Energy Saving Tips



The unit to measure electricity consumption is the “Watt” (W). The higher the number of “Watt”, the more electricity will be consumed. You can find the “Watt” indicated on most electrical appliances.


Electricity consumption is represented by unit of kWh (kilo-watt per hour) on the electricity bill. 1kWh is equal to 1,000 Watt being used in an hour.


1kWh of electricity = The use of the following appliances:

Steam iron (1,500W)     for 40 minutes
Hair dryer (1,200W) for 50 minutes
Air-conditioner (1,000W) for 1 hour
Washing machine (400W) for 2.5 hours
Notebook computer (135W)   for 7.5 hours
Fan (50W) for 20 hours
Lamp (25W) for 40 hours

Remark: The energy consumption figures for the above electrical appliances are for references only.


Want to know how to conserve 1kWh of electricity?

The following tips can help you easily save 1 kWh of electricity in your daily activities:

  1. By eliminating the use of a 1,000W air-conditioner for 1 hour, you can save 1kWh of electricity! (The power consumption of a 1 horsepower air-conditioner is around 850-950W.)
  2. Keep a desktop computer with LCD monitor (180W) and a notebook computer (135W) operating for 6 and 8 hours respectively will consume 1 kWh of electricity each. Remember to turn off the computer before bedtime can save 1 kWh of electricity!
  3. Use the washing machine only when there is a full load of clothes. Take a 500W washing machine as an example: eliminate the use of the machine for 2 times (assuming 1 hour each time) can save 1 kWh of electricity!
  4. The electricity consumption of clothes dryer is four times higher than that of a washing machine on average. Reduce the use of clothes dryer for 30 minutes can save 1 kWh of electricity!
  5. Avoid leaving audio visual systems in their standby-mode. Turn off a television (345W), a stereo set (200W) or a DVD player (20W) when not in use instead of switching to standby-mode can save 1 kWh of electricity in just 2 days! (Based on standby-mode consumes 5% of the total electricity.)
  6. Purchase clothing that is made of wash-and-wear fabrics. Reduce the use of steam iron (1,500W) for 40 minutes can save 1 kWh of electricity!
  7. Avoid washing hair just before bedtime to let hair dry naturally instead of using hair dryer. Reduce the use of hair dryer (1,200W) for 7 minutes a day, you can save 1 kWh of electricity in just a week’s time!
  8. Most electric oven is at least 2,500W. The cooking time for steaming or boiling is usually much shorter than baking. Reduce the use of electric oven for 25 minutes can save 1 kWh of electricity!






Energy Saving Tips for School


Concepts and Principles
Energy saving results from conscious efforts to reduce energy consumption.There are four main categories for energy conservation for a school environment:

  1. Climate Positive Design
    Designs such as window films, double glazing window, blinds and curtains, solar tube and other climate positive designs (also known as passive designs).
  2. Energy Efficient System
    EMSD Grade 1 energy labelled air conditioning units, occupancy sensor controlled lighting, LED lighting, heat pump water heaters, EMSD energy labelled appliances, etc. are considered energy efficient system which can meet the occupancy demand in an energy efficient way.
  3. Renewable Energy System
    Adoption of renewable energy sources, such as solar and/or wind energy contributes positively to energy demand of schools and serves educational purposes.
  4. Energy Management
    Another major component of energy conservation is to monitor and manage energy demand by using energy and/or smart metering for major building systems in order to record the system performance especially in implementation of green initiatives and student participation in monitoring their behavioural impact on energy usage.

The following are summaries extracted from the Hong Kong Green School Guide.
For details, please refer to the document at http://www.hkgbc.org.hk/eng/greenschguide.aspx


Energy Saving Measures

  1. Window Films
    • Reduce heat gain through window, hence energy requirements for air conditioning; and
    • Improve thermal comfort near the window area
  2. Double Glazing
    • Reduce heat gain through windows, hence lower energy requirements for air conditioning (estimated annual energy saving is 130 kWh/m2 of air conditioned area for the difference between double glazing and single glazing. This is equivalent to a 25-Watt light bulb for 5,200 hours’ operation);
    • Improve thermal comfort near the window area; and
    • Improve acoustic insulation and therefore reducing noise transmission from outdoors.
  3. Blinds, Curtains and Automatic Control
    • Reduce heat gain through windows by lowering the blinds / curtains, hence lowering energy requirements for air conditioning;
    • Improve thermal comfort near the window area;
    • Reduce glare to occupants with the help of blinds and curtains controlled by daylight sensor control; and
    • Automatic control to prevent blinds / curtains from being shut when daylight is sufficient for lighting indoor area.
  4. Solar Tube & Heliostat
    • Reduce energy demands created by artificial lighting;
    • Direct daylight to areas with limited daylight access (e.g. area far away from window);
    • Studies show that humans performs better and are healthier under natural daylight compared to artificial lighting; and
    • Good demonstration project for students and other building occupants.
  5. Air Conditioning Units
    • Reduce energy consumption with energy efficient air conditioning units while achieving desired thermal comfort; and
    • Reduce damage to ozone layer and global warming impacts by selecting air conditioning units that use environmentally friendly refrigerant.
  6. Energy Efficient Lighting and Smart Control
    • Energy efficient lighting reduces energy consumption while also providing adequate illumination; and
    • Automatic lighting controls (e.g. motion & daylight) reduce unnecessary use of artificial lighting and related energy consumption.
  7. Heat Pump Water Heaters
    • Provide heating (hot water) and cooling (air conditioning) in one unit; and
    • Compared to conventional electrical/gas water heaters, heat pump water heaters are more energy efficient and can result in 30-50% energy reduction. For every litre of hot water, the saving is the same as a 25-Watt light bulb for operating for one hour.
  8. Energy Efficient Lift
    • Reduce energy consumption through the use of energy efficient lift system; and
    • Lifts with regenerative motors can output electricity back to the building grid when the lift is going downward. The electricity generated over one year by a typical lift fitted with a regenerative motor is sufficient for 100 25-Watt light bulbs to operate for a year.
  9. Energy Efficient Appliances
    • Reduce energy consumption;
    • Simple step to reduce energy carbon emissions; and
    • Promote behavioural change and education for staffs and students.
  10. Solar Hot Water System
    • Utilize ‘free’ resource in the form of solar energy to heat water;
    • Reduce carbon emissions generated through heating water by other means;
    • Practical feature that can provide hands-on-learning experience for students to learn about renewable energy; and
    • 800 kWh electricity per m2 of solar panel area can be saved through solar heating of water per year. This is equivalent to operate a 25-Watt light bulb for three and a half years.
  11. Wind Turbine
    • Utilise wind as a ‘free’ resource to provide energy;
    • Visible feature to demonstrate the school’s green initiatives to the public; and
    • Practical feature for students to learn about renewable energy, for example, by observing the energy produced from the wind system (e.g. via energy meter connection or use for specific lighting area).
  12. Photovoltaic Panel
    • Utilise a ‘free’ resource in the form of solar energy for electricity generation on site;
    • Valuable demonstration project to showcase the school’s green initiatives;
    • Practical feature for students to observe energy produced by the system (e.g. via energy meter, or connection to lighting system for specific area) and to learn about renewable energy; and
    • PV panel can generate electricity around 170 kWh/m2 of panel area per year. This is equivalent to powering 25-Watt light bulbs for 6,800 hours in ideal conditions.
  13. Energy Meters
    • The provision of energy metering encourages students and teachers to monitor their school energy usage, and provide data on how their behavioural changes (and weather conditions) can impact on energy consumption;
    • With the provision of energy meters for different systems, the energy usage and strength of individual system can be easily identified; and
    • Provide indication of actual energy performance and energy reduction after implementation of green initiatives.

Efficient Operation of Air Conditioning Equipment

  • Adjust the room temperature to 25.5oC;
  • Temperature set point for air conditioner can be 20C ~ 3OC higher with the supplement of wall / ceiling mounted fans, without sacrificing thermal comfort;
  • It is more energy efficient when the air conditioner and fan are turned on together to achieve the desired room temperature;
  • Doors segregating air conditioned and non-air conditioned spaces shall be closed;
  • Windows at air-conditioned spaces shall be closed when air conditioning is in operation;
  • Consider installing inverter split type air conditioners which are more energy efficient than conventional split type or window type air conditioners;
  • Clean cooling fins and air filters regularly to ensure air conditioners are operating efficiently;
  • Check regularly all automatic temperature controls to ensure they are operating properly; and
  • Consider locking the thermostats either at the desired setting or at a limited range of adjustment by the end-users.

Efficient Operation of Lighting Equipment

  • Switch off the lights close to windows to utilise day light; and
  • Clean light diffusers and reflectors regularly to keep lighting performance

Successful Cases from Schools


Tung Wah College (King’s Park Campus)

  1. Night & holiday mode for elevator.
  2. Slow speed mode for elevator during non peak hour.
  3. Promotion to encourage staircase walking.
  4. Meeting room allocation matches nos. of attendance.
  5. Patrol tour to ensure the lighting and A/C are turned off when space is unused.
  6. Re-arrangement of office space for teaching staffs.

HK Polytechnic University

  1. Upgrade the aged fan coil system.
  2. Inverter control based on multi-sensing input.
  3. Room Thermostat with lower temperature setting limit.
  4. All lighting circuits have 2 independent switchable loops.

Maryknoll Secondary School

  1. Upgrade 400 T5 light tubes using ECF.
  2. Very clear A/C usage guideline according to the weather condition.
  3. Embedded low-carbon education programmes in the teaching curriculum.

HKMLC Wong Chan Sook Ying Memorial School

  1. Clear A/C usage guideline according to the weather condition.
  2. Class ambassador responsible for fan/lighting control.
  3. Lunch with the classroom light turn off.
  4. Install auto-night off programme in the PC.

HKUGA Primary School

  1. Class ambassador responsible for fan/lighting control.
  2. Energy Saving competition during breaks.
  3. Poster to promote energy saving.
  4. Upgraded with T5 lighting.


Energy Saving Tips for Offices


Air Conditioning

  1. The recommended air-conditioning temperature set-point should be 25.5℃ for acceptable comfort conditions. Complement with the use of ventilating equipment and electric fans will lower electricity consumption substantially.
  2. By adjusting the air-conditioner temperature upward by 1℃, it could help to reduce about 3% of electricity consumption.
  3. Lower the venetian blind to avoid direct sun light in the summer.
  4. Keep windows and doors closed to minimize air infiltration when the air-conditioner is running.
  5. Turn off some or all air-conditioners 15 minutes before leaving the facility.
  6. Install frequency inverter for air conditioners.
  7. Turn off some air conditioners when room occupancy is low (e.g. on Saturdays or after normal office hours).
  8. Turn off the air conditioners when no one is in use.
  9. Clean or replace the filters in all air-conditioners regularly to improve efficiency.
  10. Establish a maintenance programme or schedule to ensure the air conditioning operates efficiently.
  11. Replace old, inefficient air conditioners with new, energy efficient models affixed with Grade 1 Energy Label.

Lighting

  1. Replace traditional light bulbs with compact fluorescent bulbs save as much as 70% to 80% energy per hour.
  2. Take advantage of natural sun light.
  3. Turn off lights when not in use and affix reminder message near the switch.
  4. Turn off some lighting when room occupancy is low (e.g. on Saturdays or after normal office hours).
  5. Avoid over-lit by artificial lighting for areas sufficiently lit by natural daylight.
  6. Turn off lighting in public areas (e.g. pantries, lavatories, circulation space etc.) during lunch and after office hours.
  7. Replace T8, T10 or T12 fluorescent lamps with T5 models.
  8. Retrofit fixed output lighting with dimmable lighting using low loss electronic ballast and photocells.

Computer

  1. Replace cathode ray tube (CRT) monitor with more energy efficient liquid crystal display (LCD).
  2. Set computers to sleep or standby mode when not in use.
  3. Turn off the monitor when leaving office, even for a short meeting. (“screen saver” does not save energy).
  4. Turn off the master switch for printers or other peripherals if not in use.

Server

  1. Maintain adequate air flow around computer equipment rather than trying to lower the room temperature to achieve a good heat dissipation. Monitor the room temperature of server rooms (e.g. by installing thermostats) to avoid excessive cooling.
  2. During the period of low power demand from servers, such as Saturday afternoons and public holidays, switch off some air conditioning in server rooms.
  3. When possible, turn off non-essential servers at night and non office hours.

Office Equipment

  1. Set office equipment to energy saving mode during office hours. Turn off after use.
  2. Unplug equipment chargers and adapters from socket outlets when not in use.
  3. Identify and repair/replace equipment that is not operating well such as flicking lights, noisy fans and water leaking air-conditioners. They are usually less efficient and consume more energy.
  4. Replace, where appropriate, electrical appliances and office equipments with more energy-efficient models affixed with Grade 1 Energy Label.
  5. Arrange for the last-man-out to check and turn off all air-conditioning, lighting and office equipment.

(Source from﹕EPD and EMSD)


Successful Cases from Organisation Category


Airport Authority Hong Kong

  1. Improve lighting efficiency for large spaces application from ~65 lm/W to ~100 lm/W.
  2. Advanced HVAC control strategy based on real time passenger flow.

Kwong Wah Hospital

  1. Heat Pump technology - utilizing HVAC exhausted hot air for water heating application.
  2. Great attention to the correct plant operation procedure and maintenance.
  3. Quality Management according to ISO14001.

HKT Limited

  1. Continue to upgrade the aged Voice network.
  2. Migrate onto the NGN server which reduces electricity consumption by 70%.
  3. 2 Telecom exchange plants switched to water cool chiller.

Viva China Holdings Ltd.

  1. Plenty of sub-control despite the air conditioning system is centrally supplied.
  2. Turn off lighting/ conditioned air supply during lunch break.
  3. Switch to LED lighting and de-tubing where appropriate.
  4. Energy saving reminder sticker on office equipments.
  5. Organize vegetarian lunch on a monthly basis.
  6. Demonstration and support from top management.

Christian Environmental Health Ltd.

  1. Engage all office staffs to a green office culture.
  2. Turn off PC/ monitor when leaving the staff desk.
  3. Last leaving staff will patrol the office.
  4. The warehouse is upgraded with Grade 1 air conditioner.
  5. Add simple timer to the exhaust fan.

Roche Hong Kong Ltd.

  1. Clear 5 year target plan to reduce electricity usage intensity.
  2. Formation of green group to promote energy efficiency.
  3. Adequate nos. of switches for fine on/off control of lighting/ HVAC.
  4. Switch to LED lighting and de-tubing where appropriate.
  5. Encourage work/ life balance and therefore reducing unnecessary OT.

Energy Saving Tips for Property Management


Air Conditioning

  1. The recommended air-conditioning temperature set-point should be 25.5℃ for acceptable comfort conditions. Complement with the use of ventilating equipment and electric fans will lower electricity consumption substantially.
  2. By adjusting the air-conditioner temperature upward by 1℃, it could help to reduce about 3% of electricity consumption.
  3. Keep windows and doors closed to minimize air infiltration when air conditioner is running.
  4. Install a frequency inverter for air conditioners.
  5. For crowded public areas, adjust to higher fan speeds to supply sufficient fresh air instead of lowering the temperature of the air conditioners.
  6. When the public area is not crowded, turn off some of the air conditioners.
  7. The air conditioners should be turned off 15 minutes before leaving the facility.
  8. Turn off the air conditioners when not in use.
  9. Clean or replace the filters in all air-conditioners regularly to improve efficiency. Such measure saves electricity consumption by as much as 30%.
  10. Establish a maintenance programme or schedule to ensure the air conditioning system operates efficiently.
  11. Replace old, inefficient air conditioners with new, energy efficient models affixed with Grade 1 Energy Label.

Lighting

  1. Replace traditional light bulbs with compact fluorescent bulbs save as much as 70% to 80% energy per hour.
  2. Take advantage of natural sun light.
  3. Turn off the light that is not in use and affix reminder message near the switch.
  4. Reduce the number of lamps for areas that have natural lighting.
  5. Replace T8, T10 or T12 fluorescent lamps with T5.
  6. Turn off unnecessary lighting in public areas during non-peak hours.
  7. Retrofit fixed output lighting with dimmable lighting using low loss electronic ballast and photocells.
  8. Turn off decorative lights for building or signage after business hours. Avoid unnecessary outdoor lighting.

Lifts and Escalators

  1. Encourage use of the stairs (especially for minimal floor travelling) rather than taking the lift. Affix reminder message near the lifts.
  2. Shut down some of the lifts and escalators during non-peak hours.
  3. Switch off the lighting and ventilation fan inside the lift car when it is in standby/idle mode.
  4. Install auto sensors to activate escalators only when needed for use.

(Source from﹕EPD and EMSD)


Successful Cases from Property Management Category


East Point City ( Kai Shing Management Services Ltd.)

  1. 2% rental revenue reinvests into environmental infrastructure.
  2. Engage the citizens to practice environmental protection while shopping.
  3. Sing energy saving pledge and set the target jointly with the tenant.
  4. Daily Metering record services for the tenants.
  5. Replace with 4 high performance chillers.
  6. Smart lighting control for 24-hour pedestrian area.
  7. Outdoor lighting upgraded to LED.

Hong Kong Pacific Center (Sino Estates Management Ltd.)

  1. Upgrade to 3 sets of water cool chillers.
  2. Dedicated iBMS controller for the chiller systems.
  3. 24 hours remote condensing water quality monitoring system.
  4. Register for the CLP Meter on line service to improve forecast accuracy.
  5. Solar panel installed at the roof top.
  6. Auto sensor to control public area lighting.

Imperial Cullinan (Hong Yip Service Company Ltd)

  1. Energy saving Signal (Green/Yellow/Red) according to the daily weather forecast.
  2. Insulation sheet cover for the heated swimming pool during winter nights.
  3. De-tubing of extra lighting appliances with kind explanation sticker.
  4. Auto sensor to control public area lighting.
  5. Auto sensor to switch off lighting in garbage collection room.
  6. Club kitchen upgraded to using electricity.

Connaught Rd W 118 (DTZ Debenham Tie Leung Prop Mgmt Ltd.)

  1. Upgraded to modern water cool chiller with inverter technology.
  2. Dedicated BMS controller for the new chiller system.
  3. Offer free half-yearly cleaning services to the tenant’s air handler.
  4. LED lighting for public space.

China United Centre (Prosperity Land Estate Mgmt Ltd)

  1. Oil free air cool chiller.
  2. Upgrade the PAU with summer/ winter operating mode.
  3. Upgrade the air duct installation material.
  4. T5 upgrade for public lighting.

Mirama Tower & Shopping Cente

  1. Combined operation of water cool chillers with modern oil free air cool chiller.
  2. Integrate the 2 installed chiller plants to a common network to allow optimization control.
  3. Outdoor lighting and signage all upgraded to LED technology.
  4. Register with CLP Meter-On-Line Service.
  5. Establish green team to promote energy efficiency.
  6. Provide EMSD guide line in decoration planning for large tenants.



Successful Cases


The company successful cases that we are sharing with you this year all have something in common, that is, all energy saving measures are simple, easy to understand and easy to practice. Property management companies that achieved substantial energy saving results varied in size and age of buildings. Despite their energy saving methods differ from each other but all proven to be very effective.


We hope you can find some interesting tips that are applicable to your own home or work place. Successful cases from previous years are also available.

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