Three ways to optimize your AC use
By Andrew More, Director of Business Development - May 05, 2022
Ensuring your air conditioning (AC) system is up-to-date will save money and cut emissions.
Businesses are on the lookout for energy savings and AC optimization is a good place to start.
Savings opportunities range from optimizing temperature settings to installing building automation systems.
Agile companies can reduce AC-related costs and maintain occupant comfort at the same time.
This summer, more businesses will be feeling the heat. Rising energy prices and global temperatures are challenging companies to reduce costs without hurting occupant comfort.
Balancing comfort and cost cutting is a fine line for building managers, but there are ways to do both, particularly when it comes to AC. From simple temperature changes to installing smart sensors, optimizing AC systems can save you tens of thousands of dollars.
AC demand is only going up
Climate change is leading to more extreme weather events, including heat waves. As more people turn on the AC, the demand on the grid goes up. This leads to more severe electricity peaks and emphasizes the need to minimize wasted energy in our AC systems.
Peak pricing is expensive, so building managers need to find ways to reduce their energy demand. A good place to start is optimizing HVAC systems, which on average comprise 40 percent of a commercial building’s total electricity consumption.
Building managers can be hesitant to compromise the comfort of occupants. For this reason, energy efficiency often takes a backseat, leading to significant costs from poorly-optimized AC systems.
Inefficient AC systems cost businesses by increasing electricity demand, peak prices, and carbon pricing payments. Fortunately, AC optimization can mitigate these costs, either through upgrades or by changing the way the system responds to these events.
1. Automating stop-start settings
One way to improve AC optimization is to use automated stop-start functions. To do this, businesses can employ a building management system (BMS). This lets them tailor their energy management, instead of relying on a default cooling schedule that doesn’t suit their needs.
BMSes use self-adaptive algorithms that monitor occupancy and connect to building schedules, improving efficiency and cutting costs.
For example, optimizing stop-start times can finetune a building’s cooling period based on how it reacts thermally during the day.
Optimizing AC systems can save you tens of thousands of dollars.
Consider an office building with an annual energy demand of 2,500 megawatt hours (MWh), where the HVAC system uses 70% of building base electricity supply.
After analyzing building usage, the BMS changes the cooling period to 7:45 am – 5:15 pm (instead of 6 am – 5:30 pm). This two hour reduction saw energy savings of 12 percent.
This works out to energy savings of 210 MWh per year. At a price of $0.10 per kilowatt hour (kWh), this one move saves $21,100 each year.
Performing these tasks without automation means a lot of work for a building’s energy manager (if the building has one). Otherwise, someone has to remember to constantly check temperatures and manually alter settings on a regular basis.
Running around a facility to turn dials is unrealistic; it wastes time and is expensive, especially if energy use is not reduced effectively during peak hours.
2. Increasing the distance between temperature set points
Another easy change that makes a big difference is increasing the distance between temperature set points. In other words, optimizing the AC to stay off longer and kick in at a higher temperature reduces energy use. And combining a wider temperature band with the aforementioned reduction in operating time is a great way to save even more.
While maintaining occupant comfort is important, we all experience “adaptive comfort” — our comfort range shifts seasonally as we acclimatize.
Even an increase of 1°C (e.g. cooling starting at 24°C instead of 23°C) can reduce electricity use by 10 percent.
Let’s use another example to demonstrate savings. A 20,000 square meter office building uses 3,000 MWh each year. The HVAC system uses 70 percent of total base demand, of which the chillers comprise 25 percent. The heating kicks in at 20.5°C, cooling starts at 24.5°C, and the building’s set temperature is 22.5C°C.
With this setup, the building's chillers use 20 percent less energy (105 MWh annually) compared to a 21°C to 23°C range. This leads to savings of $10,500 per year, assuming an electricity price of $0.10 per kWh.
3. Tweaking fan settings
Businesses can further improve AC efficiency by tweaking the settings for their air handling and condenser fans. Resetting duct static pressure on a regular basis can reduce the energy demand of air handling fans by up to 30 percent. This is because the fixed static pressure is usually set too high due to over-conservative margins designed around handling extreme loads.
For condenser fans, installing variable speed drives will provide significant energy savings by allowing you to finetune head pressure. Specifically, instead of a wasteful on-off fan cycle, variable pressure control helps energy users prevent overcooling and over-condensing of the AC system.
These AC improvements work best when utilized as part of a BMS, which can automatically adjust usage to cut costs and emissions. And to maximize savings, businesses can empower smart, responsive cleantech solutions to react to market price signals, and reduce usage during peak hours.
Optimizing AC systems generates significant savings, but many companies are either unaware of these savings opportunities, or do not have enough capital to pay for them.
How EnPowered can help lower AC costs and drive sales
As solution providers know, funding hurdles derail too many clean technology projects. Record inflation and energy price spikes make businesses even more hesitant to invest.
EnPowered Payments helps solution providers unlock stalled projects by eliminating up-front costs and minimizing customer risk. Payments is an on-bill payments platform that lets customers pay for energy solutions through their electricity bill.
With Payments, customers use a portion of their AC savings to pay for their chosen solution. Once the HVAC solution has been paid off, customers enjoy 100 percent of their savings and an even lower energy bill. With flexible, tailored repayment options, the only question your customers have to ask themselves is — “How much do I want to start saving right away?”
Ready to learn more? Contact us today to discover how Payments can help you unlock stalled projects, and help your customers cut their AC costs and emissions.