You may have heard the term “net-zero home” in conversations about sustainability, but what does it actually mean for you as a homeowner? Put simply, a net-zero home produces as much energy as it consumes, by combining energy-efficient building design with a renewable energy source, such as solar panels that harness the power of the sun.
If you’re looking to boost your home’s energy efficiency, but you’re not in a position to go full net-zero right now, don’t despair. There are still plenty of things you can do to reduce your home’s energy footprint and, as a result, bring down your utility bills and create a healthier indoor environment. We spoke with Mike Topitzhofer, a residential building science expert and the national business development manager at Trane, to learn how to go about it.
Benefits of a Net-Zero Home
Keeping the lights on, running appliances 24/7 and blasting the air conditioner add up to more than just hefty power bills. According to the Environmental and Energy Study Institute, buildings account for nearly 40% of carbon dioxide emissions in the U.S. Going net-zero helps reduce harmful emissions by generating energy through clean methods like solar panels and solar water heating, and incorporating energy-saving design principles such as airtight insulation, energy-recovery ventilation, energy-efficient appliances and LED lighting in the design of your home.
Getting your home to net-zero status can be a significant investment, but it’s one that will pay off in the long run. For starters, indoor temperatures are maintained with lower energy usage, which means lower utility bills. In addition, “there’s a really good case to be made that net-zero homes are also healthier homes,” Topitzhofer says. “They’re energy-efficient and they likely follow strict standards. They’re often airtight and do a good job of eliminating uncontrolled airflow. Net-zero homes generally have very efficient ventilation and filtration systems, which can improve indoor air quality and occupant health.”
Get to Know Your Home Energy Footprint
Not all of us have the means to achieve a net-zero home, but there are plenty of ways we can reduce our home energy footprints. As a starting point, it’s helpful to know which appliances and systems of your home are the biggest energy guzzlers — and prioritize investing in energy-efficiency versions accordingly.
“In single-family homes, heating and cooling systems are generally the biggest energy consumers, accounting for around 55% of household energy usage, according to the U.S. Energy Information Administration,” Topitzhofer says. Other home appliances, such as water heaters, laundry machines, stoves, refrigerators and televisions, as well as lights, account for the remaining 45%. So if you’d like to get a step closer to net-zero, it makes sense to invest in energy-efficient heating and cooling systems to significantly reduce consumption.
Choose Energy-Efficient Heating and Cooling Systems
While replacing your entire HVAC system might seem like a major undertaking, it can be a worthwhile investment that can significantly reduce your home’s energy consumption. “You typically get 15 to 20 years of performance from a furnace. If you have an older furnace, it makes sense to upgrade, as today’s heating and cooling systems are a whole lot more efficient,” Topitzhofer says.
You can compare the efficiency of furnaces by checking the AFUE rating; the closer to 100%, the more efficient. With air conditioning units and heat pumps, look for the SEER rating; a score of 16 SEER or higher is considered efficient.
You should also pay attention to heating and cooling systems’ output capacity. “Basic systems have one speed — on or off — while more advanced technology is either two-stage — low or high modes — or variable-capacity. Two stage and variable-speed systems are the most energy-efficient,” Topitzhofer says.
Trane offers highly efficient variable-speed air conditioning systems with SEER ratings as high as 22. When paired with Trane’s communicating thermostat, the air conditioning system automatically adjusts in tiny incremental changes to avoid indoor temperature swings.
You can boost the efficiency of your cooling or heating system further with a variable-speed air handler, which circulates clean, filtered air to every corner of your home. Trane’s variable-speed air-handler is an energy-efficient system designed with refrigerator-style insulation that prevents sweating, condensation and bacteria growth.
Assess Your Building Envelope
Even if you have a top-of-the-line, highly efficient air conditioning system, if all that cool air is escaping through gaps beneath doors or through thin windows, you won’t have an energy-efficient home — or reasonable utility bills. That’s where the building envelope comes in. This term describes all the physical barriers that separate the interior environment of a home from the outside.
Topitzhofer says that assessing and, if necessary, improving your building envelope is a key step toward creating a more energy-efficient home. “Run times for your furnace and air conditioner are directly related to insulation of your home. If you have a leaky building envelope, your systems won’t run efficiently,” he says. “If your house does a good job at keeping outdoor conditions outside and indoor conditions at a comfortable temperature, you don’t need to spend as much energy on heating and cooling.”
Home energy assessments are often conducted by local building science professionals, whom you can find through your utility company. “Have that person poke around and check for things like leaky ductwork and for any gaps in the attic ceiling insulation. They’ll then propose what building envelope improvements can be done,” Topitzhofer says.
Reduce Home Energy Use
If you’re building or renovating, it’s a great time to implement smart design strategies to improve your building envelope and get your home one step closer to net-zero status. Windows are a good place to start and a common weak point in building envelopes of older homes. According to the U.S. Department of Energy’s Energy Saver resource, heat gain and loss through windows is responsible for 25% to 30% of residential heating and cooling energy use. You can reduce this by upgrading to double- or triple-glazed windows to suit your climate or by opting for energy-efficient low-E glass.
Make sure your floors, walls and ceilings are well insulated to stop unwanted heat gain or loss, and install energy-efficient LED lighting throughout your home. In warm climates, shade windows with awnings or strategically placed trees to minimize unwanted heat gain and use energy-saving ceiling fans or an air conditioner set on the lowest setting to keep your home cool on moderate days.
Another easy way to boost your home’s environmental credibility is to switch to “green power.” “Your local energy company may offer an opt-in program for renewable energy sources,” Topitzhofer says.
With most of us spending more time at home, indoor air quality has become a focus. Exposure to airborne allergens such as dust mites, pollen, mold, smoke and pet dander can have a serious impact on your short- and long-term health, particularly if you have asthma or allergies. They can also affect the quality of your sleep, which affects how you feel and perform during the day.
One of the most effective ways to remove harmful allergens from your indoor environment so you’re breathing cleaner air is with a whole-home air purifier, which is an add-on to the central heating and air-conditioning system. Trane’s whole-home air cleaner, for example, removes up to 99.98% of airborne particles, such as dust, pollution, bacteria, viruses, smoke and cooking odors. “Whole-home air cleaners are the most efficient,” Topitzhofer says. “A forced-air system has ductwork that efficiently cools and cleans the air inside the entire house instead of relying on room-by-room devices,” he says.
Other steps you can take to combat indoor air pollution include choosing low- or nontoxic paints and household cleaners and using a mattress cover to boost your bed’s hygiene. “Humidity and carbon dioxide are also factors of indoor air quality,” Topitzhofer says. “Low humidity dries us out and can make us susceptible to getting sick. High humidity [can encourage] mold growth, which can make also us sick. Make sure your house is in that sweet spot — not too low, not too high.”
Making a few small changes to your everyday habits so you’re using less power will help the environment and can make a big difference in your utility bills. Reduce the need for air conditioning by closing your blinds or shutters on hot days. On those searing days when air conditioning is your only option, switch it on before the peak of the heat so it doesn’t have to work as hard, and close off rooms so you’re cooling only those you’re using.
It’s also important to moderate temperatures, whatever the season, Topitzhofer says. “Mid-70s is a common set point in cooling season and upper 60s and low 70s during heating season.” In fact, studies show that setting your air conditioning unit to 78 degrees in summer can save 10 percent in energy costs per year. Consider installing a smart thermostat — a compact, wall-mounted device that automatically adjusts your indoor temperature to suit the conditions so you don’t waste money on over-cooling or over-heating your home.
In addition to heating and cooling, other areas of the home can benefit from automation and mindful habits. You might also look to install sensors on lights in the yard and bathroom so they go on and off automatically, remind the family to switch off lights and turn off appliances at the wall, and upgrade older home appliances in the kitchen and laundry rooms to more energy-efficient models.
“Once you’ve done these things, getting to net-zero is much easier and requires a smaller investment in renewable power to offset your energy from the grid,” Topitzhofer says. “Basically, optimize for energy efficiency first, then look at things like investing in solar.”
More: For more information on how to make your home more energy-efficient, including finding the right heating, cooling and air-filtration systems for your home, visit Trane’s website.
This story was written by the Houzz Sponsored Content team.