Why does an LED line show dots and how is it fixed?
Dots show when LEDs are widely spaced and the diffuser sits too close. Three things fix it: a strip density of at least 120 to 240 LEDs per metre, or a COB strip with hundreds per metre; a matt opal diffuser; and a profile 15 to 20 mm deep so the light mixes before leaving.
A rule from practice: the distance from LED to diffuser should be at least equal to the pitch between LEDs. A small 8 to 10 mm profile with a sparse strip gives a necklace. A mock-up on the table costs little next to rebuilding a plasterboard ceiling, so a sample of profile with strip is switched on in a dark room before ordering.
What is CRI and why does it matter for marble and wood?
CRI shows how faithfully a light source renders colours, on a scale up to 100. For an interior with stone and wood use CRI 90 or higher, better 95, and look at the R9 value (saturated red), which should exceed 50. Otherwise warm wood dulls and the pink vein of marble drifts to grey.
The test is simple: put a material sample under a light sample. A cheap CRI 80 LED turns cream marble greenish, while at CRI 95 the same marble looks as the designer intended. For a stone wall, herringbone parquet and slatted wood panels, as in our Urgel flat, colour rendering matters more than brightness.
Overall CRI is on the fitting's data sheet, but in practice ask for the manufacturer's measurement report.
Which colour temperature suits a home?
For living rooms it is usually 2700 to 3000 K, for the kitchen and work areas up to 3000 to 3500 K, and for the bathroom about 3000 K. A cold 4000 K white in a living room feels like an office, though it works well in a study or dressing room where accurate colour judgement matters.
Within one room all sources share one temperature, or profiles and spots give different tints on the walls and it shows. If you want to change the mood, choose dim-to-warm solutions, where lowering brightness warms the light from 3000 to 2000 K, like an incandescent bulb. It works in the evening and adds cosiness without separate scenes.
General principles of scenes are in our article on interior lighting.
Where do the drivers hide and how is power routed?
Drivers go somewhere accessible: a technical cupboard, under a hatch in the corridor ceiling or a niche behind furniture. They are not buried in blind voids: a driver lasts 7 to 10 years, and replacing it through tile or plasterboard wrecks the renovation.
On 24 V strips a run of no more than 5 m is fed from one side; over that length, voltage drop creates a step in brightness at the end of the line and power is fed from both ends. Cables from driver to profile run in protective conduit with slack, and the design notes which driver feeds which line. Then in five years the electrician finds the right one in a minute.
Dimmable drivers are chosen to suit the control system: DALI, phase or 0-10 V, and we cover it in the article on lighting control.
Why does a luminaire flicker and how is it avoided?
Flicker appears when a cheap driver or an incompatible dimmer modulates the current. The eye may not see it, but the head tires, and bands show on a phone camera. A quality constant-current driver, a compatible dimmer and a good strip avoid it.
Before buying, driver, dimmer and luminaire are checked as a set: the driver maker publishes a list of compatible dimmers. A simple site test: switch the light to 10 to 30 percent and film the screen in slow motion. If flickering bands show, the set is changed before plastering.
This is one of the points where saving on equipment comes back as complaints every evening, and redoing it costs more than the whole lighting design.
Is a magnetic track a lasting solution?
It is, if you choose a system from a major manufacturer and buy a batch of spare modules. A 48 V extra-low-voltage magnetic track is recessed flush into the ceiling and lets you swap spotlights, linear modules and pendants without opening the ceiling.
Advantages: flexibility when furniture moves and light is turned to a new picture. Drawbacks: modules from different makers are incompatible, the track shows if badly fitted and the profile costs more than a recessed line. A serious question for the future: the maker must still produce modules in ten years, so choose known brands and buy spare parts with the system.
For an art zone a track is often best, while a bedroom needs only a couple of profiles and a night mode. We wrote about lighting artworks in the article on art in the interior.
How can BCN YARD help with architectural lighting?
We visit the site, measure heights and agree the scenes with you, then test samples of profiles and strip in the actual room before ordering. Drivers and routes are planned with the other services. We work with our own crew and trusted subcontractors, one person is responsible for the site, and we speak Russian and Spanish. The estimate is prepared after the visit.
Frequently asked questions
Why does an LED line show dots?
LEDs are too far apart or the diffuser sits too close. Use a strip of 120 to 240 LEDs per metre or COB, an opal diffuser and a profile 15 to 20 mm deep. The distance from LED to diffuser should be at least the LED pitch, and the sample is lit in a dark room before ordering.
What is CRI and why does it matter for marble?
CRI measures colour fidelity on a scale up to 100. Stone and wood need CRI 90 or higher, better 95, and R9 above 50. At CRI 80 cream marble turns greenish and the warm vein dulls. The data sheet gives CRI and for important jobs the manufacturer's measurement report is requested.
Where do the drivers of LED profiles hide?
Somewhere accessible: a technical cupboard, a hatch in the corridor ceiling or a niche behind furniture. A driver lasts 7 to 10 years, and replacing it through tile or plasterboard wrecks the renovation. On 24 V no more than 5 m of strip is fed from one side, and the design notes what feeds what.
Is a magnetic track a lasting choice?
Yes, if you choose a system from a major manufacturer and buy spare modules. A 48 V track is recessed into the ceiling and modules move without opening it. Modules from different brands are incompatible, so it matters that the maker still produces parts in ten years.