How Does Saving Energy Affect Legionella Control Measures?
In today’s climate-conscious world, the push toward energy efficiency is stronger than ever, with homes and businesses alike seeking ways to reduce energy consumption and lower carbon footprints. While this shift is essential for environmental and financial reasons, it’s equally important to recognise the unintended consequences that some energy-saving measures may have … particularly in relation to water safety. One often-overlooked risk is the increased potential for Legionella bacteria to thrive in conditions where water temperatures are insufficient to inhibit their growth, posing serious health risks such as Legionnaires’ disease.
This article explores the delicate balance between implementing energy-efficient systems and maintaining effective Legionella control measures. It examines the role of water temperature in bacterial prevention, discusses common energy saving technologies such as heat pumps and solar thermal systems, and highlights best practices in building design and retrofitting. It also emphasises the importance of informed decision-making and regulatory compliance in ensuring that energy-saving initiatives do not come at the expense of public health and safety.
A version of this story about how the implementation of energy savings can affect Legionella control measures first appeared in Legionella Control International’s newsletter. To get it in your inbox, sign up here.
Energy savings versus Legionella control
You don’t need to look far to find plenty of news and insight into energy saving measures – whether that is in the home or in commercial buildings. However, it would be wrong to focus all our efforts on saving energy, especially where the control of Legionella and other waterborne bacteria are concerned. Legionella bacteria, which is responsible for the potentially deadly condition Legionnaires’ disease, thrives in water at temperatures of between 20 and 45 degrees Celsius. If energy saving measures cannot achieve a high enough temperature to maintain a safe water supply, this could have far more serious consequences.
Clearly, there is a need for balance between saving energy and making sure any water system being used is safe for those using it. That’s the focus of this article, so let’s find out more.
Energy efficient ways to generate hot water
There are a few potential methods to consider here. Heat pumps have certainly been highlighted in the media, with ground source and air source heat pumps available. However, they’re not ideal given the UK climate.
Solar thermal energy provides another questionable source of energy, given the changing weather in the UK throughout the year. Solar panels are more common at present, although while they do still work when it’s cloudy, they only hit around 10-25% of the output enjoyed when it is sunny.
How can businesses save energy heating water?
Becoming more energy efficient does make sense, but you need to make sure the methods you use do work as you think they will. For example, a water boiler may prove to be more efficient than having kettles, especially in workplaces where they’re going to be used a lot. Since the water boiler should be well insulated, it won’t heat water from a standing start each time. That said, you do need to make sure the water is kept at safe temperatures.
The larger the building, the more likely it is that there will be energy losses occurring somewhere. For example, heat can be lost through pipework that has been inadequately insulated – or not insulated at all. Proper insulation also prevents changes in water temperature that can be caused when hot and cold pipes run next to each other.
Energy efficient building design and future proofing water systems
When a new building is being constructed, whether that is a new home or a new commercial building, it is essential to make sure energy efficient measures are used. However, these should be balanced with common sense.
For example, is it necessary to future proof a building? Let’s consider a new hospital facility. This will obviously include a new hot and cold water system built specifically for that building. Architects and engineers involved in the design process should consider which elements are required from the water system. How many showers, room en-suites, toilets, and sinks will be required? Where will the radiators be positioned, and how many of those will require thermostatic mixing valves (TMVs)?
It is easy to overdo things here, adding more sinks, outlets and larger capacity water storage than you think might be required each day. Could there be a room that might be used for patients, but no one is sure whether that will eventually occur? Using this as an example, we can see that basing a hot and cold-water system on what might happen or be required in future is not the ideal scenario, especially from a water safety perspective.
For starters, future proofing like this may mean the hot and cold-water system is designed to provide services to this room, yet it is a room that may never be used. Or if it is, this may not happen for months. It seems like a good idea – get the water supplies into that room now, so they’re there and ready for use as and when required.
But supposing they are never required? This leaves you with a sink, taps, and perhaps a shower or other facilities that aren’t needed. It makes the water system unnecessarily bigger and requires someone to regularly flush through the taps and other outlets, to be sure any bacteria in there are flushed away. This takes time and means there is a bigger risk factor for Legionella and other waterborne bacteria to take hold.
Let’s assume this room is built but not serviced by the water system. If it is required in this way in future, it will need to have those services – a sink, taps, and shower, perhaps – added and connected to the mains distribution system. That might seem inconvenient, but in the meantime, not having them in place when they’re not needed saves people resources, energy and the risk of Legionella developing there.
Assessing Legionella risk factors before making energy saving changes
It’s worth noting that Legionella and other water safety risk factors and opportunities for saving energy do not merely occur at the design stage. A commercial building could be in regular use, and smaller decisions may arise that involve potential risk factors and energy usage.
Thus, both factors must be considered before any decisions are made. Let’s look at something seen in many office buildings and other commercial venues – the water cooler. So synonymous is this with office culture that we talk about water cooler moments – discussions had around the water cooler as we catch up on last night’s TV.
There are pros and cons to having a water cooler, as you might guess. They do use energy to run, so unless you’re going to have one in a main area, they could end up using far more energy than you might assume. Moreover, you need to be sure they’re kept at a cold enough temperature to prevent any risk of Legionella growth… or other waterborne bacteria.
Maintaining safe water temperatures – whether hot or cold
We’ve touched on plenty of topics in this article, but if you are using thermal control techniques it all comes down to this – water temperature. It’s essential to make sure that cold water remains below the 20 degrees Celsius danger zone for Legionella growth. Hot water must be well above 45 degrees Celsius as well, otherwise the risk is there too (hot water outlets should reach a minimum of 50 degrees Celsius, 55 in healthcare).
That’s why heat pumps and solar water heating may sound good for energy efficient purposes, but on their own they can cause problems during the winter. For optimal usage, these methods must generate enough heat to keep the water temperature in the safe zone. This shouldn’t be an issue during the summer if the weather is good enough, but UK winters simply aren’t warm enough to ensure such systems are safe.
Maintaining a balance between energy efficiency and Legionella control
Like the UK, many countries are looking at ways to become more energy efficient, and it’s easy to see why. However, we don’t believe we have seen any reports or news items on this topic that also mention the need to remember water safety as well.
The importance of water safety for manmade water systems could easily be overlooked by those planning a new build or planning adjustments to an existing building. Yet it is just as important as considering the practicalities of which services are needed now – and which services may be required in future.
While saving energy is admirable, it should never be done ahead of assessing the impact on water safety and public health. Legionella can grow and spread inside pipework, water tanks, and other areas of a system if it has the chance. Ideal water temperatures, stagnant water sitting in redundant or infrequently used pipework, and the inability to deliver water at hot or cold enough temperatures can all cause major issues.
The common-sense approach to managing Legionella
The good news is that managing the risk of Legionella is entirely possible. Common sense and the ability to understand and follow regulations and guidance such as the Health and Safety Executive ACOP L8, HSG274 and the Department of Health HTM 04-01 will help here. There should be someone experienced and qualified to carry out a Legionella risk assessment and to properly identify all the risks involved. If risks are discovered that link to energy saving measures, mitigating or removing those risks should come ahead of anything else. If this does not occur, the price for saving energy could be far higher than anyone would want to pay.
World leading water safety specialists
The environmental safety specialists at Legionella Control International help business owners and landlords, facilities managers and those responsible for workplace safety maintain good water quality and mitigate risks associated with Legionella and other waterborne pathogens to maintain regulatory compliance and keep people safe.
If you would like to speak with one of our environmental safety specialists call us today on 0330 223 36 86 or contact us here …
