Prescribing steam in the 21st century
Angelo Giambrone, 13/09/2019
Steam continues to play an important role in serving the requirements of modern healthcare facilities. Angelo Giambrone, Business Development Manager at Spirax Sarco UK, discusses the influence of this versatile medium on our day-to-day living and why the healthcare sector should continue to embrace steam as an integral component of a 21st Century hospital.
The word steam has the power to conjure imagery of engines moving along a Victorian railway line and of our beloved Brunel standing beside his latest feat of engineering. The reality today however is that steam in our modern world continues to satisfy the exacting demands of a vast array of industries right across the globe and whose influence is seen every day all around us; from the food and drinks we consume, to the clothes we wear, the cars we drive and the medicines that help improve the lives of many. The likelihood is that something currently on you or around you at this very moment will have used steam at some stage along its supply line.
Steam’s use in the healthcare sector is also extensive. Hospitals have made use of it for decades, as its versatility makes it very well suited to the distribution of large quantities of energy for heating, domestic hot water, sterilisation services, and for laundries. We have also seen it being used for humidification and for cooking. Yes, it has been around a while, but its longevity is not without good reason. It is testament to its ability in providing critical, simple and effective energy distribution to healthcare facilities. Its qualities stand it in good stead as we move through the 21stCentury.
Site services in pursuit of modernisation
Hospital steam systems may have been providing dutiful service for a great number of years, but the passage of time isn’t without its effects. An ageing infrastructure can have a detrimental impact on the views, perceptions and personal preferences of those needing to work and manage such systems. It is in these cases that we sometimes see alternatives to steam being considered and complete infrastructure changes muted – generally at high cost and with significant disruption. Comparing a new alternative medium against an existing, tired installation in need of modernisation would not address the whole picture.
With regards to suitability, a question to ask is what medium can meet the demands of the hospital, the hot water needs, the sterilisation services, the laundry services etc., not only for the site today, but importantly for the potential needs of the site tomorrow? What can the chosen medium bring to the table? Quite simply, no other single medium can offer the versatility of steam and the many unique advantages it can bring, which is why so many of our hospitals have been built with steam running through their veins.
We should carefully consider modernisation, optimisation and suitability. There is significant focus within the industry today on ‘demand reduction’ and existing steam systems often have many opportunities to achieve these reductions. The issue of where we can deliver these improvements is something we will discuss later.
Over some years now, we have seen hospitals debate whether to have in-house sterile services, or to outsource. The same debate applies to in-house or outsourced laundry services. Whether you currently have these services within the hospital grounds or not, the ever-growing challenges on our roads (transportation, congestion, fuel costs etc.) and managing logistics, supply and quality, means that having the flexibility in your central energy centre to meet the demands of the site today and in the future becomes a very real consideration when investing in your utilities. Steam can help deliver this and future-proof the site for what it may need to provide in the years to come, as the business landscape changes. In fact, just before writing this article I was asked by a hospital to advise on their idea to build a laundry on site; a task made far easier by the fact they already have steam on site.
Consolidating all your thermal requirement at your energy centre brings another benefit:
Boosting efficiency, flexibility and carbon reduction
Centralising and consolidating your thermal source also maximises the output of any Combined Heat and Power (CHP) plant you may be considering; delivering more electrical power whilst meeting the thermal demands of the site. Cast your mind back to 2008, when the Climate Change Act came into play. It set a target to reduce CO2 emissions in the healthcare sector by 80% by 2050. It has been highlighted within the 2016 Carter Report and by the NHS’ own Sustainable Development Unit, that CHP can provide an excellent way of reducing carbon emissions. These systems can be integrated into new or existing steam systems, allowing the carbon reductions to be obtained, whilst maintaining the benefits of using steam on site.
But what fuel will be used in the hospital of tomorrow? With the ever-changing face of energy provision, not only in the UK but globally, the future could well bring about change to our primary energy sources. The centralisation of boiler plant helps facilitate these changes, adapting to the fuel change at one point, whilst that excellent energy-carrying capacity of steam can still be utilised, serving all the significant users around the site, or even off site.
So if centralisation helps future-proof against changes in fuel supplies, how does this high steam energy get transferred to the various areas of the site?
The reduction of an item’s electrical energy consumption is very topical. All around there are ideas to reduce electrical energy consumption, from LED lighting to variable speed drives on pumps. At a time when we seek this reduction, it is important to know that with steam we have a medium capable of transferring megawatts of energy, yet it does not require pumping to get from A to B. It travels from areas of high pressure to low pressure under its own steam, if you excuse the pun.
When you have a centralised water system, it generally requires a series of pumps in order to transfer energy around the healthcare facility. Many will be circulating large volumes of water all year round, with their associated electrical cost which can run into hundreds of thousands of pounds over the life of the system. Indeed, steam will require a condensate return pump, but the volumes moved are a fraction compared to a water system due to the vastly greater energy content of steam compared to water – typically 26 times greater in fact (kg per kg) when compared to a 60-80oC water system, 47 times greater when compared to a traditional 71-82oC water system. When really delving into what steam offers, it is easy to see why it is often the medium of choice.
Coming clean
The regulatory requirements placed on hospitals and healthcare facilities have been designed to continuously improve patient safety and clinical effectiveness. The guidance issued by the Department of Health makes it clear that steam continues to be a valuable asset. Clean steam, produced from a chemical-free clean steam generator addresses the risk of contamination and ensures consistent control of critical steam quality attributes such as superheat and non-condensable gases. According to Decontamination of Surgical Instruments HTM 0101 (1.3), sterilisation inside a healthcare facility can be undertaken using high-temperature steam and it maintains that “because of its superior qualities, high-temperature steam should be used as the preferred sterilant".
While steam continues to be the preferred sterilisation solution for the Department of Health, demonstrating both its critical function in protecting patient lives and in maintaining the highest hygiene standards possible, the role of the hospital’s plant steam distribution system in providing the required thermal energy remains high on the agenda. In fact, the HTM 07-02 Making Energy work in healthcare refers to steam as the preferred primary medium for sterilisers, rinse water heating, reverse osmosis water heating and drying.
Delivering Improvements
From the boilerhouse, through the distribution system and into the plantrooms, there are many areas of consideration for the site looking to modernise and improve a steam system. It may seem obvious, but ensuring that lagging is of a good standard is crucial in maximising system efficiency. This is of course relevant to any medium, but an ageing installation will often offer significant opportunity for improvement.
Boiler water feedtanks have traditionally been atmospheric units in the UK. More commonplace in Europe is the Pressurised Deaerator, which operates just above atmospheric pressure, thus driving off oxygen from the feedwater. This helps to improve the quality of the steam and condensate, therefore increasing the longevity of the steam infrastructure. Its low-pressure operation provides an effective way of capturing surplus energy that may be found in the boilerhouse, boosting overall system efficiency.
Boilers have two key areas where energy can be recovered; one being to capture the thermal energy in boiler flue gases using an economiser, which is typically used to pre-heat the feedwater going in to the boiler and the other being boiler blowdown, where hot water is discharged from a boiler to maintain the internal dissolved solids level at an optimum. Fuel savings from each can typically be between 3 and 5%.
In the distribution system, steam traps are integral in the safe and effective operation of a steam system. Whatever type of trap is employed, there will be an aspect of maintenance required to maintain maximum system efficiency, whether it be cleaning a strainer or changing a trap. Traditionally made of a number of separate components (valves, strainers, etc.), the latest generation of one-piece trapping solutions have reduced potential leak paths from a typical 18 to just 3, vastly reducing maintenance and associated costs. It is important to have the ability to access any trapping item quickly and effectively. The STS17.2 steam trap has transformed the way this is achieved and has found favour across many industries with its integral componentry, saving time and money by helping sites to keep steam traps running at maximum efficiency.
In plantrooms, the compact EasiHeatTM steam-to-water plate heat exchangers offer an energy-efficient alternative to the traditional shell and tubes in the generation of hot water. Modern plate heat exchangers are designed to operate at optimum conditions for efficiency and also have the added-value benefit of reduced operational costs, eliminating the ongoing strip-downs that calorifiers require for insurance purposes.
Space is increasingly at a premium in hospitals and there are demands set for how the space available is used. When considering a traditional plantroom, there may have been a number of large domestic hot water (DHW) calorifiers occupying a considerable footprint. This can usually be satisfied using the DHW EasiHeatTM that delivers instantaneous hot water from a much smaller footprint. Not only does this provide benefits in terms of reduced losses (no radiated losses from stored water volumes) but it also helps to minimise the legionella risk by the removal of the stored water volume.
Condensate recovery provides substantial benefits to those who manage the finances of their healthcare facility. Condensate is ideal for use as boiler feedwater as it has both heat content and is of a quality to minimise boiler blowdown, thus saving energy. Returning condensate will not only minimise raw water use, but also reduce the amount of boiler treatment chemicals consumed, again with an associated financial saving.
Where next?
A hospital’s primary function is to provide care to patients, this includes keeping them safe from infection and comfortable by providing a warm, clean environment. Steam has always played a key role in helping to deliver these services. Carbon Reduction measures and saving energy is driving the Healthcare sector to look very closely at what it can do with its utilities – there is much that can be done with our incredibly effective steam systems to ensure they improve too.
The picture of our hospitals and how they operate in the future may well change, but the versatility and adaptability of steam can help to ensure that our hospitals can continue to deliver, whatever the 21st Century brings.
For more information on how Spirax Sarco can assist your healthcare facility, click below:
Best Practice Guide to achieving reliable and consistent high quality steam
Your Guide to achieving reliable high-quality sterilisation through the provision of dry clean steam.