5.1.7 HVAC saving measures
Some common HVAC saving measures and the difficulties that may be encountered in implementation are listed in
the following table for easy reference.
Saving measures for space conditioning and potential energy reduction
Saving measures for space conditioning
Difficulties
Energy reduction (%)
Increase chilled water supply temperature by 2°C
Easy and immediate.
3 – 6 (chiller)
Increase space temperature by 2°C
10 – 20 (air-conditioning system)
Regular maintenance of chiller
(e.g. tube cleansing, water treatment)
Easy and immediate.
It depends on the existing
conditions and it may
require minimal expense
to improve the access or
maintenance facilities.
10 – 30 (chiller)
Regular maintenance of air-side system
(e.g. filter replacement/cleaning, coil cleaning)
5 – 20 (fan)
Regular system calibration, testing & balancing,
re-commissioning
5 – 20 (air-conditioning system)
Optimum fresh air flow rate
Easy for new project.
For an existing
shopping mall, it can
be implemented during
annual comprehensive
maintenance.
5 – 10 (power)
Proper air balancing including fresh air dampers
5 – 15 (air-conditioning system)
Use of
(as against air cooled chiller) Easy for new project.
For existing shopping
mall, it may be
implemented during plant
retrofit or shopping mall
renovation.
40 – 50 (chiller)
Variable speed drive chiller
20 – 30 (chiller)
Variable chilled water flow
10 – 30 (pump)
Optimum chiller operating efficiency & configuration
10 – 40 (chiller)
Appropriate chilled water control valves &
proper water balancing
10 – 25 (air-conditioning system)
Optimum chilled water pipe diameter
5 – 10 (pump)
Optimum chilled water pipe insulation
3 – 10 (air-conditioning system)
Minimize air leakage at ductwork, access panels, etc.
1 – 3 (air-conditioning system)
Variable speed drive
10 – 30 (fan)
Free cooling design
5 – 15 (air-conditioning system)
5.1.8 Professional help
It is important to engage professionals for detailed consultation on the implementation of heating, ventilation and
air-conditioning (HVAC) at shopping malls and shop spaces. The following is a list of references for obtaining
professional help:
• Registered professional engineers (RPE) in the building services discipline – Appendix A (4)
• Registered air conditioning contractors – Appendix B (1)
5
Energy efficient building systems for shopping malls and shop spaces
5.1
Heating, ventilation and air-conditioning (HVAC)
130 Hong Kong Green Shop Guide
