MR16 LED retrofit lamps : quality, consistency and reliability : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Environmental Technology & Sustainable Energy at Massey University, Albany, New Zealand
Light-emitting diode (LED) MR16 lamps have recently become part of the
residential lighting market, bringing with them a new lighting paradigm.
Consumers previously accustomed to halogen MR16 technology must now
select suitable LED replacements based on their photometric information. In
the wake of stories of exaggerated lumen outputs and inaccurate marketing
literature, this research takes a snapshot of MR16 LED residential lighting in
New Zealand to evaluate its status.
Forty-eight readily available products (six repetitions of eight types) were
tested in Massey University's integrating sphere. Initial investigations focused
on baseline photometric values to determine whether claims of halogen
equivalency were justified and if manufacturers’ photometric information was
valid. Lamp quality was checked using ENERGY STAR as a basis, and
variation across each six-lamp sample was checked to determine whether
consistency could be assured to the consumer.
The effect of heat on LEDs was investigated through a 6,000 hour test. This
saw groups of lamps running continuously in both downlights and free air in a
simulated residential installation in Auckland, New Zealand. As well as
analysing whether such mounting arrangements caused different levels of
non-recoverable deterioration over time, the study also considered the
general behaviour of all lamps over the test period.
The study had mixed results, and revealed that care must be taken when
purchasing MR16 LED lamps in New Zealand due to these varied levels of
Significantly, one lamp type was found to mechanically deteriorate over time
such that it proved a fire risk. This was exacerbated by high temperature and
the lamps mounted in downlights deteriorated 2,000 hours before their free air
equivalents showed signs of similar behaviour.
With 25% of the lamps sampled in the study shown to be seriously flawed, it
is clear that appropriate regulation is required in order to ensure that MR16
LED lamps sold in New Zealand are fit for purpose.
The study concludes by suggesting further areas for research which were
limited by time constraints. All of these proposed investigations would enrich
the existing findings.