Combat rising HVAC energy costs

Building owners and facility managers are continually look for ways to save energy and money. Recent government regulations and the rising popularity of the “green building” concept have led to highly energy-efficient new building, but what about older buildings, and will retrofit projects that achieve energy efficiency to benefit the building owner and occupants?

Since HVAC systems are huge energy consumers, highly efficient systems offer the opportunity for great energy savings. HVAC equipment offering opportunities for energy savings including centrifugal air handler fans and exhaust fans, centrifugal pumps for hot and cold water, cooling tower pumps and fans. To meet demand for environmental protection, UK and European energy legislation, and improving and corporate profitability Schneider Electric developed their ATV212 and ATV61 drives for HVAC applications in buildings.

The good news is where motors are used for pumping fluids (e.g. water and air), installing variable speed drives (VSDs) to the pump motors offers disproportionately large savings in energy.  In conventional systems, the motors run at full speed all the time, whilst dampers control airflow, and valves control liquid flows. Instead of these control methods, using VSDs the motor speeds is reduced to match the demand.

Disproportionately large savings

The reason savings are disproportionately large is down to the way electric motors work: operating at full speed they take their full energy, but reducing the speed to say 80% reduces the energy required by nearly 50%-see here for more on how this works. This gives payback times acceptable to most users.

Payback Period of Variable Speed Drives

The payback period of a VFD averages 18–24 months but can be less than 12 months. The period depends largely on the type and size of the system and how much time the motor is operating at full speed versus how much flow is actually required to heat or cool the building space. The life cycle of HVAC equipment in commercial buildings is typically 15–20 years, so a one or two-year payback period can generate a substantial return on investment.

Other Benefits of Variable Speed Drives

Variable speed drives also contribute to the building’s overall comfort level by optimizing and regulating air flow and temperature into the building’s occupant space. Unlike a fan that runs either full speed or off, a variable speed drive can run at all speeds in between, allowing facilities managers and building occupants more control to adjust the temperature. The Schneider Altivar ATV212 and ATV61 ac variable speed drives take occupant comfort one step further with accurate flow control and a modulating output switching frequency to reduce noise pollution caused by motor operation.

In addition, VFDs reduce the long-term wear and tear on equipment. The drives provide a soft start instead of slamming motors on at full speed—so HVAC systems last longer, requiring less maintenance and causing fewer instances of unscheduled downtime.

Go here for ATV212 HVAC drives from 0.75 to 75 kW

Go here for ATV61 HVAC drives from 0.75 to 800 kW