Clarified assignment, questions asked in time and careful comparison of competing offers or alternative solutions, all of the above increases the likelihood that you are purchasing a solution that will fulfill your expectations. However, comparing industrial lighting proposals is a complex and, for the layman rather complicated task. Yet, it can be handled without having to penetrate too deep into the mysteries of the world of sensors and diodes.
It is enough to pay close attention to details and request appropriate documentation and facts for each supplier’s claim.
What is a lighting design projection and how to assess it
Lighting design projection is a document that shows how many luminaires should be used and how they are deployed. Apart from a large quantity of data, calculations and tables, the lighting-technical proposal contains a visualization of the area with graphs of illumination intensity and luminous flux. Usually, the proposal is processed in several variants, mapping the solution in response to changing parameters, respectively requirements.
Lighting design projection is processed in one of the specialized programs for lighting projects (DIALux, Relux, Wills). The plan of the selected area is imported into the program, including all the obstacles. Then, so-called EULUM data of planned luminaires are imported. It is a collection of data on luminaires light distribution characteristics, luminous flux efficiency, power consumption and so on. Then, the program calculates and shows the lighting levels, distribution and uniformity of the illumination, areas with the risk of glare and similar.
The manufacturer provides EULUM data for every type and wattage of its luminaires, using a reputable photogoniometric laboratory. Request EULUM data for your project.
The offer under consideration may be recalculated by an independent consultant. The recalculation, which represents an expense of a few thousands crowns, can prevent the loss of hundredths of thousands. What can an independent consultant discover?
- Whether delivered EULUM data really belongs to the planned type of luminaire, not to a different version with, for example, no cover or lower ingress protection, which shows better, but false parameters.
- Whether the author of the proposal took into an account all machines, beams, columns and other objects shielding or reflecting light. If the lighting-technical calculation does not include them, the conclusions will be significantly altered.
- Whether the author works with certified tables for light reflection from various surfaces of walls, ceilings or floors. Also, poorly-mapped surfaces significantly distort the results of the calculation. To compare multiple offers, reflection assumptions must be the same, otherwise the comparison is impossible.
- Whether the author considered the maintenance factor. Maintenance factor shows for how long the declared level of lighting will be observed in the expected operations. It is easy to achieve required illumination levels right after the installation, but it is significantly more difficult to maintain after a year or two in operation. Reputable supplier counts with the maintenance factor.
Should the re-calculation show any irregularities, require the payment from the author of incorrect proposal.
Luminaires’ technical parameters
There are a large number of various luminaires available on the market, but only a very small portion is designed for industrial conditions. Therefore, in the offers there may be fixtures made from plastic, open fixtures without ingress protection, inefficient and thus totally inappropriate, as well as luminaires that are of high quality, efficient, and thus truly industrial.
- Exclude offers that will be presented to you without prior consultation and inspection of operations.
- Consult with applicants, let them comment on the conditions of your operations, allow them to argue their offer and ask about their arguments. Clarify your idea for the optimal solution and supplier. Define your basic minimum requirements that will be binding for the supplier.
- Ask the candidates to submit the data sheets not only for lighting fixtures, but also for the components used in them. Check that they correspond to the candidate’s offer.
The installation realization, optionally automated control system
- Ask for the calculation, whether it is worth installing automated lighting control system. If it does not bring additional savings, the investment is difficult to defend.
- Clarify your vision and define basic parameters of the installation: a number of controlled zones, number of control stations, should the control be step-based or fluent. Aforethought list of requirements may be demanding, but the energy invested in it will bring you satisfaction and peace of mind.
The assessment by reference
Ask for references. Not only for the most recent ones, but also for few ones older than 3 years. Find the time to talk to referring customers about their long-term experience with the solution.
The role of external designer, consultant
You may come to the conclusion that the offer assessment requires a specialist, and you entrust the whole project to your in-house or external independent designer. He performs the calculations and proposes his own solution. Subsequently, you only ask potential suppliers of luminaires and installation – and you have your win.
Unfortunately, it does not have to be the case. Even though the designer makes careful calculations, with the best interest in mind, he chooses the specific type of luminaires and specific type of control, he may miss a better, more efficient, cheaper or more powerful solutions. Here in doublepower, we deal with lighting every day, and we do not dare to say that we know in detail the entire market. Likewise, your designer may not know it.
Therefore, you should undergo a selection procedure also for the solution designs. This does not diminish the role of your designer, just the contrary. Ask him to help with formulating the assignment and the definition of space for lighting- design projection. He will supervise professionally that all the obstacles and reflections factors are contained in the proposals.
Only an objective assignment with the same conditions for every applicant can provide comparable offers and help you to choose the best one.