HOSPITAL ENERGY SYSTEMS
directly by Sterile Services Departments. The electricity is split as we would expect – lighting, general power, equipment, and HVAC equipment.
HVAC systems If we focus in on the energy usage by HVAC systems, this typically accounts for a whopping 65% of the total energy consumed by a hospital. This isn’t too surprising when considering the amount of ventilation and associated treatment of this air, but is still a very large proportion. Well, what happens when this natural gas supply gets removed? For new, small-to-medium-sized, one-
A healthcare facility’s prime goal is to improve the health and well-being of the occupants; the engineering services play a fundamental part.
in Victoria and New South Wales, the grid can in no way be classified as ‘green’. In fact, from an energy perspective, a kWh of gas is about four times cleaner
than a kWh of electricity in terms of CO2 equivalent in Victoria. We’re heading in the right direction, and things are improving, but not quickly enough. In 2021, 24% of Australia’s electrical generation was renewable, so it’s not good enough for companies and government entities to say: “We will solve our fossil fuel issues by buying ‘green power’”, because there isn’t enough to go round. If everyone signed up, 74% of the signatories will be either disappointed or misled by their power providers.
Electrification and clinical care So, what does electrification of buildings have to do with clinical care? The prime objective of a healthcare facility is to improve the health and well-being of the occupants; the engineering services within a healthcare facility are a fundamental part of this process. Patients and staff have a right to expect that engineering systems and equipment will be designed, installed, operated, and maintained, to standards that will enable them to function efficiently, reliably, and safely. The unique nature of healthcare premises – and the dependency of patients on the provision of effective and efficient engineering services – requires that engineering systems must be resilient, to maintain the continuity of health services, and ensure the ongoing safety of patients, visitors, and staff. Multiple fuel sources give these facilities clinical resilience.
Not low energy-users Hospitals are not low energy users. In fact, the average energy density of a hospital in Victoria is 1.4 GJ/m2
per year. To put 22 Health Estate Journal February 2023 ‘‘ System
DHW (Boilers / Steam) Heating (Boilers / Steam) Sterilisation equipment Catering equipment
Equivalent CoP
We should not be trying to artificially reduce energy consumption to the detriment of patient care
that in perspective, a five-star premium- grade commercial office building in Melbourne would be around 0.35 GJ/m2
.
Now, this isn’t to say that we should not be trying to reduce energy consumption, and indeed there is no excuse for poor or wasteful design. However, we should not be trying to artificially reduce energy consumption to the detriment of patient care. So, where does all the energy go in a modern acute hospital (see Figures 1 and 2)? The energy split is in fact is roughly the same across all hospitals worldwide – and is close to a 50/50 split between gas and electricity. If we look at how the gas is consumed, 74% is burned heating water (domestic hot water and heating) and steam-generation equipment, 20% is used directly for catering, and 6% is used
off, healthcare buildings, with a mandate in a brief, it is relatively simple to design and construct an all-electric facility. Some minor challenges within the BCA (Building Code of Australia) that limit the amount of electric reheat allowed within buildings, and the size of electric water heaters (NCC Vol 1 J5.9) exist; however, these limitations are simply regulation, so can be changed. There are no engineering showstoppers; everything is achievable.
Options for de-gassing an acute facility What are the options for de-gassing an acute facility in the Central Business District (CBD), with minimal risk to patient care or clinical service delivery? The biggest challenge facing new large facilities and existing hospitals is their energy density. When compared with commercial offices, a hospital can require three to four times the energy per square metre. This makes the opportunities for on-site renewable generation extremely limited. This problem is compounded by the fact that most of our hospitals in Australia are landlocked, and the roofs are heavily loaded with engineering services necessary to support the clinical functions – and even helipads for the major facilities. Legacy issues must be considered
– very few hospitals are built from a greenfield site. They are often part of wider campuses, and the larger hospital campuses are based around a central
Portion of Gas demand Equivalent demand (%)
22% 52% 6%
20%
100% 2.0
Previous electrical demand 116.9 TJ New total electrical demand 162.8 TJ Resultant increase in usage
39% Table 1: The impact on electrical energy consumed by swapping out gas for electricity.
(TJ) 19
45 7
21 92.6
4 1 1
– Equiv. electrical
system (CoP) demand (TJ) 3
6.4 11.3 7.1
21.2 46.0
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
