Upgrading one component in an HVAC system could reduce a building's energy use by 40 per cent. Helen McHugh discusses the benefits of upgrading only the fan component of an HVAC system to an EC (electronically commutated) motor.
04 April 2018 | Helen McHugh
HVAC systems are typically responsible for 60 per cent of a building's energy consumption, so reducing the energy impact of these units can be rewarding for building, energy, and facilities managers.
One of the simplest ways to reduce energy use in a commercial building is to ensure that 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 directly from single-phase or three-phase mains supplies.
The result is high-performance, silent-speed control and long life expectancy in a product that is the same size as the old power-hungry AC products it replaces.
But it is not always financially viable to upgrade entire HVAC systems to reap the benefits of this improved technology. There are still advantages to 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.
Here are five core benefits of opting for this solution.
1. Energy savings mean cheaper bills
Marks and Spencer achieved energy savings of over £500,000 by upgrading to EC technology. The retailer had 1,404 fans and 258 condensers installed in 152 stores across the UK and Ireland. Following the upgrade, it has achieved an estimated annual energy reduction of 3,265.3kWh per fan, equalling savings of £375.51 per fan and annual savings of £527,223.
2. Reduced carbon emissions
Through the Climate Change Act 2008, the UK Parliament aims to reduce the UK's greenhouse gas emissions by at least 80 per cent (from the 1990 baseline) by 2050.
The Scottish Parliament has also upgraded its HVAC equipment to EC fans, resulting in initial annual savings of 11.5 tonnes of carbon and an estimated total reduction of 20 tonnes.
3. Increased controllability
Variable-speed EC fans allow can be controlled and monitored remotely, enabling end users to adjust fan speed according to their physical needs or relayed information from sensors and monitors.
Through the use of fan alarm monitoring and remote control of fan coil units (FCUs), the speed of individual FCUs can be adjusted while any failures or alarms can be responded to from a single control box located in a facilities office. Reducing the fan speed by 10 per cent can lead to 40 per cent reduced energy consumption.
4. 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.
5. Reduced maintenance costs
Most 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 need for transmission belts and commissioning. They can deliver overall efficiency of over 60 per cent.
Helen McHugh is head of new product research at fan and motor part manufacturer ebm-papst