How to reduce energy costs and optimize HVAC unit performance
In the business of facilities management, addressing rising costs and increasing energy efficiency are key goals. One leading national retailer has successfully done both, cutting energy costs up to 28% while simultaneously increasing ROI and lifespan on their rooftop units. How? Read on.
Here’s the challenge: a national large footprint retail chain with a variety of different brand types (offering high-end furniture, household items, specialty goods, and more) has facilities spread across every state. Think multiple locations, each brand with unique floorplans and HVAC performance needs that must be optimized. Find the right way to optimize all stores across all brands and millions of dollars in cumulative savings could be achieved.
The company in question and NexRev partnered together and found a way to do it. The solution has allowed an immediate and lasting savings in energy consumption to be secured. A reduction up to 28% in energy costs accrued alongside reduced system maintenance requirements and better performance from existing units has put the company in a much better position to meet their savings, comfort, and business goals. Let’s look at how that hugely successful outcome was reached.
What to do about HVAC?
Historically, the company had a policy of maintaining and repairing its HVAC units rather than replacing them, at least where possible. A conversation with NexRev persuaded them that the addition of DrivePak™ with Variable Frequency Drives (VFDs) might be a good way of upgrading the unit’s performance and longevity without any need for replacement. Why? DrivePak provided both cost savings through improved control over airflow and humidity and extended equipment life through soft starts and by controlling short cycling.
DrivePak is NexRev’s energy-saving upgrade package for new and existing rooftop air conditioning units found in quantity on nearly all retail, grocery, entertainment, and dining facilities.
Persuaded that the idea made sense in principle (and further attracted by evidence that DrivePak could help improve process control, reduced wear on their machines, and increase measurable energy savings) the company decided to trial NexRev technology in different ASHRAE climate zones to establish a performance benchmark.
So, the company installed DrivePak at the selected sites and tested the performance of multiple HVAC units in each store with DrivePak installed on one unit but not on another. This provided a true “apples to apples” comparison of DrivePak’s impact and, unsurprisingly, the savings were immediately much more apparent in those units that had DrivePak installed.
How the DrivePak solution worked
Why was this the case? DrivePak is able to generate significant energy savings in RTUs by optimizing the relationship between speed and power to deliver substantial energy savings. For example, when a fan’s speed is reduced by just 20%, fan motors experience around 50% energy savings (as described by the Fan Affinity Law). The takeaway here is DrivePak quickly delivers sizeable energy savings and, in turn, benefits the company’s bottom line.
And additional energy savings are also achieved by reducing humidity levels with DrivePak. Lower humidity levels allow thermostats to be set several degrees higher and still achieve optimal comfort. For example, each one-degree increase in the target temperature translates to a three percent reduction in energy use.
You can think of DrivePak™ as an energy-saving upgrade package to any new or existing, standard, rooftop air conditioning units. A modular solution, it works by optimizing HVAC fan speeds to the needs of the local environment, reducing peak demand, and controlling spikes. As this case demonstrated, it can be retrofitted to existing HVAC units, minimizing costs and labor. Also notable is that it’s fully integrated with NexRev’s Freedom cloud-based EMS, connecting remote HVACs from multiple sites into a single, cohesive control center.
Great results
Back to the use case. With DrivePak deployed, significant energy savings from the optimized performance of its rooftop HVAC units were quickly seen by the company and the savings in power usage have helped it to renegotiate utility contract demand rates with multiple energy providers and further reduce energy costs.
Significant benefits have come in high humidity locations because of improved humidity reduction that result from less air needing to be pushed across coils. Overall, the company estimates that installing DrivePak has reduced overall location energy costs by up to 28%. Another benefit is that equipment ROI has increased because asset life span has been extended. With DrivePak, belt replacements are now less frequent due to smoother start up and filter replacements are more infrequent because filters last longer due to better controlled air flow.
And multiple benefits
Retrofitting DrivePak into rooftop units means individual facility HVACs are optimally configured for the specific location’s needs not just factory configured for max climate conditions and operated at a constant blower speed. Units that were underperforming have now become as, if not more, efficient than more modern HVACs.
When you look at the kwh saved, available rebates, and reductions in maintenance costs NexRev estimates that each DrivePak unit returned its investment in less than 18 months. If, as expected, energy prices continue to increase, the ROI will reduce even further.
If you face a similar challenge to the company in question, or your own goal is a proven, measurable approach for upgrading HVAC unit performance that delivers a rapid ROI and you’ve found this blog interesting and a useful starting point for further exploration, why not read the full Case Study behind the story.
What we discussed here is the tip of the iceberg. It contains a great deal more detail on the steps taken and how the key decisions were made. You can find (and download) it here.
About NexRev
At NexRev, we’ve been unlocking the power of facility and energy management data with over a million connected devices across North America. Our team of experts is focused on helping you deliver more with your budgets, infrastructure, and assets to create sustainable savings in operations and energy, reducing your risk and increasing operational confidence.
To begin a discussion on how we can help you to reduce energy waste please email us at