Heating and Ventilating

Martin Wilkinson firmly believes that a holistic approach to water conditioning and its control - from bottom to top level system management - is vital to achieving efficient, reliable operation and longevity of plant
Water treatment alone cannot solve every system problem. It is vital that you get to the root cause of the issues affecting your heating system.

Water has to be closely managed for a system to run to optimal performance.

Simply dosing with chemicals alone isn't going to solve deep-rooted system issues, as there are several different but inter-related factors that can have a detrimental effect on water quality and wider system health.

Water conditioning should be viewed as an imperative when it comes to commercial heating systems - not just a 'to-do' box ticked!

Poor water quality is the major cause of component failure in wet systems, so informed advice, from an established company with proven problem solving capabilities, is vital in ensuring that a range of issues - from corrosion damage to system failure or even bacteriological contamination - are avoided.

For example it's important to recognise that air may be getting into the system through poor pressurisation, design installation or inadequate maintenance.

While chemicals do, of course, have a part to play in the equation, they are not a cure-all, so other steps need to be taken to prevent corrosion rather than simply slowing the rate of corrosion by dosing with chemicals.

Although the need for effective water conditioning in low-temperature hot water and chilled water systems has previously been viewed as a low priority, today's professional specifiers and consultants have recognized the vital role played by high performance dirt separators, de-aeration and pressurisation products in heating system performance.

Dealing with any problems at their source and not attempting to mask them is essential in order to gain and retain energy efficiency and uptime.

I would strongly suggest that you identify proven specialists in this field who can provide a turn key solution.

Applying the solutions advised by a specialist company such as Spirotech at the installation stage on new systems or mid life cycle on existing systems retains system performance and offers preventative maintenance benefits relating to components such as valves, pumps, heat exchangers, boilers, chillers.

Hydronic Stability
Hydronics is the use of water as the heat transfer medium in heating and cooling systems and good 'Hydronic Stability' is the foundation for a healthy system that will last for years and provide optimal performance.

Hydronic stability - and the resulting system efficiency - make a significant contribution to operational cost savings, energy usage and ongoing repairs and maintenance.

The four elements that must be addressed to promote optimal conditioning of the system water are listed in the following order of importance:

Pressurisation

Deaeration

Dirt Separation

Chemicals

The inter-relation between these elements is important in developing an effective water conditioning regime.

A specialised company, with proven problem -solving expertise and an innovative high performance product portfolio in all of these sectors will have invaluable knowledge of the issues that affect hydronic stability.

The specialists will conduct a thorough check of the initial system design and all vital elements affecting hydronic stability is necessary to get to the root of the problem.

The initial design input versus actual performance would also be reviewed - establishing whether the design has been implemented correctly and maintained as appropriate.

Pressurisation
Firstly, it's important to achieve the correct pressurisation, which is key to hydronic stability.

Other measures such as air and dirt separation, and the appropriate introduction of chemicals and protectors, also need to be considered in order to maintain a healthy system.

These would take into consideration the parameters of the water or heat transfer fluid within the system so a tailor made solution would be devised by the specialist advisors in order to solve system problems or to prevent future problems arising.

This makes a valuable contribution to improving the overall quality of the system fluid and this in turn helps to lower fuel consumption, thus resulting in reduced carbon emissions.

Europe
We need only to look at the rest of Europe to see the benefits of relying on correct initial design and stringent maintenance of plant and equipment.

As a global operator, Spirotech is well aware of the European marketplace where there is a strong reliance on 'natural passivation' of the system fluid once the final fill is completed and the use of artificial intervention - dosing with chemicals chemicals - is far less prevalent as a consequence.

Deep-rooted system problems relating to air ingress and dirt build up are significantly reduced in view of the preventative maintenance measures taken from the outset.

Indeed, not all systems need water treatment as such.

A system that has naturally passivated - hydronically stable - and remains without air ingress, frequent refill or other chemical introduction could function well for some time - until the hydronic stability is compromised and triggers a chain of events, that if left unchecked, could lead to ultimate system failure.

Driving change
The most recent British Standard and BSRIA recommendations have sharpened the UK's focus on the vital importance of an ongoing, long-term strategy for water conditioning.

These are both steps in the right direction when it comes to alerting the industry with regard to the importance of instituting all-encompassing water treatment regimes within commercial heating systems.

The BSRIA guide BG29 was revised in 2012. This document provides guidance on 'pre-commission cleaning of pipework systems'. It clearly states that 'persistently high oxygen levels will greatly increase the risk of corrosion even where the system is properly treated with inhibitors'.

The guide goes onto say that it is appropriate to install vacuum degassers to speed up the reduction in oxygen levels and therefore lessen the risk of corrosion damage.

The new British Standard code of practice was introduced in November 2012.

The publication is BS8552 Sampling and monitoring of water from building services closed loop systems.

Companies must now ensure that when water samples are taken from the system it must be carried out in accordance with the methods laid down in this publication.

Clearly today's UK commercial marketplace is beginning to acknowledge that a holistic approach to water conditioning and system health is much more than an optional 'nice to have'.

It needs to be viewed as an imperative, a fundamental aspect of commercial system design that makes an important contribution to overall system health, operational efficiency and energy consumption.

// The author is national sales manager at Spirotech UK //