Three categories of ECMs, namely major
investment ECMs (variable air volume (VAV) systems against constant air volume (CAV); and low coefficient
of performance (COP) chillers against high COP chillers); minor investment ECMs (photo electric
dimming control system against general lighting, and double glazed low emittance windows against
single-glazed windows) and zero investment ECMs (reset heating and cooling set point temperatures)
are evaluated.