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So far in our variable frequency drives (VFDs) and HVAC series, we’ve introduced VFDs and explained some of the benefits that they offer. One of the major points Alliance Engineering has underlined with respect to variable frequency drives is how they help save on energy and therefore energy related costs. We’d now like to break down just how impactful VFDs can be in terms of energy reduction by looking at how they streamline your HVAC system as well as some interesting examples and applications!

A simple and data-driven setup

A variable frequency drive setup consists of your power source and motor with a controller and interface. We’ve already talked about how fewer mechanical parts (like additional brakes and valves) reduces unexpected failure chances and the associated cost of fixing or replacing parts. It warrants repeating though, that a streamlined system with fewer big mechanical parts will use less energy overall. Since VFDs are controllers for your motors, they provide you with different options depending on load. The controller monitors and communicates with an interface that can provide site managers and technicians useful information to tweak settings and optimize even further.

So how much energy savings exactly?

Variable frequency drive installations in HVAC systems mean you can reduce the speed of the Stage 1 cooling and ventilation fan by 30% resulting in a reduction of energy usage anywhere from 25% to 70%. The reduction can result in savings that foster a payback cycle of less than a year in some cases. For most current HVAC applications, the use of variable frequency drives means more information, flexibility, reliability, and of course… lower costs. This technology is not just for new units though, older ones can still be retrofitted and have increased lifespans. There’s also the case where a full system replacement may not be a possibility. Variable frequency drives are definitely the more energy efficient and affordable option here!

Energy saving options and applications

The newest models of VFDs are designed for optimum efficiency with lots of energy saving options and components. The drive itself is built with circuitry and an energy saving function optimized to use the least amount of power necessary. There are also aspects like automatic transfer switching, energy-optimized braking, and temperature-controlled fans. At the University of Southern California (USC) campus, VFDs have been used in lots of different energy saving projects including direct digital communication (DDC) technology and VFDs being connected to the AC supply line. The result has been one of success where fans and pumps controlled by variable frequency drives are up to 70% more efficient than those running at a constant speed.


Contact Alliance today to discuss how you can save money by improving the efficiency of your HVAC systems. Our solutions incorporate all available technologies to ensure an energy efficient building with optimal performance. We’ll provide you with options based upon the most effective energy reduction solutions available, including any applicable incentives!