Installing an LED strip in a room for ambient lighting

An LED strip turns an ordinary room into a warm space, with precise, directional and very economical ambient lighting. It sticks anywhere: under a kitchen cabinet, along a skirting board, behind a screen or under a shelf. This guide is for those who want to equip a room without embarking on major electrical work: the connection is limited to a socket and a transformer.

Choosing your LED strip: intensity and colour temperature

Intensity is expressed in lumens: allow about 300 to 500 lumens per metre for ambient lighting under a cabinet, and up to 1,000 lm/m for task lighting. The colour temperature is chosen in kelvins: 2,700 to 3,000 K gives a warm, soft light, ideal in the living room or bedroom; 4,000 K, neutral, suits the kitchen; 6,500 K, cool, is reserved for work areas. For a stuck-down strip, prefer the 60 LEDs per metre model in 12 V or 24 V, which offers a uniform finish without visible bright spots.

  1. Measure the exact length to light with a tape measure and cut the strip only at the cut marks, usually every 5 cm at the copper pads, never anywhere else.
  2. Degrease the support with a cloth soaked in methylated spirits, let it dry, then peel off the protective film from the adhesive.
  3. Stick the strip progressively pressing firmly without pulling on it, turning cleanly in the corners with 90° connectors.
  4. Connect the connector to the strip respecting the polarities (+ and -) and link it to the 12 V or 24 V power supply suited to the total wattage.
  5. Plug the transformer into an earthed socket, then test each section by switching the light on.
Tip: Calculate the power of the power supply: multiply the strip's wattage per metre (often 9 to 15 W/m) by the installed length, then add a 20% margin. A 5 m strip at 14 W/m thus requires a transformer of at least 84 W; an undersized power supply heats up, flickers and fails quickly.

Where to stick the strip for a successful result

Under a skirting board, the strip creates an elegant grazing light; under kitchen cabinets, it lights the worktop without shadows; at the ceiling behind a coving, it diffuses indirect light that visually enlarges the room. The golden rule: the strip is always placed where you cannot see the LEDs directly, for a soft, glare-free effect. Also think of letting the strip run continuously: do not cut it too short to save a few centimetres.

Adding a dimmer or a connected strip

If you want to adjust the intensity, place a compatible dimmer between the transformer and the strip: not all models support it, check the mention on the packaging. Connected strips are controlled from your phone via a Wi-Fi or Bluetooth bridge, with timers and colour scenes. Whichever option, keep the transformer accessible so it can be replaced easily.

Precautions and mistakes to avoid

In one hour, your room gains a modular and very economical ambient lighting: one metre of LED strip consumes about 14 W, like a low-energy bulb. Choose your colour temperature according to the use, measure twice before cutting, and everything goes smoothly. All that remains is to enjoy the effect.

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