www . refrigerationandaircon . co . za RACA Journal I January 2024 25
Feature power saving for the end user . They ’ ll pay more from the start but get their money back from power savings , normally well within two to three years . Unfortunately , it is often about the capex rather than opex . The mechanical engineer designs the system according to the client ’ s budget and it is the price of the system that ultimately determines which solution they go for .
“ However , when a building is aiming for green star rating certification from the Green Building Council SA ( GBCSA ) they will certainly budget for PICVs in order to get the energy savings and the points . As green buildings are being pushed quite extensively , we have been seeing an increasing adoption rate over the past 10 years . However , there are still plenty developers who are not worried about their client ’ s energy usage because of the upfront cost ,” adds Hofmann .
He notes that Danfoss PICVs can be retrofitted to existing two-way systems . “ It is messy work – but there is no question that it will pay for itself in a very short time .”
FEATURES AND BENEFITS
• Easy setting and sizing : Selecting the right AB-QM is much less complicated than sizing and selecting conventional control valves . Once the design flow is determined the matching AB-QM can be selected , no additional Kv and authority calculations are required .
• 100 % authority : Having a 100 % valve authority increases the control quality and precision , also at low flow requirements . This creates a better comfort in the building , as well as increasing the energy savings .
• Perfect control : By providing the right flow at the right time , the AB-QM optimises chiller and boiler efficiency and reduces pumping costs . In addition , the actuators need to make much less movements , increasing the lifetime value and lowering the Total Cost of Ownership .
WHEN COOLING SYSTEMS ARE EXPOSED TO THE ATMOSPHERE Cooling towers are often open to the atmosphere , which exposes them to outside elements . To combat this issue , it ’ s typically required to treat the water with a series of decontaminants that will aid in the slowing of corrosion and erosion caused by the chemicals and foreign particles in the water that is used to cool the system . Closed systems may be used for smaller cooling applications .
Choosing the best piping for a cooling system is a crucial part of the assembly process . There are five types of piping that can be used for a cooling system : tubing , iron , steel , stainless steel or exotic alloys , and plastic . The size and type of piping that should be used in the system is determined by factors such as the desired velocity through the system and compatibility with the fluid and chemicals that need to be introduced into the system to ensure efficiency .
Automated Control Solutions Automated Control Solutions
Danfoss ABQM FCU Valve and actuator installed in very tight space .
Danfoss ABQM DN150 installed at a local data centre .
The size of the piping is important but can easily be determined by how much water needs to flow through the system . Higher grades of piping material come with a higher cost but will help with longevity and reliability . The compatibility of the piping system is important because water will be running through it at a near-constant flow rate . As the flow rate of water increases , a more chemically resistant pipe material is required to better hold up to corrosion .
If there is corrosion within the piping system , there can be a number of issues , including leaks within the piping system where
“ It could be a needless expense to buy an extremely precise and more expensive control valve when a less precise one could have done the job just as well .”
www . refrigerationandaircon . co . za RACA Journal I January 2024 25