Energy Efficiency
What is Energy Efficiency & Why Does it Matter?
At the heart of every household lies a powerful opportunity to embrace residential energy efficiency. Efficiency in this case refers to the ratio of useful work produced to input work required. We ask, “How can we do the same job with less?” But what exactly does this term mean for the average resident? Let’s break it down.
Residential energy-efficiency refers to the practices and technologies that allow a home to use less energy while still meeting the needs of occupants. We can think of an efficient home whose high-performing envelope allows it to require less energy to stay comfortable. We also can think of efficient systems and technologies that, while operating, can accomplish the same tasks using less. This spectrum of efficiency strategies involves everything from better insulation and high-efficiency appliances to smart thermostats and energy-efficient lighting. Benefits of improved energy-efficiency include:
- Combating Climate Change: By reducing energy consumption, residential energy-efficiency plays a crucial role in the fight against climate change. When homes use less energy, they produce fewer greenhouse gas emissions, helping to mitigate the impacts of global warming.
- Electrification Readiness: As society moves towards electrification to power homes and transportation, improving residential energy-efficiency becomes increasingly important. Energy-efficient homes are better prepared to handle the transition to electric heating, cooling, and cooking appliances, reducing reliance on fossil fuels and facilitating the integration of renewable energy sources into the grid. By optimizing energy use now, homeowners can seamlessly transition to a cleaner, electrified future, contributing to overall energy resilience and sustainability.
- Low to no cost improvements: Behaviors such as closing window coverings on sunny or windy days, turning up or down your thermostat 1 to 2 degrees seasonally, utilization of smart power strips for electronics, and sealing doors and windows with weatherstripping, can improve your home’s efficiency.
- Comfort: Improved insulation and better-sealed windows and doors not only reduce energy waste but also enhance indoor comfort. You’ll experience fewer drafts and more consistent temperatures throughout your home, ensuring a cozy living environment year-round.
- Health and Safety: Energy-efficient homes often have better indoor air quality thanks to proper ventilation systems and fewer pollutants entering from outside. This translates to a healthier living space, reducing the risk of respiratory issues and other health concerns associated with poor indoor air quality.
- Affordability: Investing in residential energy-efficiency isn’t just about saving the planet—it’s also about saving money. By using less energy, homeowners can lower their utility bills, freeing up funds for other necessities or leisure activities. Additionally, many governments offer incentives and rebates for energy-efficient upgrades, making them even more financially appealing.
Typical Energy Efficiency Improvements
Insulation
Insulating your home is like wrapping it in a cozy blanket, protecting it from
the
extremes of weather while maintaining a comfortable interior temperature. But
what
exactly does home insulation entail, and how does it work?
Home insulation is a barrier that helps to regulate the flow of heat between the
interior and exterior of a house. By minimizing heat transfer, insulation keeps
your
home warmer in the winter and cooler in the summer, reducing the need for
excessive
heating or cooling.
- Improved Comfort: Proper insulation creates a more consistent indoor temperature, reducing hot and cold spots throughout the home.
- Energy Savings: By reducing the need for heating and cooling, home insulation lowers energy bills and saves money in the long run.
- Noise Reduction: Insulation also provides a barrier against outdoor noise, creating a quieter and more peaceful living environment.
- Environmental Impact: Using less energy for heating and cooling reduces greenhouse gas emissions associated with energy production, contributing to a healthier planet.
There are many areas of a home that could be insulated. Not every home needs, or has the ability, to insulate all of these areas, but it’s good to understand where the opportunities lie.
- Attic Insulation: The attic is often a primary area for heat loss in homes. Insulating the attic floor or roof rafters with materials like fiberglass batts, cellulose, or spray foam can significantly reduce energy waste and improve overall comfort.
- Wall Insulation: Walls can also contribute to heat loss, especially in older homes with inadequate insulation. Common methods of wall insulation include blown-in cellulose or fiberglass, foam board insulation, or insulating sheathing applied during construction or renovation.
- Floor Insulation: Insulating the floors above unconditioned spaces like crawl spaces or basements helps prevent heat from escaping through the floorboards. Materials such as rigid foam insulation or spray foam can be installed between floor joists to minimize the transfer of heat.
- Crawl Space/Basement Insulation: Uninsulated crawl spaces and basements can allow cold air to infiltrate the home, leading to higher heating costs and potential moisture issues. Insulating crawl space walls or basement walls with foam board insulation or spray foam can help maintain a more consistent indoor temperature.
- Window and Door Insulation: Though not traditional insulation methods, sealing gaps around windows and doors with weatherstripping or caulking is essential for preventing drafts and improving energy-efficiency. Additionally, installing double-pane or triple-pane windows with low-emissivity (low-e) coatings provides further insulation benefits. Note – although we are often led to believe that replacing windows is a major driver of energy-efficiency, it can be very expensive to do so, and compared to other efficiency improvements replacing windows typically offers a relatively low return on investment.
- Duct Insulation: In homes with forced-air heating and cooling systems, insulating ductwork helps prevent energy loss as air travels through the ducts. Wrapping ducts in insulation material or sealing leaks with duct mastic or foil tape can improve system efficiency and comfort.
Air Sealing
Just like insulation, air sealing is a key component of creating an energy-efficient and comfortable home. But what exactly does air sealing entail, and how does it contribute to a healthier living environment?
Air sealing involves identifying and sealing any gaps, cracks, or openings in the home’s exterior envelope to prevent uncontrolled airflow between the interior and exterior spaces. By minimizing air leaks, air sealing helps maintain consistent indoor temperatures and improves energy-efficiency. Specific benefits of air sealing include:
- Affordability: By reducing air leaks, home air sealing lowers the workload on heating and cooling systems, leading to lower energy bills and increased energy savings.
- Enhanced Comfort: Minimizing drafts and temperature fluctuations creates a more comfortable indoor environment year-round.
- Improved Indoor Air Quality: Air sealing helps prevent outdoor pollutants, allergens, and moisture from entering the home, improving indoor air quality and promoting a healthier living environment.
- Reduced Environmental Impact: Using less energy for heating and cooling reduces greenhouse gas emissions associated with energy production, contributing to a more sustainable lifestyle.
- Weatherstripping: Installing weatherstripping around doors and windows creates a tight seal, preventing drafts and air leaks. Weatherstripping comes in various materials, including foam, rubber, and vinyl, and can be easily applied to existing door and window frames.
- Caulking: Applying caulk to gaps and cracks in walls, ceilings, and around plumbing fixtures helps seal air leaks and prevent moisture infiltration. Silicone or latex-based caulks are commonly used for indoor applications, while more durable options, such as polyurethane, are suitable for outdoor use.
- Expanding Foam Sealant: Expanding foam sealant is ideal for sealing larger gaps and penetrations, such as around pipes, electrical outlets, and HVAC ducts. The foam expands to fill voids and hardens to create an airtight seal, effectively blocking air leakage.
- Sealing Ductwork: Leaky ducts can waste a significant amount of conditioned air, reducing HVAC system efficiency and indoor comfort. Sealing duct seams and connections with duct mastic or foil tape helps prevent air leaks and improve overall system performance.
- Insulating Foam Gaskets: Installing foam gaskets behind electrical outlets, switch plates, and can lights helps to reduce airflow between interior walls and the outdoors. These inexpensive gaskets create a tight seal around electrical boxes, minimizing drafts and improving energy-efficiency.
Note on Safety: There is a common concern about making one’s home “too tight”. Though the presence of indoor pollutants should certainly be addressed before any air sealing is done, it is difficult and rare to make a home too airtight. When very high levels of air sealing are achieved, mechanical ventilation is the optimal method for bringing in fresh outdoor air in a controlled manner. Uncontrolled air infiltration is a source of energy waste and can present its own health hazards (e.g. air passing through insulation). If mechanical ventilation is, in fact, necessary (which is rare), energy recovery ventilation (ERV) is a good energy-efficient option over a conventional system.
Appliances
Above, we discussed how static characteristics of a home’s envelope (air-tightness and level of insulation) make it a more efficient home, meaning it requires less energy to maintain the same level of indoor comfort. But what about the active systems we still need to operate in order to heat, cool, and perform other basic tasks? All appliances can be measured by their efficiency, a metric typically expressed as a percentage, quantifying useful energy produced compared to input energy required. Appliances (e.g., refrigerators, furnaces, water heaters, etc.) typically have a listed “nameplate” efficiency marked somewhere on the unit’s label or sticker. Though this efficiency might be accurate when the unit is new, the actual performing efficiency can degrade over time. For example, a furnace installed 15 years ago may have once operated at 85% efficiency, but due to wear and tear, now operates at 60% efficiency, consuming more and costing more to accomplish the same job.
So, Though it may seem logical to upgrade some natural gas appliances (e.g., furnaces, boilers, hot water heaters, etc.) to more efficient newer units, we are proposing a phase-out of natural gas appliances in favor of all-electric appliances. This also will ensure improved air quality and the overall health and safety of your home. Electric heating and cooling systems, when used within an efficient home envelope, can accomplish the same job as their fossil-fuel counterparts with less energy. And as the electric grid continues to transition to renewable energy sources, all-electric homes will be able to power themselves efficiently and cleanly. More specific details on all-electric appliances and their efficiency can be found on the Electrification page of this site.
Don’t forget about that old beverage refrigerator in the garage or basement. Though it may seem environmentally friendly to hold onto those appliances, it’s probably worth replacing them with more energy-efficient models, or determining whether they are still of use. DTE Energy will even come pick up and recycle your old one appropriately – and offer financial incentives as a reward for doing so!
Other Equipment
Tips for Finding Energy-Efficiency Contractors
- Insulation
- Air Sealing
- Weatherization
- Building Performance
- Contractors will likely want to come in and do their own assessment of the home, possibly performing their own blower door test (a blower door test uses special equipment to measure the exact amount of air leakage in your home).