Implementation of Energy Saving measures in Existing Buildings 5 September 2009 Building Surveyors Conference on “Building a Green and Sustainable Future”
Implementation of Energy Saving measures in Existing Buildings
5 September 2009
Building Surveyors Conference on“Building a Green and Sustainable Future”
Energy Efficient / Environmental Friendly Products
During the past years, we have been exploring new technology and new products for our customers.
The following list shows some of these items which have been used by our customers.
Charging BatteryCremation FurnaceElectric CarsElectric ForkliftOven TunnelArc Furnace / Smelter
IndustrialHigh efficiency motorHeat exchangerInfra-red heating and DryingWaste IncineratorRTGC for Ports
Hot Water and SteamElectric water heaterAir link water heaterCompact sized heat pump water heaterHigh efficiency heat pump (COP>5 , 60oCoutput)High temperature heat pump (COP>3 , 85oC output)High voltage steam boiler
Cooking Chinese steamerSteam cabinetAutomatic rice cookerFryerMultipurpose ovenInduction pot stoveInduction wokBBO sets
IAQFresh air unitHigh efficiency filterUltra Violent SterilizerTiO2 Filter
LightingEnergy efficiency fluorescent tubeCompact fluorescent lampElectronic ballastLeon Lighting
ElectricalVariable speed driveHarmonic filterCapacitorVoltage optimizer
Air ConditioningWater cooled chillerCooling towerHeat pump desiccant dehumidifierHigh capacity dehumidifiers Mobile AC
Energy Efficient / Environmental Friendly Products
Energy Efficient / Environmental Friendly ProductsThe following slides will show those items which are most welcomed by our customers, namely, they are:
1. Energy Efficient Chiller2. Heat Pump Water Heater3. Energy efficient lightings and Controls4. Induction Cooker / Electric Cooking5. Capacitor Bank6. Solar Hot Water Heating7. Green Roof and Wall
• Properly select heat rejection methods• Design efficient water pumping systems• Focus on chiller part load efficiency• Integrate chiller Controls with Building
BMS
Four design strategies for an efficient chiller plant
Energy Efficient Chillers
Heat extracted from air-conditioned spaces and the work input to the refrigeration machine (chillers) = Heat rejection, a cooling medium needed for the heat rejection• Air – always available
• Fresh water – can be made available economically only if there is a river or lake nearby
• Seawater – available to buildings nearby the harbour
• The cooling medium will directly affect the chiller refrigerant condensing temperature. One Deg. C lower, the chiller COP will be improved by 2-3%.
Energy Efficient Chillers
35oC40 - 41oC41 - 42oC45oC48 - 50oCRefrigerant Condensing Temp
37oC38oC45-47oCCondenser Water Out Temp
32oC33oC40-42oCCondenser Water In Temp
33oC33oCCooling Water Out Temp
28oC28oCCooling Water In Temp
28oCAir WB Temp
33oC33oCAir DB Temp
Direct Seawater Cooled
Evaporative Type Cooling Tower
Indirect Seawater Cooled
Air Cooled
Dry Tower (Air-cooled radiator)
Refrigerant condensing temperatures for different heat rejection methods
Energy Efficient Chillers
• Air-cooled chillers• Design condenser air inlet temperature 35°C (Hong Kong)• COP in the range of 2.6 to 3.0 (inclusive of the condenser fan power)
• Water-cooled chillers• Design condenser water inlet temperature (direct seawater cooled)
27°C (Hong Kong)• COP in the range of 4.0 to 5.0 (inclusive of the seawater pump power
or cooling tower power)
Energy Efficient Chillers
Water-cooled air-conditioning systems (WACS) consume 20 -30% less energy than air-cooled air-conditioning systems (AACS)
• For the other areas cannot use WACS, there still have some ways to improve their air-cooled chiller plant efficiency
- Ensure sufficient condenser air flow
- Avoid condenser air short circuit
- Mitigate condenser fin corrosion problem
Energy Efficient Chillers
• For buildings that can adopt water-cooled air-conditioning system, congratulations, but still have some points to note
- Minimize fouling in the water-cooled condensers
- Automatic condenser tube cleaning system
Energy Efficient Chillers
Cooling waterRefrigerant side
surface of copper tube
Clean surface of copper tube
Refrigerant particle
Foul
Cooling water
Refrigerant particle Refrigerant side
Cooling water Cooling water
Periodically cleaning the condenser tubers
Remove the scale which will degrade the performance of heat transfer and hence the operation efficiency of chillers.
Energy Efficient Chillers
Tubes before cleaning
Tube after 300 hours operation with ATCS
Tubes just after manual cleaning
Energy Efficient Chillers
• Chillers operate at low part load condition may have very low efficiency
• Install small chillers to handle system part load period
• Chillers with VSD drive compressors may have a better part-load performance
• Oil-free chiller…
100% 90% 80% 70% 60% 50% 40% 30%Load %
Efficiency KW/RT
Efficiency change %
0.65 0.647 0.666 0.697 0.749 0.822 0.904 0.973
100% 99.5% 103% 107% 115% 127% 139% 150%
Part-load performance of a typical centrifugal chiller
20%
1.053
162%
Energy Efficient Chillers
• Efficient pumping systems
• Avoid oversized and then “throttled” to produce desired performance
• Keep the fluid velocity down• Keep the temperature differential up• Keep the piping system simple• Use variable flow configuration and controls
Energy Efficient Chillers
• Integrate chiller controls with Building BMS
• Specify am “open” communication protocol (e.g. BacNet)
• Apply Chiller Plant “Optimization” Control Logic
25% 50% 75% 100%0%
25%
50%
75%
100%
Pow
er C
onsu
mpt
ion
Cooling Load
1
2
3
4
No. of ChillerOperating
Energy Efficient Chillers
• More energy efficient than using other fuel source
• COP ~3 with output temperature at 55°C
Chilled Water
Cooled Chilled Water
Heat Pump Hot Water Supply - conventional
• Higher Efficiency (COP > 5) using alternative heat sources e.g. chiller condensing water
High Efficiency Heat Pump
Typical Heat Pump
• New type of refrigerant to produce higher temp. output (up to 85oC)• More tailor made products for different types of applications
Heat Pump Hot Water Supply – new technology
Hot Water Supply / Dehumidification
:Applicationviii.
> 5 at output temp. rise 40oC :COPii.
Design Characteristics
Refrigerant
Heat Source
Max. output temp.Temp. of water source
Heating capacity
Compressor, Refrigerant Flow:vii.
Condensing water:v.
R134a:vi.
~ 60oC:iv.7 to 40oC:iii.
150kW – 2,000kW:i.
• Conventional HPs: using air or chilled water (12 oC ) of chillers as heat source. COP < 2.5 - 3.
• High Efficiency HPs: A new HP design using chiller’s condensing water (20-35oC) or other similar temp. water as heat sources coped by the new design of compressor and refrigerant control, COP>5.
Heat Pump Hot Water Supply – High Efficiency
Why is the Output Temperature Higher ?Technology developed by Qinghua University / Guangzhou Institute of Energy Conservation , using new environmental healthy refrigerants which can sustain higher temperature during compression
Numerous job references on commercial and industrial projects in China, no installations in HK
Heat Pump that can use low grade heat source with temp. ~ 20 to 60oC to generate high grade energy with temp. up to 85oC.
~ 20 to 60oC:Input heatii.
:
::
:
Condensing water / Geothermal heat / Waste heat generated from manufacturing process
Heat Sourceiv.~ 85oCMax. output temp.iii.
Hot water supply / Dehumidification / Industrial process drying
Applicationv.
> 3.5 at output temp. rise 45oC COPi.
Heat Pump Hot Water Supply – High Temp
Compressor compress the refrigerant vapour and directs the hot compressed vapourrefrigerant to the copper tubes around the water storage tank
Cooled liquid refrigerant is passed through the evaporator inside or outside the unit where heat from the surrounding is absorbed into vapour.
Hot water is generated with much higher efficiency resulting from the COP of the heat pump refrigerant cycle
Heating element is incorporated in the water tank to supplement the heating if necessary
Free cooled air produced by the evaporator or sport cooling
Heat Pump Hot Water Supply – Integrated Type
Heat Pump Hot Water Supply – Integrated Type
Temp. of HW ~ 53oCTemp. of CW ~ 23oC
Heat Pump Hot Water Supply – Integrated Type
Energy efficient lightings
Energy efficient lightings - LED
Electromagnetic ballast Electronic ballast
Energy efficient lightings - Ballast
Energy efficient lightings - Controls
Simple Manual Control
Intelligent Digital Control
Induction Cooker
Induction Cooker
• Heats up 30% faster• Saves 45% fuel cost• Energy transfer is instantaneous
and highly controllable• Minimal heat loss - kitchen is
kept cool
Safety
Health
• No naked flame – fire risk minimized• Harmful combustion pollutants, including
CO, NOx & carcinogen PAHs, are eliminated
Environment• Energy efficiency up to 90% - most
efficient cooking technology• Local emission is eliminated
Induction Cooker
• Various models from 1 to 5-zone, from 2 to 3kW / zone, ideal for Chinese Wok cooking
• Sophisticated safety features -ideal for open kitchen
• Modular hobs are available for dual-fuel combination
Induction Cooker – Different Brands
Channels:
Brands: Kitchen Basics
Induction Cooker – Cookwares
Induction Stock Pot Stove
Electric Heated Chinese Steamer Electric Fryer
Multi-purpose oven
Electric Automatic Rice Cooker
Steam Cabinet
Induction Wok
Electric Cookers
Capacitor Bank
Install capacitor to maintain a high power factor
Reduce the demand charge
PF : 0.84 → 0.94
Demand:1000 kVA → 894 kVA
Reduced by 10.6%
Capacitor Bank
Solar Hot Water Heating
Payback or not depends on circuit design and structural support cost!
Green Roof / Wall – many queries from customers
HKBUTaiwan
Singapore
US
HKBU
A HK School
Let’s work harder for the Environment !
THANK YOUTHANK YOU