Energy saving incentives for retrofitting VSDs

Installers of new plant and equipment, can be confident that it is energy efficient. The UK Government encourages the use of energy efficient equipment through tax and investment subsidies. The Carbon Trust’s Green Business Fund provides more guidance on these programmes, including when retrofitting VSDs and other energy saving equipment.


Retrofitting VSDs

There are enormous opportunities for retrofitting drives in variable flow applications across the HVAC industry. ABB estimates are that in the UK only one in four motors used in HVAC applications have variable speed control.

Pumps and fans are the best applications for retrofitting VSDs, and the larger the motor, the greater the saving. The best of these are that have:

  • a single large pump or fan rather than a series of staged pumps or fans that come on sequentially as the process needs increase
  • variable flow, where throttling (by valves or dampers) provides the variation and where most of the operation is below the design flow.
  • operating hours of more than eight hours per day

An energy audit will help plant owners identify the many pumps and fans benefiting from retrofitting VSDs.

Energy audit

For a company to reduce energy costs, it needs to know how and where it uses energy, and this is usually in the form of an energy audit. An energy audit provides a systematic examination of key pump and fan applications including the monitoring of energy consumed. This allows estimation of the expected energy saving and payback period.

The initial capital investment in substituting inefficient control methods such as vanes and valves can be high. However, the large amount of energy saved results in shorter payback periods.

There are many additional benefit from making theses changes.  These include, higher comfort levels for staff due to better temperature and ventilation control, lower noise levels and reduced maintenance costs.

All VSDs are not equal

Many manufacturers produce general purpose and machine control variable speed drives. However, the HVAC industry has many industry-specific requirements. ABB produces a wide range of drives specifically for HVAC applications. They include ACS320, ACH550 and ACH580 Series.

Go here for more ABB energy saving drives

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