19-02-2013, 09:44 AM
Replacing conventional magnetic ballasts
Introduction
The hospital in this case is a medium-sized institution with most of the lighting
consisting of fluorescent tubes. However, there is no overview of the total energy
consumption of the lighting. This makes it difficult to arrive at a precise
calculation, but the potential savings can nevertheless be estimated on the basis
of reference data.
Present situation
An estimated 70% or so of the lighting is currently equipped with obsolete,
conventional magnetic ballasts. As already explained, such magnetic ballasts are
responsible for considerable energy losses (around 20%).
Proposal
By using energy-efficient light fittings with electronic ballasts, the ballast losses
can be reduced and energy can be saved on the lighting.
Estimated savings & investment
There is no overview of the number of lighting fittings or the energy consumption
of the lighting installation. However, based on data from previous studies and
from the literature it is estimated that in an average hospital lighting accounts for
some 20% of the total energy consumption. For the hospital in the case study
this means that some 2 400 MWh of the annual electricity consumption is due to
lighting. This value was first verified on the basis of the total floor area, by
determining the installed power per m² per 100 lux, which confirmed the
estimate. The savings potential was then calculated as follows:
The percentage of conventional fluorescent lighting fittings with conventional
ballasts is around 70%. It was further assumed that 90% of the total lighting
consists of fluorescent tubes. The majority of the fittings have white enamelled
reflectors.