Course Hero Logo

Energy efficient schemes (Week 3).pdf - AGENDA : •...

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 1 - 11 out of 47 pages.

AGENDA :Introduction1.Energy Efficiency for HVAC2.Energy Efficiency for Lightings3.Energy Efficiency for Lifts and Escalators4.Energy Efficiency for other Equip/Materials1
SpaceConditioning48%OfficeEquipment22%Other (e.g.Lifts)11%Lighting19%Rough proportion of electricity consumption in acommercial buildingIntroduction2
Energy Efficency Considerationsin BS design :Electronic ballast for luminairesT5 fluorescent luminaires and LED…Photo-sensor control for lightingOccupancy sensor to control lighting & A/C on/offCO2sensor control to limit over-provide of pre-treatedfresh air supplyWater cooled chiller plantsHeat Pump systemsFree cooling for offices in winterBleed-off / Grey water for toilet flushingIntroduction(Cont’d)3
1.HVAC Equipment & Systems®Most 3-phase induction motors for chillers orpumpsshallbe driven viavariable-speed drive(VSD)seed-drive(VSD) fans®Air or water flow is either constant volume orregulated by mechanical means, e.g. airvanes/dampers, water by-pass valve, etc.®Mechanical volume control adds loss in the systemand is energy inefficient.®As power required by fan or pump reducedproportionally to the cube power of the motorspeed (Fan Laws), the application of VSD in volumeflow control is more energy efficient, e.g. 20%speed reduction in motor need 51% of the originalpower.4
Motor Energy Saving with VSD020406080100120020406080100120Speed/Flow %Motor Power %Fan/Pump Cube LawHVAC Equipment & Systems(cont’d)5
®Fresh air (FA) supply in building is normally fed via PAU atconstant air volume based on FA at 10 litres/s /person (seeASHRAE 62.2000)®PAU then pre-treats & coolsthe outdoor air from thedesignedoutdoor temperature of33.5oC to a lower value®Constant FA is a great wastage of energy®Demand control on PAU using CO2sensor & VSD motors cansave energy in the air-conditioned space with variable andintermittent occupancy, such as vacant at lunch time …®CO2content of <1000 ppm is required according to ASHRAEstandardandthe HK IAQGuidance NotesEnergy Efficient HVAC Equipment & Systems(Cont’d)6
Queensway Gov’tOffices - VSD for 3 nos. 37 kWchilled water pumpsExamples on Buildings using VSD for pumps…7
Examples ofusingVSDinChillersShatin Town Hall – 400 TR water-cooled chillerretrofitted with VSD to improve its part-loadperformance8
lEvaporating cooling for air-cooled chillers atTsuen Wan Yeung Uk Road Indoor GamesHall (increased of energy saving by 15% )Another example on using external waterspraying system to improve the COP ofchiller9
l

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 47 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
N/A
Tags
Incandescent light bulb, Fluorescent lamp, Electrical ballast

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture