背景﹕由於香港九成用電係嚟自building, 舊樓好多BS系統效能唔高。
Retro Commissioning 係重新校驗BS系統，一棟樓行得耐既時候，好多時個control system又outdate, 啲sensor又唔準等等，一旦較正咗個building owner即時慳到電有著數；主要係一個systematic process quick fix operational improvements save energy而唔係成件equipment咁換；
而BEEO / BEC 係針對New Building or Major Retrofitting Works, 而且十年要一次Energy Aduit;
*Major Retrofitting Works MRW 定義﹕
- 換BS嘢既面積大過500 m2;
- 換個electrical circuit 大過400A;
- 換AC嘢大過350kW;
- 換lift;
EMSD出咗本Technical Guidelines on Retro-Commissioning, 本嘢有三個主要部份
1. Work Stage: Planning-->Investigation-->Implementation-->On-going
2. Example;
3. Check List;
Stage 1: Drawings manual collection, inspection, develop plan;
Stage 2: Site survey, conduct data logging, monitoring, identify potential measures;
Stage 3: Performing verification, training O&M staff;
Stage 4: Electricity bill, satisfaction of occupants, continuous monitoring;
現在﹕總共有三台Air Cooled Chillers 行VSD，平時30-50% load嗰陣係行兩台。
新方案﹕回顧返個cooling load profile後，會唔會响30-50% load嗰陣同時行三台COP仲好啲？因為用VSD的話响part load condition個綜合COP更高。
結果﹕果然好咗喎。完。
(Source: EMSD)
