In today’s commercial environment operating costs are continuously being scrutinised and squeezed.  Lighting is no exception.  Whilst requirements are continuously rising and may vary from application to application, they do have one thing in common: the need for reduced total cost-of-ownership.  It is no longer an option to consider the initial install cost. Indeed, customers today are becoming more interested in whole life costing which is why cradle to rebirth lighting solutions are so important.  These solutions include design capability, refit capacity, best practice planned lighting maintenance plus a premium recycling offer where up to 98% of components of lamps are re-used by manufacturers such as Philips.

All of this coupled with additional energy saving expertise guarantees customers optimum illuminance in the most cost-effective manner.

Commercial viability

Given this backdrop, the continued use of out-dated 8ft fluorescent tube technology would seem impractical and, above all, highly uneconomic.  However, the UK is the only country in Europe where this short sighted practice still continues.  This is unfortunately due to the fact that many users find it easier to replace what there was before rather than assess the larger economic picture by adopting newer, more environmentally friendly and more commercially viable options. For manufacturers producing high volume runs to meet the sizeable demand throughout Europe, this presents a further dilemma weighed up against a UK market of only ½ to 1 million pieces. Reluctance to switchover factory production lines for a short run burst is therefore hardly surprising!

Environmental drivers

Not only that but with the demand on manufacturers to become increasingly environmentally  responsible, it does not make sense to produce lamps which in actual fact require a high level of mercury in their composition in comparison to other greener lamp alternatives.

This also raises the question as to how to dispose of the lamps once they have come to the end of their useful life.  As we know, environmental legislation is becoming increasingly strict on how this is done.  The Waste Electrical and Electronic Equipment Directive (WEEE) is currently being implemented throughout Europe and will bring with it even more rigorous requirements.

There are two elements to the aims of WEEE with regard to lamp disposal. One is to encourage the recycling of the components that are used in the manufacture of lamps. The second is to ensure that dangerous substances such as mercury, found in virtually all discharge lamps, is disposed of responsibly.  Indeed the RoHS directive goes further than this by banning the placement on the EU market of new electrical and electronic equipment containing more than the agreed levels of certain hazardous substances including mercury. Ironically 8ft fluorescent tubes have been made exempt from this ruling despite needing approximately 10mg of mercury in production! This is compared to more environmentally friendly lamps such as Philips Master TL5 which have the lowest mercury content of between 1.4mg and 3mg on the market.  

Practical issues

Typically 8ft fluorescents are found in the industrial sector where ceilings are in excess of 20 -30 feet such as in factories and warehouses for example.  Installation of the lamps is expensive since the unwieldy size requires a two man operation, which brings with it increased labour costs. Even before installation, the lamps are an expensive proposition since additional storage at wholesalers’ premises is needed to house a relatively small amount of stock.  As any wholesaler will know shelf space is a valuable commodity and should be utilised for its optimum return on investment: smaller, more profitable lamps with a high turnaround in demand. 

Cost of ownership

For the end user the cost of ownership argument becomes even more persuasive when compared to other lamp options available.  For example a 100 W Colour 35 8ft halophosphate fluorescent lamp can only be used on switch start gear and has an average service lifetime of between 1-1½ years.   Weigh this up against the fact that a new generation fluorescent lamp such as the Master TL-D 70 W Colour 80 can be used on High Frequency gear therefore giving savings of up to 40% energy. It will also often give the same if not more light output and conforms to the building code EN 12464-1 which the 100 W does not.  In addition it has up to a 50% increase in service life! The argument becomes even more compelling given the fact that the Master TL-D lamps cost less from the outset.

Figure 1 illustrates this in more detail. As can be seen, albeit that this does not include the initial material and labour costs of changing the lamp fixture, the payback is immediate and averages over £18 savings per year per lamp.  Looking at the yearly energy savings alone, which equate to £16.80, this would also mean a CO2 saving of 0.12 ton per year using DEFRA figures of 0.43kgCO2/kWh.

A further advantage in user comfort when installing Master TL-D lamps is that the HF gear needed for them means that there is no lamp-end flickering, smooth and rapid lamp starting is ensured so potentially dangerous stroboscopic effects can be avoided.  Moreover, HF gear allows for controls to be used providing more energy savings to be made by adopting techniques such as presence detection and daylight sensors. 

New lamp developments

Whilst we have detailed here comparisons with Master TL-D lamps, product development continues to move on apace. The introduction of Master Xtra and Xtreme lamps directly responds to the issues surrounding high ceilings and difficult to reach applications, the traditional home of the old 8ft options.

This new breed of lamps offers maximum benefit to owners and/or maintenance companies bearing the cost of maintenance. When used with electromagnetic control gear, for example, the 90% survival rate for the Xtra is 21,000 hours and for the Xtreme is 36,000 hours:- and will be even longer when used with electronic gear. Thus, as a result of their outstanding lifetime reliability significantly less early failures will occur reducing the frequency for replacements and all the associated costs involved. Also the indirect costs for production stops or disturbances to workflow need to be taken into account.  Although these are often difficult to estimate, they should not be neglected.

Other developments include lamps with integral reflectors. Since the light of a conventional fluorescent lamp is radiated in all directions, only half of the available light falls on the work place. The other half is largely wasted.  This has been addressed by introductions such as the Master Reflex lamp with its in-built reflector which directs up to about 80% of the light downwards.  This has a twofold benefit of achieving the same lighting level with fewer lamps and also that the lamp is unaffected by dirt accumulation on the top surface therefore less frequent cleaning is necessary.

Essentially, the standard Master TL-D lamps and these more recent product developments meet the need for a more responsible approach to our environment but not at the expense of quality and performance.   For the forward thinking the benefits can be immense.  Whilst some of these new products may be initially of high value, such features as their reliability and therefore their predictable failure rates can increase profitability.  For the end user they have the assurance that they will enjoy better lighting with true costs of ownership that are at an all time low. What value 8ft fluorescents?