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


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


HKT.

  1. The voice network modernization project was started since 2005. In more than 11 exchange buildings, major decommissioning of the old equipment was implemented from 2012 into 2013 and onward upon migration into the Next Generation Network.
  2. The server-base Next Generation Network (NGN) processor power requirement is greatly reduced by advanced IT technology. The NGN core server facilities adopted a more effective cooling technology similar to a green datacenter.
  3. In 9 buildings, existing base-load air-cooled chillers were replaced by high-efficient water-cooled chillers.

Airport Authority Hong Kong

  1. The HK Airport targeted to replace 100,000 pieces of traditional lighting appliances with LED technology. By November 2013, 70,000 pieces have been replaced and the average electricity consumption is reduced from 27W to 15W. A total of 1.3 million kWh of electricity has been saved in one year.
  2. The GBMS installed at the Administration Building will have automatic lighting schedule adapted to different zones.
  3. Combine the chiller systems of 5 buildings into a network to meet the cooling loads more effectively.
  4. The Airport Authority has conducted feasibility research in using wind turbines and solar energy. For example, the facade of a currently under-construction building has incorporated the use of solar panels in its design stage.

The Hong Kong Jockey Club

  1. 1. Upgraded the Shatin horse dormitory from air cooled to water cooled air conditioning system. The high performance air conditioning system installed in Happy Valley is put in full operation during 2013.
  2. Changed the lighting installation of Shatin Administration building from T8 to T5. The facilities at Happy Valley are gradually upgraded to LED technology.
  3. Adjusted the CO2 control value to minimize the un-necessary air exchanges which can reduce the cooling load requirement. The air-conditioning system will be switched to Fan Mode when the outside temperature is lower than 18oC
  4. Joined the Green Office Award Label Scheme. Provided energy saving tips to all employees.

Hop Hing Oil Factory Ltd.

  1. The engineer has obtained more data about the quality of the stock-feed oil and therefore able to fine tune the oil filtration process which resulted in a substantial saving in electricity.
  2. Energy conservation is a high priority from the top management and the electricity saving result is published monthly to encourage staff’s active participation.
  3. Installed motion sensor in those warehouses to cut off lighting when it is not in use. Staff members are reminded to switch off the air-conditioning system and lighting when leaving the conference room or during lunch break. A timer is installed to the water dispensing machine to avoid unnecessary electricity usage after office hour.
  4. Changed the malfunctioned T8 light tube to T5.

JPMorgan Chase Bank, National Association

  1. SmartPrint – staff members have to log-on the printer and can always make last minute changes to printing requirements . Both paper and electricity usage greatly reduced by 20%.
  2. Accelerated the HVAC systems upgrade from air cool to water cool chiller. VSD modification to the computer Room Air Conditioning Unit has reduced 50% power consumption.
  3. Organized portable energy monitors to log electricity usage for participating departments to increase their awareness on energy usage in their daily operation.
  4. Extensive use of cloud computing - typical power consumption per PC terminal is reduced from 400W to 20W.
  5. Used the latest lighting appliances and control technology to reduce lighting power consumption by 30%.

HK Broadband Network Limited

  1. Rearranged the server room. Some old servers are put off line or being replaced with a more energy efficient model.
  2. Upgraded the air-cooled chiller to the water-cooled system.
  3. Organized education programmes on environmental protection and green tips with staff. Dedicated staff to monitor the indoor temperature and adjusted the setting accordingly.

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.

  1. Adopted a hybrid chiller system for cooling in malls. A water mist system is installed to the existing air cooled chiller to improve its heat exchange efficiency. Such systems have been used in GYP, APM, Greenfield Garden (翠怡花園) & Tai Po Mega Mall (大埔超級城).
  2. All new HVAC installation will use water cooled chiller systems except those sites that has site constrains on installation.
  3. More intelligent BMS controls to cut down the number of standby chillers / pumps whilst maintained the same level of reliability for critical applications. This intelligent networking results in 6-7% electricity savings.
  4. 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.
  5. Successfully engaged the owner' corporation of several estates to take on performance based contracts in upgrading the public area lighting.
  6. The architectural design will use more natural lighting in the new building design.

Hong Yip Service Company Ltd.


As an illustrating example, the following measures have been applied in Mikiki shopping mall.
  1. Step from a hardware upgrade methodology towards an energy management centered principle. Mikiki is the first Hong Yip managed mall that is accredited with ISO50001.
  2. After head office has set the energy saving target, Mikiki forms an energy audit committee to review its own energy baseline, and established a finer target and the action plans for different areas within the facility. Management will periodically review the performances from each area and provides recommendation.
  3. For areas installed with old T8 lighting tube, they are replaced by T5 or other more efficient lighting appliance.
  4. Informed the tenants on possible energy saving measures before they move in.
  5. New buildings will incorporate more environmental design, such as using more natural lighting. The mall management will organize periodic programmes on energy saving to their tenant.

Sino Estates Management Limited

  1. Chillers are upgraded to water cooled system. Some heat exchangers are equipped with a cleansing system to improve the heat exchange efficiency.
  2. Set the indoor room temperature to 25.5oC
  3. T8 light tubes are replaced with T5 which is 20% more efficient. Some areas are upgraded with LED lighting which saves 30%-40% of electricity.
  4. Informed the tenants on possible energy saving measures before they move in.
  5. Participated in the CLP Meter online progamme which can forecast the cooling load requirement in the coming 3-5 days more accurately.
  6. Installed water on/off sensor, which is powered by the ambient light, in the water closet to reduce water wastage. Motion sensors are installed in staff rooms.
  7. Motion sensors are installed in the staircases which will dim the light by 30% when no person is detected.
  8. Dimming controls are installed in car parks that achieve 30% electricity reduction.
  9. Some pathways and doors will install solar film to reduce the heat load.
  10. According to the weather condition, administration staff will shut down some of the main lobby lighting.

DTZ DEBENHAM TIE LEUNG PROPERTY MANAGEMENT LIMITED - Camelpaint Centre

  1. The chiller system is upgraded to a high performance water cooled system and the old air cooled system is used for backup only.
  2. A more accurate control on the supply timing of the air conditioning system which reduces its daily operation time by 1 hour.

Prosperity Land Estate Management Limited - China United Centre

  1. Four air cooled and 1 water cooled chillers are installed. The more efficient water cooled chiller is always the first one to be in operation.
  2. A more accurate control on the supply timing of the air condition system which can reduce its daily operation time by 2 hours. According to the weather condition of the day, the chiller supply temperature can be finely adjusted from 7oC to 7.5oC or 8oC in the summer time, and to 9oC during the winter.
  3. Replaced the old insulation in the air duct system.
  4. Replaced and regularly cleaned the air conditioning filter; and reduced the number of air conditioner in operation during the night time.
  5. Changed to use T5 lighting tubes.
  6. New measures under considerations include using LED light and upgrade of the glass façade.

Main Shine Development Limited - Wing Hang Insurance Building

  1. Upgraded the 2 air cooled chillers to water cooled system. Most of the time only 1 chiller is sufficient to meet the cooling demand.
  2. A more accurate control on the supply timing of the air condition system. Adjusted the chiller water supply temperature smartly, especially during the winter.


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.

2013   2012   2011   2010   2009   2008