Do You Need Variable Speed HVAC Equipment?

When it’s time to purchase or replace HVAC equipment, it can be a difficult decision choosing which one to invest in. The “bells and whistles” that vary throughout the different options can leave your head spinning; all you really worry about is the bottom line.

Sure, cost is a major concern upfront. But good HVAC equipment can last for years, even decades. It’s not something to skimp on now, only to pay the price in exorbitant energy costs every month for years to come.
When high efficiency is of top concern, one option your contractor may offer you is variable speed technology.
To understand how variable speed technology works, think of how a car operates.
Imagine having a car with one speed – it’s either on or off. Your only option is to run it at full speed, or you turn it off.
Without having an accelerator to control how fast you are going, it would be hard to maneuver throughout your neighborhood. You wouldn’t have the ability to slow down around corners, or speed up when you have nothing but road in front of you.
Variable speed brings the same concept to your HVAC equipment. It gives the system the ability to match the actual load. It can speed up or slow down, depending on the requirements of the system.
Variable speed impacts both energy savings and comfort levels. By varying the speed, systems are better able to match load in both heating and air conditioning needs.
With HVAC equipment, the words variable speed can apply to HVAC equipment in three distinct ways.
1. On system return/supply fans
This is considered a retrofit on existing equipment already in place. Many major manufacturers apply variable frequency drives to their return or supply fans in order to realize savings. In this context, variable speed refers  to the ability to match fan speed and therefore air volume to the corresponding load on the system.
2. On fixed capacity compressors
Several compressor manufacturers allow the use of variable frequency drives with a fixed capacity compressor. Although this approach is not considered to be a pure form of variable speed technology, it can increase efficiency and as such can offer benefits in certain aspects.
3. With dedicated variable speed compressors
This is the truest form of variable speed. The compressor is designed where the speed of the motor depends directly on the frequency applied. Each compressor is paired and optimized with a variable frequency drive that provides smooth, uniform rotation no matter what the speed.


If efficiency and energy savings are at the top of your to-do list this year, considering variable speed technology may be the best way to help achieve your goals. If you have any questions, we’re here to help.

Recent Blog Posts