Leadership in Energy and Environmental Design (LEED) is currently the most widely used rating system for green building in the world. As per the U.S. Green Building Council (USGBC), LEED certification sets the standard for healthy and highly efficient homes and buildings. According to the United States Department of Energy (DOE), LEED-certified homes use 20% to 30% less energy than homes that lack this distinction. LEED-certified commercial properties use even less. Whether you’re purchasing a LEED-certified property in Sacramento, CA or designing one, the following is everything you need to know about the role of HVAC.
What Are the Primary Goals of LEED Certification?
Fortunately for building residents, LEED certification denotes far more than efficient, environmentally friendly design. Among the overarching goals of LEED and the related certification program are:
- Creating healthier indoor environments
- Promoting site sustainability
- Allowing for easier integration and upgrades
- Ensuring ease-of-use and overall convenience
While LEED certification leads to lower carbon footprints, less landfill waste, and other important environmental gains, it also makes living in, working in, and using buildings far more enjoyable overall.
Why HVAC Systems Play an Important Role in Green Development
In both residential and commercial buildings, heating and cooling costs often account for about half of the typical energy bill. This is especially true during times of temperature extremes. Installing high-performing heating and cooling equipment minimizes both energy consumption and spending.
Some heating systems such as electric furnaces boast annual fuel utilization efficiency (AFUE) ratings of 100%. These units convert all of the electricity they use into heat energy. In the right settings, heat pumps offer efficiency levels of 400% or higher. They produce four times the heating and cooling energy that they consume in electric energy. Installations like these create marked, measurable savings from month to month and over time.
However, efficiency isn’t the only environmentally friendly attribute that HVAC systems need to qualify properties for LEED certification. This rating system also accounts for the environmental impact of HVAC refrigerants, construction materials, and the output of emissions like carbon monoxide (CO). While high-efficiency gas furnaces can boast AFUE ratings of up to 98.5% and only waste about 1.5% of the fuel they consume, poorly combusted fuel is still released into the natural environment as greenhouse emissions. At a time when nations, states, and small municipalities are implementing ambitious “zero emissions” plans, even this seemingly nominal output matters.
Climate Control
HVAC systems in LEED-certified homes offer optimum climate control. For ducted, central HVAC systems, this means creating a single, uniform temperature throughout buildings without hot and cold spots and without drafts or heat losses due to poor building envelopes.
Zoned climate control is an increasingly popular enhancement that divides buildings into separate service areas. With zoned heating and cooling, there’s no need to heat or cool unoccupied spaces. Moreover, building residents or property managers can customize temperatures in individual areas to suit the needs of the environment or personal preferences. Each service area in a zoned HVAC system gets its own smart thermostat, and residents can adjust individual thermostat settings without affecting temperatures in other areas.
Efficiency
Heating and cooling systems in LEED-certified homes come with efficiency upgrades like variable speed motors, secondary heat exchangers, heat recovery ventilators, and hybrid heating systems that fuse efficient furnaces with heat pumps. Efficient HVAC design does more than simply target equipment with the highest efficiency ratings. Many developers use special, energy modeling software to devise strategic heating and cooling plans that optimize airflow and air distribution, support the heat transfer process, leverage good ventilation, and more.
According to the University of Florida, HVAC ducting can lose up to 40% of the heating and cooling energy that HVAC systems produce. Thus, when focusing on efficiency for LEED certification, builders and buyers must consider the efficiency of air ducts. Both aluminum and galvanized steel ducting offer impressive levels of efficiency. However, fiberglass ducting offers efficiency paired with noise reduction. Ducting in LEED-certified properties is also sealed and insulated to further minimize thermal losses.
Improved Indoor Air Quality
LEED-certified buildings have designs that acknowledge the “V” in HVAC. Short for ventilation, this is the most frequently overlooked factor in heating and cooling systems and a critical tool in promoting healthy indoor air.
Older buildings were often naturally ventilated due to loose envelopes and minor gaps and cracks in building materials. These openings allowed stagnant and toxin-addled indoor air to flow out while bringing fresh, outdoor air in. Also known as air exchange, this automatic and ongoing process removed many gaseous, chemical contaminants from building interiors, such as benzene, formaldehyde, and other off-gassed volatile organic compounds (VOCs).
However, both LEED-certified properties and standard buildings built for efficiency have increasingly tight envelopes. Tightening building envelopes prevents heat loss during the winter months and unwanted heat gains in summer. To achieve the perfect balance between air exchange and envelope tightness, LEED-certified properties often incorporate various forms of mechanical ventilation, such as energy recovery ventilators (ERVs) and heat recovery ventilators (HRVs). Whole-house fans and strategic window selections also increase ventilation while promoting efficiency.
Heat Pump and AC Refrigerants and LEED-Certification
When applying for LEED certification, builders and property owners should target the latest and most cutting-edge AC and heat pump refrigerants. Just as Freon or R-22 has been phased out due to the hydrochlorofluorocarbons (HCFCs) that it contains, its replacement, Puron or R-401a has also been rendered obsolete. R-401a is better for the natural environment than Freon, but it still contains hydrofluorocarbons (HFCs). R-454b or Opteon XL41 is currently the industry standard in environmentally friendly, residential AC refrigerants.
HVAC Control Systems
The addition of smart technologies optimizes the efficiency of HVAC systems and eliminates much of the energy waste that arises from human error and oversight. Zoned central HVAC systems are governed by central controls that receive input from two to four smart thermostats. These systems use call and hold signals to open and close duct dampers and bypass ducts to customize air delivery.
The smart technologies that support zoned HVAC systems offer features and functions like:
- Energy tracking
- Real-time indoor air quality monitoring
- Reminders for filter changes and equipment maintenance
- Remote functionality
- Geofencing
With smart thermostats, homeowners and property managers can access and adjust these Wi-Fi-enabled devices using tablets, laptops, or mobile phones along with branded apps. This level of functionality allows for the immediate correction of unwanted temperature changes. It also helps consumers identify small and developing problems throughout their HVAC systems before these issues spiral out of control.
Smart thermostats are also learning devices. Not only can you set a smart thermostat to raise or lower your temperature just before you exit the building, go to bed, or come back home, but you can also set your device to track and learn from your schedule and behavior. Over time, smart thermostats become increasingly adept at adjusting themselves.
Geo-fencing integrates HVAC systems and their features with other smart technologies to provide real-time convenience based on residents’ whereabouts, activities, needs, and more. For instance, with geo-fencing, your smart thermostat can make unscheduled temperature adjustments to account for unplanned trips out of the building. This way, if dash off for an emergency, your heater and air conditioner aren’t running non-stop until you return.
Since 2004, we’ve been proudly serving Sacramento, CA and the surrounding cities. You can turn to us for expert heating, cooling, plumbing, and electrical services. We also offer insulation, home electrification, and advanced indoor air quality improvements. To find out more about qualifying your home for LEED certification or to schedule an appointment, contact Huft Home Services today.
