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Pump energy reduced

14 January 2020

When ECG, the company responsible for managing Edinburgh landmark office building Exchange Plaza, decided to look for ways to reduce the energy used by 16 pumps in the building’s HVAC systems Pump Action was approached to carry out an assessment. In turn, Pump Action contacted Greenville, a Premium Danfoss Drives Partner.

Steven Brown, Business Development Manager at Greenville, working in conjunction with Pump Action, assessed the condition of the existing pump systems and provided a report on their efficiency, as well as to suggest improvements.

"Working with Pump Action, we produced detailed energy saving calculations and concluded that the building and its inhabitants would be much better served by the installation of new pumps and new AC Drives," said Steven. "The existing installation had old, inefficient pumps with either DOL or star/delta starters and so they could only run at full speed. Our proposal was to install new efficient pumps along with variable speed drives (VSDs) so that the pump speed could be regulated to match demand. ECG accepted our joint proposal, so we supplied the VSDs to pump specialist Pump Action, who installed them alongside new pumps."

"We were asked by ECG to look at upgrading the pump equipment which was 25 to 30 years old," explained Colin Ramsay of Pump Action. “We selected modern high efficiency pumps to complement the new Danfoss drives. The whole refurbishment process took two weeks to complete and there was no disruption to the tenants’ activities. We use Danfoss products a lot, and they are our go-to drives, not least because of the optimisation feature which makes them easy to set up to give the best performance.”

The VSDs installed at Exchange Plaza HVAC system are Danfoss VLT  FC102 HVAC types. These drives provide optimised process control in heating, ventilation and air conditioning (HVAC) applications. Easy to use and to install, they feature a wide range of functions specifically developed for use with pumps, fans and compressors to save energy, meet environmental regulations and reduce costs in modern buildings.

The drives feature compact construction and are available with power ratings from 1.1kW up to 1.4MW. They are an excellent investment with a short payback time in upgrade and refurbishment applications, especially as a wide range of control, I/O and communication options are provided as standard.

The new drives at Exchange Plaza have been configured to suit each pump in the system using the AEO (Automatic Energy Optimiser) within the drive functions, which typically reduces running costs by 5% to 15% compared with drives that do not have AEO. Automatic Motor Adaption (AMA) was also performed on the drives at commissioning stage, ensuring the drives and motors are optimally matched. Among other things, AMA takes into account cable inductance and motor winding resistance to fine tune the drive for each individual motor, thereby maximising overall efficiency.

An independent energy report from consultants Hulley & Kirkwood, carried out after the installation of the new pumps and drives, found that energy consumption was reduced by £3,500.00 per annum, from a figure of £11,162.00 before the upgrade work was carried out. This is an impressive saving of 31.7%.

Andrew Wilson, the ECG manager who was involved in the project from the very beginning, said: “We look after the Exchange Plaza building and it is our job to keep costs down while ensuring that the tenants continue to enjoy maximum comfort. Greenville has helped us on a number of occasions and now it was instrumental in supporting Pump Action’s installation on our site. We are very pleased with the results and so are the tenants. Danfoss drives are helping us to operate more efficient and cost-effective systems that are also in line with our environmental policies. We are extremely pleased with the support received from the Danfoss Partner, Greenville, and we’ll undoubtedly be collaborating with them again in the future!”