Designed for +45 °C: calculated for the Uzbek climate

A luminaire designed for a European climate operates under different conditions in Uzbekistan. Three numbers explain what exactly changes.

Heat: +44.3 °C outside and what happens inside the housing

On 19 July 2026 Tashkent recorded +44.3 °C. For a luminaire that is not weather but an operating mode: inside a sealed housing, in the sun and under the ceiling of a production hall the temperature runs higher than outdoors, and LED degradation and driver life are counted from temperature, not from the calendar.

Two consequences follow. First, the housing has to be a heat sink. In our series it is an extruded aluminium profile, so heat is removed by geometry rather than by a fan that nobody in a production hall is going to service. Second, the driver operating range has to be asked for as a number and written into the data sheet. Ours states a range from -30 to +50 °C.

What to check with any supplier: whether the operating range is declared for the assembled luminaire rather than for a bare module, and whether the temperature at which luminous flux was measured is stated. Flux at Ta = 25 °C and flux at Ta = 45 °C are different numbers for the same product.

On that question we have half an answer so far: the operating range in our data sheet is stated for the assembled luminaire, while the temperature at which flux was measured will arrive with the LM-79 report we have yet to receive.

Dust: 1,585 µg/m³ and what a storm does to light

During the storm in May 2025 the PM10 concentration reached 1,585 µg/m³. Dust does not merely settle on the diffuser and eat into the flux. It clogs gaps, gets inside a housing that is not sealed and settles on the board, degrading heat removal, which takes us back to the first section.

The practical conclusion: streets, plant grounds and fuel stations take IP65; a production hall and a warehouse are fine with IP54, but even there it is worth asking for the maintenance schedule. Smooth glass wipes clean, while a textured diffuser collects dust in its grooves and loses output with every wash.

The grid: a 14.2 GW peak and the capacity you free up

On 20 July 2026 consumption in the power system peaked at 14.2 GW. For a business that is not an abstraction: there is physically no spare capacity at the substation, and expanding it costs more than replacing the lighting.

This is why our replacement calculations always show the freed capacity in kilowatts as a separate line. It is often that figure, rather than the savings in UZS, that turns out to be the main argument: after the lighting is replaced there is capacity for a new machine or for air conditioning, and it does not have to be bought from the grid.

What follows for the specification

Three lines worth adding to a specification for a site in Uzbekistan:

• the operating temperature range of the assembled luminaire and the temperature at which luminous flux was measured;
• the IP rating for the actual installation location, not “the highest available”;
• the maintenance schedule and repairability: the driver and the module should be replaceable on site, without shipping the luminaire back to the maker.

None of these lines makes the lot more expensive. Each of them screens out a supplier who designed the luminaire for a different climate.