Water treatment - targeting the cause not the symptom
Advancements in heating and cooling technologies have pushed the importance of water conditioning solutions up the agenda, but there's still much more that can be done to maximise efficiency and improve the whole life cost of a commercial system. Here, Martin Wilkinson of Spirotech UK, explains why
Traditionally, commercial heating and cooling systems were designed around central plant rooms featuring large cast iron boilers that were not only expensive to run, but were also extremely inefficient.
However, with the importance of energy efficiency gaining prominence and the introduction of legislative targets to reduce the carbon footprint of the UK's building stock, there have been major advancements in technology in recent years.
The good news is that despite the steep learning curve, the industry as a whole, from manufacturers and suppliers right through to specifiers and installers, have responded well and there's now a host of highly efficient solutions available, from condensing boilers and eco pumps for example, that the market is confident and competent at installing.
Importance of water quality
However, the growth of modern, more complex and expensive heating and cooling systems, whatever the application, does come with its own issues and probably the most crucial to maximising the efficiency of the system is water quality. It's a fact that these newer systems are extremely sensitive to air and dirt, so if these aren't taken into consideration and measures put in place to remove them, optimal system performance cannot be achieved or maintained. All the components now in a system will probably have an A or B energy label on day one of installation, but this will rapidly decline if the water isn't treated correctly.
All sorts of malfunctions and problems can occur if air and dirt are not sufficiently removed, significantly increasing the likelihood of a system breaking down and reducing the lifetime of the boiler or other valuable system components. This may also include elevated noise levels, the requirement for frequent manual venting, continual cleaning of strainers and the need to add additional chemical treatments.
The impact will be an imbalanced system and decreased pump performance, as well as the possibility of increased breakdown periods, excessive wear and higher energy consumption.
Ultimately, all of this will cost the end user more money in the long run and inevitably mean a more expensive maintenance programme and the chance that system components will have to be replaced more frequently.
Treat the cause not the symptom
Faced with these issues, specifiers and installers are now thinking carefully about deaeration and dirt separation solutions in system design by looking at the whole life cost of a project and not just the initial capital outlay.
There is still more that can be done though and the installation of these types of solutions are still in their infancy. In the commercial UK heating market for instance, dirt separation technology in the form of magnetic filtration to attract magnetite and remove pollutants and corrosion is fairly popular.
However, by going down the dirt route, installers are still only treating the symptom and not the cause. The biggest opportunity to ensure optimum efficiency and guarantee the quality of the system is by targeting the cause and removing the air through deaeration solutions.
Air gets into a system in a number of ways. Firstly, dissolved air is a natural element in water in the form of nitrogen, oxygen and carbon dioxide. Oxygen is the biggest culprit because when it reacts with pipework you get corrosion (hydrogen, methane and ammonia), which leads to magnetite. Secondly, air can also get into a system through a number of factors like an expansion vessel being too small or located at the wrong point, an incorrect initial fill pressure, mistakes in system design or pressure differences over regulating valves. Finally, air gets into a system when topping up and during maintenance work or through leakages.
Therefore, by adopting air removal technology from the outset, particularly in new build applications, you have the ability to prevent magnetite and corrosion from occurring in the first place. By removing the circulating air and micro bubbles effectively, this also greatly reduces commissioning time and maximises system efficiency.
Spirotech's solutions are based on its Spirotube technology, ensuring active deaeration and dirt separation with minimal fluid mixing.
The company has a consultancy approach to working, helping develop custom-made solutions and working with installers in the commercial (and domestic) heating industry from the design stages right through to installation and commissioning.
SpiroCross is a dirt separator and hydraulic deaerator in a compact unit that is suitable for the new build and renovation markets. By looking after the system on a daily basis, it removes dissolved gases and circulating dirt particles with no disruption to the operation of a system. The result is less energy consumption by circulating pumps and significantly reduced corrosion to ensure increased longevity of all wet system components.
Whilst the market for dirt and air separation solutions (or a combination of the two) is still a relatively new concept to the UK heating industry, particularly when compared to boilers, the fact that heating and cooling systems are getting more complicated means that these types of solutions are only going to be more important for delivering optimum performance.
The key is looking at the whole life cost of a project, and the fact is that by installing dirt and air separation technologies, it will reduce faults and wear and maintenance significantly, providing energy savings for the end user and a higher level of comfort for a building's occupants.
Advancements in heating and cooling technologies have pushed the importance of water conditioning solutions up the agenda, but there's still much more that can be done to maximise efficiency and improve the whole life cost of a commercial system.
// The author is the commercial manager at Spirotech UK //
2 April 2014