remodel.
• Remodel housings go in through a hole cut in an existing ceiling and clip to the drywall.
• Canless (wafer) lights have no housing, only a slim fixture and a small junction box. They fit where framing or ducts leave no depth.

Where a recessed fixture sits in an insulated ceiling, such as under an attic, it needs to be rated for contact with insulation and to limit air leakage. The fixture's label states both. Your electrician selects for this, and the energy code points are on the main lighting page.

Trim types

Beam spread and size

Beam spread is the angle of the cone of light. A wide (flood) beam overlaps with its neighbors for general light. A narrower beam puts a stronger pool on a specific surface, which is useful over a sink or island from a high ceiling. The higher the ceiling, the narrower the beam needed to deliver the same light to the counter.

ENERGY STAR on recessed lights

The ENERGY STAR label is still available on downlights. Its current key criteria call for an efficacy of at least 82 lumens per watt, a color rendering index (Ra) of 80 or higher with an R9 above 0, and, for products sold as dimmable, continuous dimming from full output down to at least 20 percent. Treat the label as a floor: it means a CRI of at least 80, and you can ask for 90.

Dimmer compatibility

LEDs dim differently from the bulbs older dimmers were built for, and a mismatch shows as flicker, buzzing, a narrow dimming range or lights that glow when off.

• Match the method. Fixtures and drivers are designed for a particular dimming method, and the dimmer has to use the same one. The fixture's spec sheet states it.
• Use the compatibility list. Fixture and dimmer manufacturers publish lists of tested pairings. Choosing from the list is the reliable route.
• Test one first. Install one fixture and its dimmer, and check the full range before the rest go in.

Put under-cabinet lights and recessed lights on separate dimmers. What the code requires of the wiring is on the kitchen electrical code page.

What to check before you buy

1. Color temperature, the same for every fixture in the room.
2. CRI of 90 or higher where you can get it, and the R9 value if stated.
3. Under-cabinet: tape density, a channel with a frosted diffuser, and where the driver will go.
4. Recessed: housing type for your ceiling, insulation-contact and airtight ratings where needed, trim type and beam spread.
5. Dimming method, and a dimmer from the fixture's compatibility list.

Who should choose which

• A full remodel with polished counters: hardwired high-density tape in a deep channel with a frosted lens.
• A standard flat ceiling with open framing: new-construction housings with baffle or regressed trims.
• A ceiling crowded with ducts and joists: canless lights, choosing a regressed style over a flat lens if depth allows.

JDI's published planning range for a full lighting redesign as a kitchen add-on is $2,000-$6,000 before sales tax. It is a planning range, not a quote. JDI Construction draws the lighting with the cabinet plan and settles fixtures, drivers and dimmers before rough-in. To plan yours, start at kitchen remodeling in Vancouver.