Mechanical and electronic products and controls producer Danfoss’s VLT drives include an HVAC drive that is dedicated to heating, ventilation, air conditioning and refrigeration (HVAC&R) applications.

Danfoss South Africa HVAC&R sales engineer Gordon Potts says that the Danfoss VLT HVAC system was launched two years ago after extensive research and development into global customer requirements for HVAC&R applications. He notes that the drive system is constantly being upgraded to accommodate market needs.

The latest upgrades of the drive system include the official approval of the data communication protocol for building auto- mation and control networks, as well as approval of the Siemens field-level network protocol for building management systems bus control in December last year.

The company also developed and installed a ‘sensorless’ pump control into the system that is able to calculate and control its own parameters. Further, Danfoss is now able to supply customers with Danfoss VLT HVAC systems of up to 1,2 MW, making it one of the biggest drive systems in the HVAC&R industry. Potts points out that the company is able to customise and tailor its drives to individual customer requirements.

He explains that the basic function of the drive is to run a pump or fan at speeds to match the requirements of the HVAC&R system. The drive is able to save energy owing to its efficiency of 98% during operation. The energy efficiency of the drive is also increased by its sleep mode, automatic energy optimi- sation mode and flow compensation.

Potts mentions that energy efficiency usually came second to the budget in most HVAC&R installations. However, he adds that in the wake of higher tariff rates and new legislation regarding the reduction in energy consumption in buildings, Danfoss is noticing increased attention being given to more energy-efficient products.

Further, owing to the drive’s design and a number of different options, it allows for low initial investments and low-cost upgrading in line with the customer’s future needs. Potts points out that additions and upgrades to the drive can be implemented at any time.

The Danfoss VLT HVAC drive is available in a number of versions, from the basic version with serial communication capabilities to a fully equipped personalised drive. Potts says that commissioning of the system is simple through its local control panel with 27 languages and a quick menu for easy motor adaptation and commissioning. The drive is compatible with most systems, he adds.

Challenging Times

Danfoss business unit manager Donald Fowkes believes that owing to the drop in commodity prices as a result of the global economic crisis, a delay in project orders is expected.

Further, Fowkes says that the drop in commodity prices, in particular for copper that is largely used in the manufacturing of the HVAC&R system, has also negatively affected the supply of product to the industry.

However, infrastructure developments for the 2010 FIFA soccer World Cup will ensure reasonable growth in the local building sector until 2010, Fowkes says.

He predicts that 2009 will be a difficult financial year, adding that Danfoss is planning to increase its visibility in the market and expects a turnaround in the economy by the end of 2009.