HVAC - New controls applied to a single phase HVAC motor reduced energy use by 90%

Challenge: Update a 75-year old school facility with a central HVAC system that has fan coil in each classroom. While providing better temperature control in each classroom was a goal, the major complaint of the faculty and students was the noise generated when running the fan coils, making teaching difficult. There was also no local control of the fan coil units resulting in rooms that were often too hot or too cold.

Analysis: Intellicon personnel were initially brought in to create a custom motor drive control to provide individual fan control in each room. During their preliminary investigation it was determined that many of the classrooms had oversized motors that could be replace with more efficient units.

Results: Working with the contractor, Intellicon engineers recommended downsizing many of the fan motors. In addition, Intellicon provided intelligent motor controllers that allowed for various sensor inputs including variable fan control and motion detection for room occupancy.

Conclusion: The occupants of the classrooms were very pleased with the results. The local fan control allowed for better temperature control and combined with the downsized fan motors eliminated the excessive noise in the classroom. An energy audit also showed that this combination of resizing the fans and adding intelligent reduced energy use by 90%! Energy savings alone allowed the school to pay for this retrofit in less than 6 months.

The Proof:


The 75 year building has had many HVAC upgrades in the past but this is the first to bring modern controls to the individual classrooms.

Each classroom is heated and cooled using a fan coil system.

Design had to take in effect the input power, space and weight restriction of the current fan coil units.


Installation of ¼ HP fan and local controller are key items for optimal temperature control and eliminating fan noise.


Simplicity of use is always a consideration
with HVAC systems. The user simply dials in
the required air flow to heat up or cool down the classroom.

Email: info@intelliconelectronics.com

Tel: 714.751.9257