Lumeitalia

How to compare two technical bids for ATEX and harsh environment lighting

A method for reading ATEX and harsh environment lighting bids side by side: what is comparable, what is not and where the differences hide.

Studio illuminotecnico con planimetria, ottiche e simulazione della luce
Studio illuminotecnico con planimetria, ottiche e simulazione della luce. Immagine illustrativa generata con AI.

Overview

Two bids with the same luminaire count and installed power can describe profoundly different installations. Where potentially explosive atmospheres exist, a luminaire is not just a light source: it is a safety component tied to hazardous-area classification. This methodological comparison by Centro Studi Lumeitalia explains how to read two ATEX and harsh environment lighting proposals in parallel without stopping at price.

Applicable standards

The regulatory reference for ATEX and harsh environment lighting is not a single document but a coordinated set of standards covering performance, safety and environmental impact. In design practice the following documents drive the main choices.

  • Directive 2014/34/EU (ATEX) — equipment for explosive atmospheres.
  • EN 60079 — protection modes for gas and dust.
  • EN 12464-1 — lighting requirements of the activity performed.

Bringing bids onto a common basis

The first step is checking that both proposals assume the same requirements, the same geometry and the same maintenance factor. If one calculates for a new installation and the other at end of life, comparison is impossible until the assumptions are realigned. The same check applies to annual operating hours and the planned dimming profile.

In ATEX and harsh environment lighting projects, differences frequently arise from a different reading of site conditions: clarifying this point in writing is worth more than any comparison table.

Where the differences hide

  • Photometry — File of the proposed luminaire, not an equivalent — Calculation not reproducible
  • Maintenance factor — Value and associated cleaning cycle — Below-target performance at end of life
  • Control — Protocol, dimming curve, signal-loss behaviour — Declared savings not achieved
  • Protection — Coordination and declared withstand — Premature failures outside warranty
  • Maintenance — Cycles, access, spares and lead times — Operating cost above budget
  • Warranty — Duration, exclusions, validity conditions — Unplanned burden on the client

From price to cost of ownership

A meaningful economic comparison spans the whole operating period: initial investment, annual consumption under the planned dimming conditions, cost of planned maintenance and an estimate of replacements. Energy price and inflation assumptions must be declared: changing them changes the outcome, and undeclared they make the comparison non-reproducible.

The selection criterion must be written before bids are received. Setting parameter weights afterwards is the practice that generates the most disputes in comparative procedures.

Recurring critical points

The difficulties that most often emerge in ATEX and harsh environment lighting projects are not about product selection, but about defining requirements and verifying results.

  • Correctly matching hazardous zone, group and temperature class.
  • Allowing maintenance without compromising the protection mode.
  • Resisting chemicals, salt spray and washdown cycles.

Design approach

An orderly method drastically reduces variations during works and disputes at commissioning. Three choices make the difference from the earliest stages.

  • Luminaire selection starting from the explosion protection document.
  • Maintenance procedures preserving certified gaskets and torque values.
  • Corrosion-resistant materials for offshore and chemical plants.

Parameters to verify

  • ATEX zone — Directive 2014/34/EU — 0/1/2 for gas, 20/21/22 for dust
  • Protection mode — EN 60079 — consistent with the classified zone
  • Temperature class — EN 60079 — compatible with the substance present
  • Lighting requirements — EN 12464-1 — defined by the visual task

Most frequent mistakes

Non-conformities found at commissioning almost always come from three causes: requirements not declared or declared without a reference standard, calculation run on idealised geometry, and an optimistic maintenance factor. All three can be avoided at zero cost during design.

  • Same assumptions on requirements, geometry and operating hours
  • Maintenance factor aligned across proposals
  • Photometric files of the luminaires actually offered
  • Maintenance and spare-part items quantified
  • Economic assumptions (energy, inflation) declared
  • Selection criterion defined before bids are opened

Key takeaways

A ATEX and harsh environment lighting project holds up over time when requirements are declared, the calculation reproduces real conditions and on-site verification follows an agreed protocol. Component selection matters, but comes later: without measurable requirements even the best product delivers a result that cannot be demonstrated. Centro Studi Lumeitalia makes its technical office available to review requirements and design checks.

Methodological note: This content is written for technical information purposes by Centro Studi Lumeitalia and does not replace the lighting design or a full reading of the standards cited. Applicable performance values are those of the standards in force at design time.

Domande frequenti

Who defines the ATEX zone of a plant?+

The employer, through the explosion protection document drawn up with competent technicians: the luminaire is chosen after that classification.

Is an IP66 luminaire automatically ATEX-suitable?+

No. IP rating covers dust and water, while ATEX suitability depends on the certified protection mode and specific marking.

Where should a ATEX and harsh environment lighting project start?+

From a written definition of performance requirements and verification conditions: this step drives every later choice and makes the result either disputable or defensible at commissioning.

Which documents should be requested from the supplier?+

Photometric files of the proposed luminaires, declaration of conformity, lifetime data declared per IES LM-80 with its conditions, the maintenance schedule and warranty terms.