ENERGY MANAGEMENT
systems and equipment, and analysis of other significant energy consumption drivers. The Survey involved 120 existing government hospitals and 28 hospitals responded fully. Multiple indicators from the survey data, which are assumed to be major influences, were selected for sensitivity analysis to its Annual Energy Consumption (AEC). Problems exist with multi-collinearity in some model parameters which causes large uncertainty bounds in regression coefficient. Nevertheless, the suggested final model could explain 85% of the AEC with a 90% confidence interval in its prediction, showing the highest AEC correlation to total number of assets, numbers of beds, number of pumps and fans, gross floor area as well as mechanically ventilated area.3
building process, relevance of other related factors – such as building construction, climate, occupancy pattern and infiltration not being taken into consideration – might also be crucial in further explaining annual energy consumption. In this case, more demanding analysis, with larger samples and inclusion of other non-parametric variables, should be included to statistically further explain the variability of energy consumption in a hospital building. The measured average Energy
Utilization Index (EEUI) based on GFA is 172 kWh/m2
/yr, calculated from the 28
hospitals. This value reflects a better Malaysian hospital energy intensity, and is significantly lower in comparison to the available standard value of a typical fully air-conditioned office building in Malaysia (220-250 kWh/m2
/yr.1 . The results here
should reflect a better level of expected energy efficiency standard to be achieved in new hospital design. It also suggests a specific energy indicator for Malaysian hospitals, with a lower set of EEUI necessary for future energy efficient hospital design. It is important to note that most typical office buildings in Malaysia are fully treated with mechanical cooling and ventilation, whereas, hospital buildings are designed and operated with only selected areas being mechanically cooled. They also have large naturally ventilated general building spaces and some patient wards use natural ventilation and oscillating fans for a cooling effect on occupants. This explains the lower average EEUI when its energy consumption is normalised to gross floor area. The apportionment of energy observed
in Figures 2 and 3 shows the significant contribution of space cooling system (chillers and environmental control system combined) in hospital building energy consumption. On average, the percentage of energy use under space cooling system is estimated to be about 48%. Other than
22
n Cooling n Lighting n Others 41% 48%
300 250 200 150
11% In the model
Figure 2: All hospitals end-use energy breakdown.
the chillers, environmental control systems and lighting systems, a large portion of energy consumption comes from a vareity of other systems and equipment that exist in the hospitals. These include medical equipment, calorifiers, computers, electric fans, pumps and many more items that contribute a large portion of a hospital’s annual electrical energy consumption. All hospitals estimated an average energy breakdown of 48% for cooling, 11% for lighting and 42% for others. The chillers, as a single energy consuming entity, contribute the most with an average of between 23% and 28% of total consumption. The results suggest that hospitals in Malaysia have a large gross floor area, but on average, only about 69% of its building area is treated with air-conditioning, making its total EEUI (when normalised to gross floor area), much smaller.
100 50 0
Hospital Office building
Figure 3: Comparison of hospital energy breakdown and office building (MECM).
Representative benchmarking or
target consumption as shown in Table 1 was developed to have set values for Typical and Good Practice, based on their EEUI calculated mean values and their lower percentiles respectively. This is a simple but practical framework to help individual hospital understand their energy usage level and identify the possibility of energy saving measures. For comparison purposes, energy
usage of a 990-bed large referral hospital with gross floor area of 65221 m2 – about 72% mechanically cooled – are compared to representative benchmark values of Typical and Good Practice target in Table 1. This hospital registered an annual EEUI of 225 kWh/m2
, which is
quite high when compared to the representative value. From this information alone it can be seen that the hospital facility management need to
Table 1: Representative benchmarks (EEUI) for Malaysian hospitals. EEUI (in kWh/m2
Component Chillers
Environment control system Lighting system Others
Overall Hospital Electrical Energy Benchmarks
Typical 45 37 19 71
172 /yr)
Good Practice 26 13 11
44 94
Table 2: Breakdown of annual energy consumption for base-case building model. Use type
Chiller system Lighting
Equipment Fan
Pump Heat rejection
Total annual electrical energy consumption Electrical Energy Use Index
Total design cooling load requirement
Units kWh kWh kWh
kWh kWh kWh
kWh
kWh/m2 kWh
/yr
Simulation values 7,321,991
3,949,860 4,114,463
1,735,641 1,389,008 433,877
18,944,841 253
10,986 IFHE DIGEST 2017
% of Total 39 21
22 9 7 2
EEUI in kWh/m2
/yr
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80
