Making decisions in the right light

When specifiers and their clients are considering lighting upgrades it’s important to base the decision on the most appropriate criteria for each project, rather than simply following the market trends. Sam Hawkes of Riegens Lighting explains.

Many building operators will be aware that if they have an ageing lighting installation they can almost certainly achieve substantial energy savings by upgrading to newer lighting. The dilemma for some though is what lighting solution to upgrade to – as there are now so many options being flagged up in the press and elsewhere.

In many cases they will rely heavily on the guidance of a building services engineer, so it’s important that the latter discusses all of the options and their implications, even when the client has stated a preference. Even the most informed client may not be aware of all of the options available, or have sufficient knowledge to take a holistic view across the lifecycle of the lighting installation.

A good example of this is the awareness of LED lighting amongst clients, often leading them to cite LED as their first preference. This may be simply because they’ve read a great deal about the undoubted benefits of LEDs. Or they may be letting agents who see LED lighting as being more marketable than other forms of lighting.

However, there are some situations where T5 fluorescent lighting will still give LEDs a run for their money, in terms of energy performance, lighting quality and lifecycle costs. Bearing in mind that LED light engines typically cost more than a linear or compact fluorescent lamp, but to that end, it’s interesting to compare the overall costs of a high quality T5 lighting system with those for an LED system and the return on investment that can be expected.

Fast payback

In the light of this price differential, it can take a significant reduction in energy costs to compensate sufficiently to deliver a fast payback. So clearly the type of lamp that is being replaced in the refurbishment is important. If a 50w halogen lamp is being replaced with a 7W LED the reduction in installed electrical load would deliver an acceptable return on investment.

This situation is quite different when replacing fluorescent light sources with LEDs. Indeed, there are some 600mm x 600mm LED fittings on the market that will consume as much power as a 600mm x 600mm fluorescent fitting.

In these cases, factors such as reduced maintenance costs due to longer lamp life come into play. Some LED manufacturers claim a 45,000 (we claim 50,000) hour life for their lamps and that is certainly impressive. However there are also special premium T5 lamps that claim the same. And the standard T5 lamps from quality manufacturers will deliver nearly 20,000 hours.

In these circumstances it’s necessary to calculate whether the maintenance savings sufficiently offset the extra cost of the LED lamps. For example, office lighting is typically replaced every six to seven years, so it’s worth questioning the value of a high capital cost installation in relation to its projected life. In retail applications the life of the lighting is likely to be more like two to three years before the store gets a make-over, so there may be even less justification.

Dynamic solution

This isn’t to say that LEDs should not be considered. Rather, it’s important to see LEDs as one option that can be proposed to the client, in the ‘light’ of their requirements. For instance, if a project requires a dynamic lighting system that changes with seasons, time of day or particular events then LEDs will almost certainly be a better option than fluorescent. LED technology enables the creation of a ‘tunable’ dynamic white light system where colour temperature can be varied between 2700K and 6500K, in combination with different lux levels. Such a system can also be controlled very easily through a DMX or DALI network, providing a better solution than the pre-LED approach of varying light outputs from different colour temperature fluorescent lamps.

As a company that manufactures both LED and T5 fluorescent lighting systems we don’t have a particular axe to grind especially as there is no doubt that LED is the future. But we do see many situations where a client is asking for an LED solution without having considered other options and the specifier simply goes along with that.

In my experience, clients actually like to be given the full picture and don’t mind having their preconceptions challenged with sensible arguments. At the end of the day, it will be their lighting system for many years so they want to ensure they get the best value from it.

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