Reducing operating costs is an ongoing goal for commercial facilities. Electrical energy is typically a large expense for businesses, so by decreasing overall energy consumption, they have the potential to achieve long-term savings.
According to the U.S. Energy Information Administration, the three biggest expenditures of energy in commercial buildings are: HVAC (28%), power plug loads (33 percent) and lighting (39 percent). This post will examine the opportunities to create more energy-efficient commercial HVAC systems.
Reducing Energy Use in HVAC Systems
A traditional HVAC system often uses more energy than is needed to manage heating and cooling loads. A mechanical damper controls the amount of airflow used in the system, but the motor still has to run at a constant full speed to support it. The motor can cycle on and off to try to match the load when full power isn’t necessary, but this wears down equipment over time, requiring an increase in repairs and replacements.
A variable frequency drive (sometimes called an adjustable frequency drive), on the other hand, reduces energy use by adjusting a motor’s speed based on the necessary load. HVAC systems that use VFDs don’t need to run electric motors at 100-percent capacity constantly. They are able to control energy use based on need, and they can benefit from lower electrical bills, longer equipment life and decreased maintenance costs.
Energy Savings with Variable Frequency Drives
Variable frequency drives control the speed of the motor by varying electrical voltage and frequency to meet load requirements. The VFD converts AC line power to DC, storing it in a DC capacitor and then converting it back to AC power at the correct frequency.
Due to affinity laws, HVAC systems utilizing VFDs can reduce energy consumption dramatically – by 50 percent or more.
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