The Importance Of Water Quality When Using PICVs

13 August

There are so many factors at play when it comes to keeping our hydronic systems efficient and reliable, and one of those that can get overlooked is the quality of the water itself. We can continue to invent, build and install the most hi-tech and effective systems in the world but if the water quality is poor, this can have a detrimental effect on our hardware, such as our range of PICVs.

Before we look into the water quality features, let’s first talk about standards, because there are three serious standards we need to focus on, which will help us set up and control our water systems. They are BSRIA BG29, BSRIA BG50 and VDI 2035.

BSRIA BG29
BG29 is a water quality standard which is followed before an HVAC system is operational. The standard was first introduced by the Building Services Research and Information Association (BSRIA) in 1991 and has gone through various additions, modifications and amendments but the core elements have stayed the same. Following the BG29 standards ensures that your water in HVAC systems is clean and flushes without any debris or fragments contaminating it. That is, if the standards are followed correctly. While the BG29 is not a legal requirement, failure to comply with the standards will result in damage, corrosion and failures. Some important notes to takeaway from BG29 include:

• Pre-cleaning: BG29 is only used for preparing a system, so it contains a lot of information regarding initial setup. It may seem that a brand new system installed new might be ready to go straight away, but a great deal of work still has to take place so that it is optimal for the project.
• Flushing: A primary and secondary flush must be conducted to ensure the system is running correctly. It is entirely possible that dirt and debris has made its way into the system from the busy installation period, and not flushing this out before use would be damaging.
• Monitoring and reporting: The standards of water must be compared with established standards and multiple checks must be made to ensure the system flushes at with regular positive results.

BSRIA BG50
We’ve established that BG29 is the starter kit of standards, and is there to ensure the system is ready to go. Once the HVAC system has been install  ed and begun operations, then we switch to BSRIA BG50. BG50 is another set of standards (122 pages compared to BG29’s mere 110 breezy reading) which lay down the standards for maintaining the conditions that BG29 set up. Once you have your spotless system to begin with, the guidelines you will go on to follow will ensure the system is as reliable and as efficient as possible, for as long as possible. Corrosion and bacterial growth will be at an absolute minimum if the guidelines of BG50 are followed and the recommended regular maintenance adhered to.

The benefits of adhering to both these standards are noteworthy, but it comes down to absolute basics: a cleaner, maintained system, will last longer and be more reliable. An efficient system operating at optimal capacity will reduce the amount of unplanned downtime, and as such will lead to cost savings. The longevity of the system will improve and the overall quality of the building will remain higher for longer.

Other key components of BG50 include:

• Procedures: The standards offer you the correct methodology of performing system flushing to remove debris to prevent a blockage, performing inspections of strainers and filters, and monitoring the dosage and ratios of chemicals.
• Corrosion inhibitors: The BG50 standards recommend the use of corrosion inhibitors for protecting the metal components within the system. Only in the most recent version of BG50 has BSRIA acknowledged dissolved oxygen as a contributing factor to corrosion and provides an in-depth guidance on treatment techniques.
• Documentation and training: It’s not just the hydronic system that requires professional attention. Detailed records should be kept, making sure that the maintenance and inspections are consistent and up to code. Any and all staff involved in the documentation of such work should be fully trained so that there are no gaps in the knowledge of the workforce.

There’s also the consideration of compliance. Although not a legal requirement, many projects will not get off the ground without BG29/50 adherence.

VDI 2035
There’s one more standard you should be aware of: VDI 2035. Because, as useful, in-depth and assertive the BSRIA BG29 and BG50 standards are, they are only used for treatment and maintenance of UK systems. VDI 2035 is an internationally-recognised standard, used across Europe to achieve similar results. It returns a lot of the same recommendations as BG50, including limits on the hardness and pH of the water in a system and maintenance procedures and materials to ensure the longevity of the system.

VDI 2035 sets very specific limits on water hardness, which prevents the build-up of scale, and focuses on preventative measures to avoid scale and corrosion from the beginning, ensuring efficient and reliable operation. BG50 recommends the pH of the water does not dip below or rise above a set limit and emphasises the importance of ongoing maintenance and monitoring the quality of the water, protecting the system from deterioration and maintaining its efficiency over time. Additionally, both documents contain detailed instructions and recommendations for ongoing system checks and maintenance.

So, using these standards, what can we conclude about the importance of water quality?
The stricter a system obeys BG29/50, the less impact varying water quality will have. That is not to say that there will be no difference, and without maintenance, harder water will corrode a system faster than soft water, but preventative action will always help. Hard water can produce calcium and magnesium, which create scale buildup when heated. This scale can reduce the effectiveness of heat transfer, leading to pipes taking longer to heat up, meaning the system uses more energy to get pipes up to the heat intended and therefore reduce the efficiency of the system. Additionally, this sort of build up can slow down water flows as the fluid fights to get through a smaller gap than before. Regular flushing and cleaning in accordance to the BSRIA BG50 and VDI 2035 standards will prevent this, or at the very least, reduce it to an acceptable level.

Hard water can also lead to corrosion quicker. If it contains oxygens or other chemicals such as chloride, pipes and valves could weaken over time. PICVs can be an integral part of a maintenance regime of heating or chilled systems to maintain water quality at low flow conditions. BMS control can be used to increase flow where low flow conditions are present. Allowing a forward and backward flush is also important part of maintenance where our Floset allows this in line with BSRIA standards.

In short, the water quality is important but regular maintenance, following the strict standards of BG29 and BG50 and equipping yourself with the strongest FloControl PICVs will keep your system in check, and running for years to come.

FAQS

What is BSRIA BG29 used for?

BSRIA BG29 is a standard that outlines pre-commissioning cleaning and flushing procedures for HVAC systems to ensure optimal water quality.

What is the importance of VDI 2035 water quality guidelines?

VDI 2035 water quality guidelines focus on controlling hardness, pH, and oxygen content to prevent corrosion and scaling in HVAC systems.

Why is BSRIA flushing necessary before system start-up?

BSRIA flushing helps remove debris and contaminants from new HVAC installations, protecting components like PICVs from early failure.

What does BSRIA water testing involve?

BSRIA water testing involves sampling, analysing, and comparing water conditions to established benchmarks during and after system flushing.

How often should BSRIA BG50 procedures be followed?

BSRIA BG50 procedures should be followed continuously after commissioning to maintain system efficiency and reduce corrosion risk.

Is BSRIA BG29 legally required?

No, BSRIA BG29 isn’t legally mandatory but is widely regarded as best practice and often required by building project specifications.

What makes VDI 2035 different from BSRIA guidelines?

While BSRIA BG29/BG50 are UK-focused, VDI 2035 water quality is a European standard that provides even stricter water treatment criteria.

Can poor water quality damage PICVs?

Yes, poor water quality can lead to scale and corrosion buildup, reducing the performance and lifespan of PICVs in hydronic systems.

How does FloControl support BSRIA water standards?

FloControl’s PICVs and FloSet systems support forward and backward flushing, aligning with BSRIA flushing and maintenance recommendations.

What happens if BSRIA water testing is ignored?

Ignoring BSRIA water testing may result in increased system failures, poor energy efficiency, and higher long-term maintenance costs.