Page 85 - Hong Kong Green School Guide

3. Green School Guide - 3.3 Energy Saving
Hong Kong Green Building Council 83
Window Type Split Type Variable Refrigerant
Flow (VRF) Type
Cost Low Moderate High
Serve area per
unit
Small Area Small Area Large and multiple
spaces
Installation
complexity
Simple Moderate Complex
Installation space A portion of
window
Wall mounted or
ceiling mounted
indoor unit.
Outdoor unit
can be mounted
on external wall
or small area of
flat ground.
Wall mounted or ceiling
mounted indoor unit.
Outdoor unit requires
large area of flat ground.
Efficiency Relatively Low High (inverter)
Medium (non-
inverter)
High
Estimated Annual
Energy Saving
Compared to
Window Type
N/A 60 kWh/m2 of
air conditioned
area
(25-Watt light
bulb for 2,400
hours)
100 kWh/m2 of air
conditioned area
(25-Watt light bulb for
4,000 hours)
* Comparison provided above is not exhaustive. Please consult registered
professional and/or contractor for detailed comparison and installation options.
• When purchasing an air conditioning unit, look for energy labelled units (such
as EMSD Energy Label Grade 1);
• Some Variable Refrigerant Flow (VRF) units are rated by US EnergyStar
and/or European EU Energy Label. When purchasing VRF units request for
contractor source units rated by US or European energy labelling schemes;
• Set up an interlocking system that only allows user to turn on air conditioning
systems at set temperature and humidity;
• Use environmentally friendly refrigerants: R410A, R134A, R600A, etc.; and
• Do not use refrigerants that are not environmentally friendly: R12, R22, etc.
Professional Help
• Registered Professional Engineer (RPE) – Appendix A (4)
• Registered Air Conditioning Contractors – Appendix B (1)
Cost Information
Schools can contact air conditioner contractors for costs and options.