Fans are used, across industries, in air handling units, exhaust air units, fresh air units, direct handling units and other any other applications that involve air flow. EC (electronically commutated brushless DC) or BLDC fans are heralded as the next big thing in air movement. Let us examine why and how it is a game-changer.
Technology and Ease of Retrofit
Fan systems have traditionally been driven by induction motors. The EC motor-fan combination displaces the existing motor-drive-belt-fan setup. It is literally as simple as that.
An EC motor runs on direct current. They have permanent magnets that create rotor or stator fields, unlike traditional AC motors which use electromagnets. Coils, commanded by an electronic controller, play the opposing role of stator or rotor fields respectively. The mechanical commutation of a traditional motor is replaced by electronic commutation, making it brushless.
For the EC fans to function with a regular AC supply input, a rectifier is required, which is typically built in.
The retrofitting process is also extremely convenient and there is minimal disruption in activity. Depending on the capacity, the replacement time per fan can be less than half a day. This system can be seamlessly integrated with an existing Building Management System.
The EC fan makes for a far superior and energy efficient system than a traditional AC-based system because:
- The system is designed based on the required cfm and static. In many cases, these parameters can be achieved with a lower motor capacity.
- The DC motors that are being used by many solution providers are on par or more efficient than IE5 motors.
- EC motors also have an almost-flat efficiency curve i.e. they run at over 90% efficiency even at low or varying loads.
- EC motors typically run cooler than regular motors. This results in extended life due to less wear and heating of the motor
- The EC motor system runs on electronic commutation, so it is brushless and brush losses are eliminated.
- The fan is direct-driven so the impeller is directly mounted on the stator. Hence there is no belt wear either.
- An EC motor does not have rotor copper losses or slip losses.
Other additional benefits include:
- They offer better speed control and are not frequency dependant
- The EC fan does not require any inverter or speed controller
- Further operational savings are ensured in an EC motor due to reduced maintenance costs
- Absence of carbon filters means there is no clogging of filters with carbon.
- They are relatively quiet even at low speeds.
Returns and Caveats
EC fans result in at least a 25% savings in energy. In certain cases, savings as high as 60% have been achieved. The technology is simple and greatly reduces the lifecycle cost of fan operations while greatly minimising maintenance efforts and overheads.
The returns and payback period are inversely proportional to the running hours which means that the longer a fan runs, the sooner the investment is recovered.
A word of caution here – separate the product from the solution.
Excellent fans do not equal a successful retrofit
While many companies excel at manufacturing, design and integration are not their forte. Indeed, there are many cases of failures or lesser-than-projected savings because of a lack of expertise in these areas. This leads to unfair blame on technology, even though over 5,000 fans have been installed and are working well in the country for the likes of GlaxoSmithkline, Honda, Bajaj, Dr. Reddy’s laboratories, ICICI bank, GMR, Samsung, ITC, etc. Inexperienced and unqualified integrators can wreak havoc and collapse project economics.
If you have a fan system that runs on traditional AC motors, you should definitely consider EC fans.
Energyhive, would be glad to have a discussion over how our reliable and proven contractors. who provide turnkey retrofitting solutions with guarantees, could be of assistance to you.