Heating and Ventilating

WITH the implementation of the amendments to Part L of the building regulations, the desire for greater off-site assembly and the move towards packaged solutions, there has probably never been such a period of concerted development within the fan coil industry.
In common with other manufacturers, Quartz has been developing versions of its fan coils that incorporate ec/dc motors.

Quartz's approach differs, says the company, from other manufacturers in two main areas:

· It has invested considerable research time in reducing the effects of the harmonics generated during the rectification and electronic commutation processes that such motors require. This work was prompted by some wildly optimistic claims regarding running currents, made when the new motors were first launched into the market.

· It has also devoted development time to the application of these motors and controllers in order to offer drastically reduced on-site commissioning time, thereby providing a significant reduction in labour costs on site.

The prime market driver for the use of these motors is in the energy-saving benefits they bring, which offer substantially lower whole-life costs. Typically, dc motors show performance improvements of 55% over their ac counterpart. While these figures appear impressive, the losses referred to above in relation to dc motors can be perceived as substantial and should be reduced to a minimum. It appears that the exaggerated claims were made in an attempt to hide the extent of the conversion/harmonic losses.

Spurred on by such deceptive marketing, Quartz has been examining ways to reduce or eliminate this loss. Development of the filters to be used in the system has resulted in substantial loss reduction, providing a product that is way in advance of its competitors. Quartz is also involved in developing units with their own active power factor correction which will almost eliminate loss and ensure the Quartz brand continues to offer the most energy-efficient products for the future.

Not satisfied with simply improving the component efficiency, Quartz continued its investigations in order to identify how the specific features of these motors could be best applied in order to make further savings on site. The major development in this area relates to the dc motor's ability to be infinitely speed controlled. Using this feature with a suitable controller, Quartz has developed a product which can self-calibrate by automatic adjustment of the fan speed to achieve the design airflow condition when installed on site. The feature recognises the external pressure drop of the discharge side of the fan coil and dramatically reduces or eliminates the requirement for air-side commissioning.

To promote the use of these motors, pass on the knowledge gained during the development and ensure designers have the correct information, Quartz has produced a booklet entitled Everything You Wanted to Know about AC\DC Motors (but were too embarrassed to ask!). This will be available soon free of charge as a hard copy booklet and as a download from the website www.quartz.co.uk.


Tev T: 01484 405 630 or info@quartz.co.uk