Fan upgrade helps cut energy costs

HVAC systems are typically responsible for 60% of a building's energy consumption, so reducing the energy impact of these units can be very rewarding for building, energy and facility managers. One of the simplest ways to reduce energy consumption in a commercial building is to ensure all HVAC equipment is fitted with the highest efficiency ‘EC technology’ fans.  

EC motors are brushless DC motors powered by AC mains. They use permanent magnet motors, running on high voltage direct current (DC) electricity, with built in AC to DC conversion, allowing them to run direct from single phase or three phase mains supplies. The result is high performance, silent speed control and long-life expectancy in a product which is the same size as the old, power hungry AC products it replaces.

However, it’s not always financially viable to upgrade entire HVAC systems. This article explores the five core benefits from upgrading only the ‘fan’ component of a HVAC system to EC technology. These systems include air handling units (AHUs), computer room air conditioning units (CRAC), chillers, condensers and fan coils units.

Energy savings = financial savings

In partnership with AB Group, we helped Marks and Spencer achieve energy savings in excess of £500,000 by upgrading to EC technology. A total of 1404 fans and 258 condensers were installed to 152 stores across the UK and Ireland. Following the upgrade, there is an estimated annual energy reduction of 3265.3kWh per fan, equalling a saving of £375.51 per fan and representing an annual saving of £527,223. 

Reduced carbon emissions

Since the Climate Change Act 2008, the UK Parliament aims to reduce the UK’s greenhouse gas emissions by at least 80% (from the 1990 baseline) by 2050. 

As a result, when ebm-papst presented the Scottish Parliament with details of the energy savings achievable by upgrading their HVAC equipment to EC fans, a survey was requested. Working alongside equipment manufacturer Airedale, we upgraded the CRAC units and AHUs to the optimum solution EC fan. The project resulted in initial annual savings of 11.5t of carbon and when the second phase is implemented, a total reduction of 20t per year has been estimated.

Greater controllability

In-keeping with our GreenTech philosophy, we made advancements to our variable speed EC fans, enabling them to be controlled and monitored remotely. These developments have enabled end users to quickly and easily change the speed of the fans based on their needs, or the information from sensors and monitors.

In one case, we created a customised, stand-alone system that had fan alarm monitoring, as well as remote speed control for the FCUs they were upgrading. This allowed the customer to set the speed of individual FCUs, and identify any failures or alarms from a single control box in their facilities office. When they reduced the fan speed by 10%, we calculated an energy consumption saving of approximately 40%.

Longer service life

EC fans have a longer life expectancy than AC fans. Due to the higher efficiency of the EC motors, they run much cooler which increases the bearing life. By replacing the fan component (which may be coming to the end of its life expectancy), the service life of the entire CRAC or AHU unit is increased.

Reduce maintenance costs

Many legacy CRAC and AHU units are fitted with belt driven centrifugal fans and external control electronics. These fans require a lot of space and have high maintenance costs related to wear-and-tear of parts. Often, large, inefficient belt-driven forward curved blowers are used. In comparison, EC centrifugal fans have impressive efficiency and compactness. Running costs and maintenance work are reduced by the simple ‘plug and play’ system which removes the requirement for transmission belts and commissioning. They can deliver overall efficiency in excess of 60%.