Lighting car parks: linear luminaires, sensors and standards

Which lux levels apply in a car park

Car park lighting falls under EN 12464-1, the standard for lighting of indoor workplaces. The standard sets an average illuminance on the floor for each zone:

• Entrance and exit ramps by day: 300 lux, so that eyes coming in from outside can adapt.
• Entrance and exit ramps at night: 75 lux.
• Traffic lanes: 75 lux, UGR no more than 25.
• Parking bays: 75 lux.
• Ticket office and pay station: 300 lux.

Alongside the average, uniformity counts: the lowest value must be at least 0.4 times the average. A dark corner behind a column is therefore just as much a reason for rejection as a low average. For colour rendering the standard asks for at least Ra 40; most LED luminaires achieve Ra 80 or higher. NEN 2443, the Dutch design standard for car parks, may add requirements in the specification; check this before you start drawing. Emergency lighting falls under EN 1838 with at least 1 lux on the escape route and belongs in the same lighting plan.

IP65, impact resistance and cold: what the luminaire must withstand

Cars bring in rain, road salt and brine, the space is unheated and an open-sided car park has the wind blowing through it. So choose a dust-tight luminaire that withstands water jets: IP65 is the minimum. If the floor is cleaned with a pressure washer, as at a car wash, choose IP69K.

A polycarbonate diffuser with stainless steel clips tolerates salt and moisture better than a painted steel housing. With a headroom of 2.1 to 2.4 metres, pay attention to impact resistance: a van with a roof rack hits a low luminaire sooner than you think. Mount between the ceiling beams or tight against the underside of the slab, never below the beams.

The TRIVO range is built for this: waterproof linear luminaires in IP65 and IP69K from 20 to 60 W, 140 to 150 lm/W, opened without tools and through-wired. The 20 W version with 2,800 lm is enough for parking bays under a low ceiling; for lanes and ramps you choose 40 or 60 W.

Motion sensors and night mode: from 24 hours at full power to 20 percent

A car park is lit 8,760 hours a year, mostly with nobody driving. A luminaire with a built-in microwave sensor sees through the diffuser and detects a car or pedestrian several metres away. Without movement the luminaire dims to a standby level of 10 to 20 percent. Never switch off completely: a dark car park feels unsafe and the cameras see nothing.

Worked example for one 60 W linear luminaire: running continuously costs 526 kWh a year. With a sensor giving full light 30 percent of the time and dimming to 20 percent for the other 70 percent, the average power drops to about 26 W, or 230 kWh. With these assumptions that is a saving of more than 55 percent, every year; the actual saving depends on how busy your car park is.

Set the sensors per zone, not per luminaire. Group lane segments of 15 to 20 metres so that the light runs ahead of the car. A hold time of 1 to 3 minutes on the lanes and 3 to 5 minutes in the bays stops someone loading their shopping from standing in the dark. With the remote control for the sensor settings you set hold time, dimming level and daylight threshold without opening the luminaire. If you want a fixed night mode, a time schedule or a link to the building management system, choose the DALI-2 version and set a reduced level per group, for example between 23:00 and 06:00.

Lighting plan: how many luminaires do you need

Indicative rule of thumb for an enclosed car park with grey concrete and a ceiling height of 2.5 to 3 metres: one linear luminaire of 6,000 lm per 25 to 30 m² of floor achieves the 75 lux, including a maintenance factor of 0.8. A white ceiling and light walls noticeably reduce the number of luminaires.

Run the linear luminaires lengthways along the lane, at its edge, so that the light falls on both the lane and the bays. Allow for beams, services and sprinkler heads: a 40 cm beam throws a shadow across an entire bay.

Areas with a higher ceiling, such as an entrance zone, a ramp under a void or a parking deck under a tall roof, are lit with the linear luminaires from the ATRIA range: the low bay adjustable from 14 to 75 W with DALI for ceilings of roughly 4 to 6 metres, or a 100 W linear high bay above that. If you are unsure about quantities, have a lighting calculation made: for 350 euros excl. VAT you receive lux values per zone, the uniformity and a parts list.

Through-wired installation: how to do it quickly

A car park soon has hundreds of luminaires, so the installation time per unit determines your margin. Through-wired linear luminaires have a cable entry at both ends, so you loop the supply from luminaire to luminaire without junction boxes. Use 5-core cable with DALI-2 (line, neutral, earth and two DALI cores); 3-core is enough with a built-in sensor.

How many luminaires fit on one circuit is determined not by the nominal power but by the inrush current of the drivers. A C-curve circuit breaker tolerates that peak better than a B-curve; calculate the run for voltage drop and inrush current.

A working order that proves itself:

• Set out the clips with a laser line, all at the same height.
• Pull the cable through all the luminaires in a row before closing the diffusers.
• Set the sensors per segment straight away with the remote control, before the access platform moves on.
• Mark the circuit number on each luminaire for the maintenance engineer.

Maintenance and service life

Dust, soot and brine settle on the diffuser and cost light output. Plan an annual cleaning round and do not use solvents on polycarbonate. An LED linear luminaire typically achieves 50,000 operating hours or more; at full power 24 hours a day that is almost six years, and considerably longer with sensor dimming. Lichtplein gives up to 5 years warranty on luminaires.

At handover, record which luminaires are on each circuit and keep 2 to 3 percent of the quantity as spares on site. After a collision the operator then does not have to wait for a delivery; reorders ship from European stock within 5 working days.

Frequently asked questions