Page 18 - Climate Control News Dec-Jan 2020

Hot Products
High on expertise to solve low Delta T
LEFT: The energy valve supplies the BMS system with the information it needs to control plant in the most energy efficient manner possible.
ergy Valves, they thought that this was the end of the journey. “However, you cannot treat energy efficiency like Jenga; it works more like a dot to dot. You get a few components that help deliver the picture but it’s the system overall that has to be configured to deliver the results,” he said.
So how does the energy valve work?
The Belimo Energy Valve is an electronic pres- sure Independent valve, with BACnet and Mod- bus capabilities both over IP and RS485. Put sim- ply, it supplies the BMS system with the information it needs to control plant in the most energy efficient manner possible.
The BMS simply looks for the furthest open valve, or 'thermal index' and scales the flow tem- peratures from that. All the other AHU's Delta T is maintained by the Energy Valve using its pat- ented on-board Delta T manager to ensure good Delta T is maintained at all times.
Pump Control is achieved by looking at the physical rotation of the valve. This is primarily a function of pressure. This point gives the amount of rotation required to deliver the re- quired flow, so the lower the valve position the greater the pressure.
“We can simply look for the hydronic index, such as the most open valve, thus it could be any electronic valve in the system, on a branch fitted to an AHU,” he explained.
“Using this information the BMS simply re- duces the pump speed until the furthest open valve is as far open as we would like.
“Bypass control also plays a part with inter- locks preventing increases in pump speed or reductions in flow temperatures until the by- pass is closed.
“Of course it's not that simple, and each build- ing is different and we have people to help get you and the building ready.”
Contact Belimo on 03 8585 7800
BELIMO ACTUATORS PTY Ltd managing di- rector, Duncan Jenkinson, talks to CCN about the unique features of the Energy Valve that made it one of the hottest products of the year.
He said the Energy Valve was able to set itself apart from the rest of the market because indus- try has realized energy efficiency isn't simply a product anyone can buy or sell.
“It requires a certain level of expertise. In order to achieve that next NABERS star, or a decent re- duction on energy bills, it requires a system of complimentary products working together,” Jen- kinson said.
“If you look at the market, particularly when it comes to solving low Delta T syndrome to better achieve efficiency, there are a number of prod- ucts out there that claim to solve this problem; in reality it is never that simple.
“We know how to solve low Delta T because we know what causes it. It means there is more energy available to a heat exchanger than it can
exchange, either through water temperatures that are too cold, flow rates that are too high or air volumes that are too low.
“Due to the dynamic nature of VAV AHUs they often have this problem and we have seen a number of technologies come onto the market promising to be a one stop solution,” he said.
“However, we know that central plant based chilled water reset is fooled by mixed load condi- tions especially for AHU's serving different ther- mal zones.
“Equally, plant optimisation that simply in- creases flow temperatures until a valve is fully open puts the chiller in a less than efficient posi- tion by going too low with the loading; even the most efficient chillers will plateau.
“Therefore we need a better system and more data to effectively control the whole building. The device which delivers that data is the En- ergy Valve.”
Jenkinson said when some clients installed En-
TRUSTED FLOW MEASUREMENT
Trusted flow measurement is essential in maximising HVAC system efficiency and ensuring occupant comfort.
Belimo has released new larger sized inline flow sensors from DN65 to DN150. Belimo's new flow sensors utilise ultrasonic transit-time technology to provide accurate, repeatable flow measurements of water and water/glycol mixtures without drift in any HVAC application.
The innovative measurement method features ±2% accuracy of reading and ±0.5% repeatability, ensuring accurate and precise flow measurement and low power consumption of
0.5W, saving energy and transformer capacity. Its ultra-compact size with a short inlet length
of 5x nominal pipe diameter and no output- length requirements allow the ultrasonic flow sensor to be installed in tight spaces. Multi-point wet calibration enables hassle-free installation and accurate flow measurement from start-up.
The comprehensive diagnostics functions feature an automatic air-bubble and water presence detection. These make the installation and commissioning easy and efficient.
Discover more: https://www.belimo.com.au/ en_GB/flowsensor
The sensors are designed to make commissioning easy.
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