In today’s ever-evolving landscape of commercial infrastructure, ensuring energy efficiency and system longevity in boiler systems has become more crucial than ever, says Spirotech’s Dean Oliver.
When heating a sprawling university campus, a multi-building school, large warehouses or a large factory, one of the most critical – yet often overlooked – aspects of system performance lies in the quality of the water circulating within the heating loop.
Achieving optimal water quality is not just about preventing corrosion or limescale. It is about safeguarding the entire system’s integrity and efficiency, now and into the future. Central to this is the effective removal of air and gases from the water, which is where products like vacuum degassers and deaerators play a pivotal role.
Why air is the enemy
Air may seem harmless, but within a closed-loop heating system, its presence can be disastrous. Oxygen and other gases dissolved in system water can cause accelerated corrosion, damaged components, loss of heat transfer efficiency, and increased maintenance costs. Even microbubbles can impact circulation and heat exchange, leading to cold spots and inefficiencies.
The installation of vacuum degassers and deaerators has been designed to combat these threats but operate differently within a system.
A deaerator is installed at the hottest point – on the flow side of the boiler and, as the water heats up, the gases dissolved in solution are then liberated. The resulting microbubbles are caught, coalesce on our Spirotube, then rise and are expelled through the automatic air vent.
Our SpiroVent deaerators remove the microbubbles and circulating air left behind by automatic air vents, or after bleeding valves. The product also prevents dirt formation and related negative effects on energy efficiency, failure sensitivity and wear and tear.
A vacuum degasser – such as the Spirotech SpiroVent S400 – can be placed anywhere in the system and subjects water to a very low pressure, far below atmospheric pressure, and this releases the dissolved gases. It uses the principles of Henry’s law – the effect of pressure and temperature on the absorbent capacity of water in degassing situations, to keep the entire system fluid at its lowest possible dissolved gas content.
SpiroCombi deaerators/dirt separators are designed for the simultaneous removal of air and dirt from water systems – removing air, microbubbles and dirt particles from system water continuously.
Don’t underspecify
Under-specifying a boiler system for warehouses – particularly regarding water treatment – can lead to a host of expensive and operationally disruptive issues:
Corrosion and fouling: Without effective air removal, oxygen corrosion can degrade components from the inside out.
Reduced efficiency: Air in the system acts as an insulator, reducing the heat transfer efficiency and increasing fuel consumption.
Pump cavitation: Entrained gases can lead to cavitation in pumps, leading to premature wear or failure.
Poor scalability: Systems not designed with future demand in mind may require complete re-engineering during expansion, rather than simple scaling up.
In contrast, specifying a system that includes modular degassing and water treatment solutions offers flexibility. If the heating demand increases, the treatment systems can be expanded or upgraded without significant disruption.
Water quality link
In commercial boiler systems, especially in large-scale applications like schools or industrial facilities, poor water quality can have cascading effects. The consequences can range from a slight drop in thermal efficiency to system failures that disrupt operations.
Water treatment strategies that include degassing are not just for performance optimisation – they’re risk management tools. With enhanced water quality, boilers run closer to their design efficiency, experience fewer breakdowns, and have significantly longer lifespans.
But installing a vacuum degasser or deaerator is not a one-size-fits-all solution. It must be part of a holistic approach, rooted in a deep understanding of the specific boiler system and the broader application it supports.
Specifier’s roadmap
For specifiers, the starting point should always be a comprehensive assessment of the heating demand – both current and projected. Key considerations include:
Current load and system size: What is the total output requirement? What type of boilers are being used?
Water source and chemistry: What is the oxygen content, hardness and potential for scaling or corrosion?
System layout: Are air separators already in place? They should always be installed at the hottest point of the system. The vacuum degasser can be placed anywhere within the system. As buildings have grown in size, the requirements for larger, more powerful degassers have grown. The height of a building determines how much pressure – from top to bottom – will be created in the system. Therefore, it is vital to correctly size the units and ensure the pump within the degasser is powerful enough for the job – it’s no good using a small pump if pushing against a system pressure of 10 bar, for example.
So for expansion potential: Is the site likely to grow? Is future expansion of the warehouse facility planned?
And for control systems, is there the requirement for a robust control system that can integrate seamlessly with BMS (Building Management Systems)?
A specifier who carefully maps out these variables will be better positioned to select not just the right boiler, but also the supporting solutions such as air and gas removal equipment, to ensure the system runs efficiently.
Conclusion
Water quality is a crucial element in any boiler installation. Without getting this right, even the most efficient boiler will underperform and suffer from premature failure.
The inclusion of vacuum degassers and deaerators as part of the water treatment is essential.
Specifiers play a pivotal role in ensuring that commercial heating systems are not only built for today’s demands but are prepared for tomorrow’s growth. Through meticulous planning and smart specification – particularly around air and gas removal – they can design systems that are more reliable, efficient and resilient, protecting both operational budgets and long-term sustainability goals.
In short, if you want your boiler system to breathe easy, remove the air.
