implementation of energy saving measures in existing buildings€¦ · implementation of energy...

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%.


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


• 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)


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


• 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


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.


Tubes before cleaning

Tube after 300 hours operation with ATCS

Tubes just after manual cleaning


• 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%


• 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


• 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


• 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

Temp. of HW ~ 53oCTemp. of CW ~ 23oC


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

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