Indoor vs outdoor LED in Nepal: brightness, IP rating and the monsoon

Brightness: the number that decides everything outdoors

Brightness is measured in nits (candela per square metre). An indoor display typically runs 600 to 1,500 nits. An outdoor display facing daylight needs 5,000 to 10,000.

That gap is not a refinement, it is a threshold. Put a 1,000-nit screen outdoors and it does not look slightly dim — it becomes a milky grey rectangle, genuinely unreadable, for the entire part of the day when the sun is on it. Which is, inconveniently, the part of the day with the most traffic past it.

For Nepal specifically, 6,000 nits is a sensible working minimum for any screen facing open daylight, with 8,000 to 10,000 giving real headroom for direct sun on the screen face and for west-facing sites in the afternoon. Kathmandu sits at altitude with strong, clear light for much of the year, which is not a forgiving environment for an underspecified display.

Why indoor screens run dim on purpose

It is worth understanding that indoor brightness is low by design, not by limitation. A 5,000-nit wall in a boardroom would be genuinely unpleasant to sit in front of, and in a control room it would defeat the point entirely — operators work in dim rooms precisely so they can read the screens comfortably for hours.

Nepal's first COB control-room installation was specified at 600 nits for exactly this reason. The engineering question there was not how bright it could be but whether it held its grayscale accurately at low output, which is a much harder thing to deliver.

IP rating, and the detail most quotes leave out

IP65 means dust-tight and protected against water jets from any direction. For outdoor LED in Nepal it is the baseline, not an upgrade.

The detail that matters, and that is frequently glossed over: ask whether the rating applies to the front face only, or to front and rear. Front-only ratings are common and considerably cheaper, and they are not adequate here. Monsoon rain does not fall politely onto the front of a screen — it is driven sideways by wind and thrown upward off the road surface, and it reaches the back of a cabinet as readily as the front.

What actually fails in a poorly sealed outdoor display is almost never the LEDs. It is corrosion at the connectors behind them, which starts quietly, is invisible until it isn't, and typically shows up as intermittent faults a season or two after installation.

Dust, and why it is a year-round problem

Nepal's dry season brings sustained airborne dust, particularly in the Kathmandu valley. Dust ingress into a cabinet insulates components that were designed to shed heat, and heat is the primary driver of LED degradation. A display running hotter than designed simply ages faster.

This is one of the practical reasons COB performs well in dusty environments even indoors: with the diodes sealed under resin, there is no package geometry for dust to settle into on the display face itself.

Running cost, which is an outdoor problem specifically

A large outdoor screen at full brightness around the clock draws real power, and at Nepali tariffs that becomes a significant operating line rather than a rounding error. Outdoor sites are routinely modelled on expected media revenue with no realistic figure for electricity, and the economics only become visible a year in.

Two settings do most of the work. An ambient light sensor continuously matches output to conditions, so the screen is bright at midday and considerably dimmer at night — which protects both the bill and your relationship with everyone living opposite it. Scheduled on/off shuts the screen down in hours when nobody is watching. Both should be configured at commissioning rather than left at defaults.

It is also worth knowing that real-world consumption sits well below the peak rating, because peak assumes a full-white screen and real content is mostly mid-tones. A public information display running sixteen hours a day, as at Tokha Municipality Ward 5, draws far less than its nameplate figure suggests.

Semi-outdoor: the case that catches people out

Covered forecourts, deep shop awnings, stadium concourses and window displays behind glass are neither fully indoor nor fully outdoor, and they are where specifications go wrong most often.

The test is not whether rain reaches the screen — it is how much light does. A display behind south-facing glass is, optically, an outdoor screen and needs outdoor brightness, even though it will never get wet. Conversely, a screen under a deep permanent canopy may need outdoor sealing for the humidity while running at moderate brightness. Judge the two requirements separately.

Common questions

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