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. Small $20,000 renovation cost results in monthly electricity saving in excess of $40,000.
  2. Electricity audit on each floor to establish base lines.
  3. Remove excessive installed lighting appliances ( over 25%!).
  4. Add window film or curtain at hotspots.
  5. Motion sensors are installed at the classrooms. All switches have energy efficiency labels as reminder.
  6. Use available energy saving contest in the community to promote the energy saving concept.

HK IVE (Tsing Yi)

  1. A dedicated committee is formed to promote environment conservation.
  2. Energy efficiency measures are taught in environmental courses.
  3. Change to water cool air conditioning system. ( over 25%!).
  4. Gradually change to T5/ LED lighting.
  5. Motion detectors are installed in toilets.
  6. Detail zoning and labels on the A/C and lighting on-off switches.

HK IVE (Tuen Mun) & Youth College

  1. Change to water cool air conditioning system.
  2. Gradually change to T5/ LED lighting.
  3. More usage of natural lighting.( over 25%!).
  4. Windows films or motion detectors are installed in the classrooms.
  5. Detail zoning and labels on the A/C and lighting on-off switches.
  6. A dedicated committee is formed to promote environment conservation.

Lok Sin Tong Leung Kau Kui College

  1. Support from the principal, teachers and students are essential to achieve good saving result.
  2. Green ambassadors are nominated from each class, and forming green committee.
  3. Green committee will check the classrooms during the break.
  4. Students are asked to sit closer together for classes with less students..
  5. Monthly report the energy saving record in the school campus.

Shun Tak Fraternal Association Lee Shau Kee College

  1. Engage the student’s awareness and participation when the school terms starts in September.
  2. Maintain student motivation.
  3. Green ambassadors are nominated from each class, and forming green committee.
  4. Green committee will check the classrooms during the break.
  5. The school has changed all lighting to LED.


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


Hospital Authority (Headquarter Building)

  1. Upgrade the aged chiller unit.
  2. Upgrade to T5 or LED lighting.
  3. Staff notice to turn off lighting and air conditioning system during lunch hours and after office hour.
  4. Shared use of conference room during OT or use a small portable A/C unit.
  5. Periodic experience sharing with fun sessions to promote environment protection .

HKT Limited

  1. Ongoing upgrade of the Voice Network Equipment.
  2. The retiring switching equipment is upgraded to the NGN processor which can reduce electricity consumption by 70%.
  3. Gradually upgrade with water cooled chiller plant.

The Hong Kong Jockey Club


Happy Valley Racing Facility
  1. Ongoing upgrade of the Voice Network Equipment.
  2. The retiring switching equipment is upgraded to the NGN processor which can reduce electricity consumption by 70%.
  3. Gradually upgrade with water cooled chiller plant.
City Bet Center
  1. The Jockey Club signage will be turned off during the daytime
  2. Indoor spot light and TV are upgraded to more efficient models

The Royal Bank of Scotland plc

  1. The premise is upgraded with LED lighting.
  2. Rezoning in the lighting plan to avoid over lighting.
  3. Provision of timer for turn off kitchen equipment.
  4. Addition of ventilation fan and rearranging the servers in the data center to avoid hot spots, therefore minimize the cooling demand
  5. The security guard will adjust the A/C and Lighting system during the night shift

Tsit Wing Coffee Co. Ltd

  1. Better planning on the lighting and air conditioning zones during recent renovation.
  2. Centralized access of the warehouse to minimize cold air leakage.
  3. Keep electricity usage record at department level, with regular review.
  4. Kind reminder to new employee who might forget to turn off the lighting.
  5. Even the most reluctant employees will gradually develop the right energy saving habit.

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


Kai Shing Management Services Ltd.

Air Conditioning System
  1. Add water spray system to existing air cool chiller system.
  2. Better management of the chiller system to maintain a higher load with less numbers of chillers in operation.
  3. Use water cool chiller systems whenever possible.
Energy Efficiency Programmes
  1. Gradually upgraded the public lighting from T8 to T5, and to LED lightings for applications that fit. Use occupancy sensor to smartly dim down the lights along staircases and corridors, and utilized the photo sensor to adjust or on/off the external facade lightings.
  2. Successfully engaged the owner' corporation of several estates to take on performance based contracts in upgrading the public area lighting.
  3. The architectural design will use more natural lighting in the new building design.

Hong Yip Service Company Ltd., using Imperial Cullinan as example:

  1. Window films to block the heat intake from the sun.
  2. Better covering of the heated swimming pool during the winter time.
  3. Remove excess lighting and switch to LED lighting.
  4. Timer control on the public lighting and ventilation system.
  5. Upgrade the elevators with VVVF technology.
  6. Sign the deed to maintain indoor temperature at 24-26℃.

The Great Eagle Prop. Mgmt Co. Ltd. (Citibank Plaza)

  1. A Green Group is formed with tenant participation.
  2. Upgrade with a water cool chiller which reduce electricity consumption by 26%.
  3. Lighting are all upgrade to T5 models and LED will be used whenever practical.
  4. Encourage the tenant to join the Energy Saving Deed promoted by EMSD.
  5. Control the lighting system on/off schedule according to the weather condition of the day.
  6. Turn off some elevators during non-peak hours.

Protech Property Management Ltd. - Lockhart Centre(Citibank Plaza)

  1. Switch to multiple units of standalone air conditioning units to add control flexibility.
  2. Upgrade public lighting with LED lighting.
  3. Upgrade the elevators’ motor performance.
  4. Turn off 1 elevator after 8pm.
  5. Regular meeting with the Owner’s Corporate to discuss saving opportunity, like installation of window film.

Hon Hing Enterprises Limited – Marvel Industrial Building

  1. A Green Group is formed with tenant participation.
  2. Upgrade with a water cool chiller which reduce electricity consumption by 26%.
  3. Lighting are all upgrade to T5 models and LED will be used whenever practical.
  4. Encourage the tenant to join the Energy Saving Deed promoted by EMSD.
  5. Control the lighting system on/off schedule according to the weather condition of the day.
  6. Turn off some elevators during non-peak hours.

Urban Property Management Limited – Tin Yau Court

  1. Upgrade with 4899 sets of LED lighting.
  2. Turn off some public lighting during daytime.
  3. Adjust the monthly lighting on/off schedule, following the advice from Hong Kong Observatory.
  4. Turn off some elevators during midnight.
  5. Adjust the water pumps to minimize the turn-on cycle.
  6. Management office uses Energy Label Grade A A/C.


Energy Saving Tips for Household


Air Conditioning

  1. Electric fans consume only one-tenth of the electricity required as compared to an air-conditioner, use electric fans instead of air-conditioner if possible.
  2. Ensure doors and windows are closed properly to prevent leakage of cooled air.
  3. Clean or replace filters in air-conditioners regularly to improve energy efficiency. Such measure could save as much as 30% of electricity consumption.
  4. Maintain the air-conditioned temperature to 25.5℃ - 26℃.
  5. By adjusting the air-conditioner temperature upward by 1℃ , it could help to reduce about 3% of electricity consumption.

Lighting

  1. Replace traditional light bulbs with compact fluorescent bulbs could save as much as 70% to 80% energy per hour.
  2. Take advantage of natural sun light.
  3. Adjust the lights to appropriate intensity as required.

Computer

  1. Save up to 90% of electricity consumption by setting the computer to sleep mode after idling for 20 minutes, and turning off the monitor when not in use.
  2. Turn off the master switch for printers or other peripherals if not in use.

Electric Appliances

  1. Electric appliances consume 10% more energy with stand-by mode. They should be shut down completely if not in use.
  2. Wait until you have a full load of clothes before using the washing machine. Hang clothes to dry naturally instead of using a dryer.
  3. When using washing machines, use cold water instead of hot water.
  4. Defrost freezers regularly. The accumulation of ice will increase energy consumption.
  5. Repair seal and hinge along the door of the refrigerator when broken, leaks increase electricity consumption by 5% to 15%.
  6. Wait until the food cooled down to room temperature before putting it in the refrigerator.
  7. Placing your refrigerator near heat source may affect its proper functions and energy efficiency.
  8. Prevent the refrigerator door from opening for a long time or frequently. The interior temperature will increase after the refrigerator door has been opened. Extra energy consumption is required in order to maintain the temperature.
  9. Select energy efficient appliances affixed with Grade 1 Energy Label. For refrigerators, as an example, save up to 15% to 30% of energy consumption.

(Source from﹕EPD and EMSD)


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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