Green Builder Media

I'm an Energy Engineer. This Is How I Set My Thermostat to Optimize Comfort, Energy Efficiency

Written by Michael Siemann, PhD Guest Columnist | Jun 10, 2025 12:54:26 PM

Five Strategies to Keep Your Cool Without Sacrificing Comfort 

Five Ways to Lower your Energy Bill 

As summer temperatures soar, so do energy bills. It’s no surprise: Your home’s cooling system is working overtime to maintain a comfortable indoor climate. Heating and cooling can account for nearly half of a household’s annual energy costs, and optimizing energy use is more important than ever.

Due to increased electric grid demand and rising energy cost to provide that energy, a home's average energy bill is expected to increase across a large portion of the country this year—some areas by as much as 24%. And while you can’t control rising energy prices, the good news is that you can control how and when you use energy.  

1. Use Smart Scheduling  

As an energy scientist, I’ve programmed my downstairs thermostat to follow a six-period schedule to optimize my energy use based on my family’s typical work schedules and activities. I use the recommended pre-set schedules—away, home and sleep—and I add in brief points in time to round out my schedule: 

5:00 AM – Wake: 72°F – Get some cool air moving in the house before I hop on my first call with the team. 

6:00 AM – Morning: 75°F – Let the house coast for a few hours while my solar panels wait for the sun to pass beyond the big tree. 

8:30 AM – Home: 73°F – The sun is shining and powering the house, so I set the thermostat to a comfortable temperature for working from home. 

3:15 PM – Precool: 70°F – Cool down the house while my solar panels are still producing power before the higher energy prices of my TOU rate begin at 4:00 PM. 

4:00 PM – Evening: 74°F – Raise the setpoint slightly to reduce how much expensive energy we need to purchase once the sun goes down. 

12:00 AM – Sleep: 82°F – Increase the setpoint when the downstairs is unoccupied. We stay cool upstairs using a separate mini-split heat pump. 

While this level of detail might seem complex, smart thermostats make it surprisingly easy by automating temperature changes based on a set schedule—either on the device, or with an app.  

2.      Get a Home Energy Audit 

Another great place to begin optimizing your energy use is with a home energy audit. Many utility companies offer audits at a low cost—or even free—to help homeowners identify problem areas and recommend fixes. Whether it’s leaky windows, poor insulation or outdated appliances, an audit can uncover inefficiencies that drive up energy costs. 

3.      Upgrade to a Smart Thermostat 

Maximizing energy efficiency also means using the right features on modern thermostats—or upgrading to a smart thermostat, like our latest smart thermostat, which was named a 2025 Sustainable Product of the Year by Green Builder Magazine. The award reinforces the Honeywell Home brand’s commitment to deliver smart, reliable products that simplify comfort management.

Honeywell Home smart thermostats offer standard scheduling features that allow homeowners to create a daily or weekly temperature plan based on their routines, ensuring that energy isn't wasted when the home is unoccupied.  

In fact, a recent Honeywell Home study* revealed that thermostat users save on average 22% (heating users) and 17% (cooling users) on their HVAC energy consumption when using the recommended scheduling consistently.  

For households with unpredictable schedules, geofencing is another valuable tool. This location-based technology, featured in Honeywell Home smart thermostats, uses your phone’s GPS to detect when you leave or return home, automatically adjusting the thermostat to reduce unnecessary heating or cooling.

If you head out for work in the morning, your thermostat can switch to an energy-saving mode, ensuring you're not over-cooling an empty home. When it detects you're on your way back, it will adjust to your preferred temperature, so your home is comfortable when you arrive. Unlike traditional scheduling, which requires manual programming, geofencing adapts to your lifestyle automatically – even if your routine changes daily. 

For homes with multiple floors or zones, optimizing cooling by occupancy can lead to even greater savings. If you have a two-story house with separate thermostats for upstairs and downstairs, optimizing each zone based on occupancy can drive even greater savings.

For example, during the night, cooling the upstairs where bedrooms are located while allowing the downstairs temperature to rise slightly can cut costs without sacrificing comfort. Similarly, during the day, focusing cooling on frequently used living spaces while raising the setpoint temperatures in unoccupied areas can lead to smarter energy management.  

4.      Be Mindful of Time-of-Use (TOU) Rates 

Another way to save on energy costs is by understanding and taking advantage of Time-of-Use (TOU) rates. My schedule above considers the TOU rates we pay when pulling energy from the grid because many utility companies charge different electricity rates based on the time of day, with peak hours (when demand is highest) costing significantly more than off-peak hours. Typically, electricity rates are highest in the late afternoon and early evening, when air conditioners, appliances and electronics are all in use at the same time.

By shifting energy-intensive activities—like running the dishwasher, doing laundry or charging an electric vehicle—to off-peak hours, you can reduce usage when electricity is most expensive and lower your overall bill. The same applies to cooling your home. If you can precool your home before peak pricing begins—by setting your thermostat a few degrees lower in advance—allows you to use less electricity when rates are highest, you can maintain comfort while using less expensive energy. 

Smart thermostats can help optimize energy use under TOU plans. Many smart thermostats allow you to set temperature schedules that align with your utility's rate structure, automatically adjusting cooling levels to take advantage of lower-cost electricity. If you’re unsure whether your utility provider offers TOU pricing, check with them directly. Many companies offer online tools or apps to help customers track rates and find the best times to use energy efficiently. 

Now, understanding TOU rates is one thing. Applying them effectively is another. While a simple approach, such as shifting some cooling to off-peak hours and reducing energy use when prices spike, can lead to savings, customizing a TOU schedule based on your household’s specific needs can make an even bigger impact. Factors like work schedules, the insulation in your walls, solar energy production and fluctuating electricity prices all play a role in determining the best cooling plan for your home. 

5.      Take Advantage of Demand Response Programs 

Many utility companies also offer demand response programs that help manage the grid demand during peak hours. If enrolled, your smart thermostat can automatically make slight adjustments to your home’s temperature when demand is high, helping to prevent blackouts and grid strain while earning you rebates or bill credits. These minor tweaks have little impact on comfort but can contribute to energy savings and a more reliable energy system. 

Michael on his roof, examining his solar panels


Whether you’re implementing simple scheduling changes or designing a detailed TOU plan, the key is finding a balance that works for you and your home’s unique energy needs. Taking control of your energy use now means a reduced carbon footprint and a smarter, more efficient home and a more comfortable summer, all while keeping costs down. 

To learn more about how you can save energy and on your bill this summer, visit our Resideo Grid Services site. 

*December 2024 Study: Honeywell Home EnergyStar thermostat users save on their HVAC energy costs with use of the scheduling feature. 

 

About Resideo Grid Services 

Resideo Grid Services is a leader in demand response aggregation and program management, helping utilities and energy retailers manage grid demand with precision and efficiency. Since 2012, our team has been providing innovative solutions to reduce peak demand, optimize load flexibility, and support utility programs nationwide. Resideo currently manages or participates in nearly 300 U.S. utility demand management programs and engages in six wholesale energy markets. For more information about Resideo Grid Services, visit ResideoGridServices.com