Energy saving quest momentum

Fans & Spares, the UK's leading heating and ventilation equipment distributor, reports a marked increase in demand for AC motor controls as a result of the Climate Change Levy (CCL). The company supplies Yaskawa AC variable speed drives into the UK market and has witnessed greater awareness of energy consumption among its customers, such as evidenced by a recent project for Land Rover. Businesses have had a year to assess the impact of the increased energy costs created by the CCL. At the same time, there has been a period in which the offset benefits, such as the Government's Enhanced Capital Allowances (ECA) have become better understood. Land Rover, for instance, ordered Yaskawa inverters (variable speed drives), for the intake and extraction fans for two engine test beds at its Gaydon site. These 1100mm diameter axial fans, also ordered through Fans & Spares, control the test area ambience by replacing hot exhaust fumes with clean air.

Fans and Spares last year entered into a partnership with Yaskawa to supply energy saving E7 and Mini J7 inverters. Paul Carberry, Fans and Spares' commercial manager, reasons that increased interest in the Yaskawa products is due to the rapid payback in energy savings coupled with the installation cost benefits under the ECA scheme. Under the ECA, 100% of the capital equipment and associated installation costs can be offset against income tax in the first year. Yaskawa E7 inverters qualify for the ECA because they are on the Energy Technology List approved by DEFRA.

In many HVAC applications it is desirable to vary the speed of fans. Because of the nature of airflow from the fans, some applications can benefit from a reduction in speed with no significant loss of airflow performance. In these cases energy is saved as a function of the square of the fan speed, hence a speed reduction from, say, 50Hz to 47Hz can result in minimal loss of air flow, yet result in substantial savings in electricity consumed.
A measure of the ongoing savings that can be made is to consider that a relatively modestly sized 11kW AC induction motor can cost as little as £300 to buy. The running costs of such a motor over a ten year period could be more than £30,000 according to the UK Government's Energy Efficiency Best Practice Programme's Guide.

One of the issues in the HVAC marketplace is the ease with which AC drives can be installed into both new and existing systems. Single or three phase, E7 and Mini J7 inverters, simplify installation by automatically tuning themselves to the motor to which they are fitted. The drives can be programmed using easy menu commands, either through the drive's front panel or via a PC that can be plugged into the unit for download (useful when multiple drives are being programmed identically).

A requirement for HVAC applications is the quietness of the drive. Here, according to Fans and Spares, Yaskawa has a technological lead over its rivals, offering an exceptionally quiet device that is ideal for the application. A feature of the E7 inverter is its PI constant flow control that enables a consistent air flow in fan applications, reducing the chance of vortices in the system that can create noise.

Released: September 2002