Energy consumption in buildings accounts for 41% of Utah’s total energy consumption. Improving the energy efficiency of new homes will directly benefit Utah’s air quality. This reduced air pollution comes largely from reduced natural gas combustion and reduce demand for electricity due to more efficient building envelopes, such as improved wall and ceiling insulation values and reduced air leakage. These improvements provide ongoing energy savings and reduced air pollution for the 50- to 100-year life of the home.
In the coming decades, most new homes in Utah will be built in counties that are currently listed as areas “non-attainment” for National Ambient Air Quality Standards. Importantly, the direct pollution reductions associated with natural gas combustion will also take place within these counties.
According to the Utah Division of Air Quality[1] “Area” source emissions (from homes and buildings) accounted for 39% of the total emissions during an average winter day in 2014 (an increase from 32% in 2008). Hence, the emission reductions from adoption of 2015 IECC are important to help improve Utah’s poor air quality. The emission savings from reduced natural gas consumption in all new homes built between 2020 and 2040 is estimated to be 4,917,486 pounds or 2,231metric tons cumulatively by 2040.
Emissions reductions from electricity generation are expected to be over 27 million pounds or 12,413 metric tons cumulatively by 2040.
The primary air pollutant reduced from more efficient use of natural gas is nitrogen oxides (NOx). Other emissions reduced are volatile organic compounds (VOCs), direct particulate matter (PM), and smaller amounts of sulfur dioxide (SO2), and nitrous oxide (N2O).
The primary air pollutants reduced from reduced electricity generation are sulfur dioxide (SO2) and nitrogen oxides (NOx).
NOTES:
- Additional emissions reductions result from improved efficiency in commercial buildings, but were not analyzed in this study.
- Estimates are based on the BCAP energy code calculator using data from U.S. Energy Information Administration and U.S. Census data.
- Emissions data is based on natural gas combustion emission factors from U.S. Environmental Protection Agency’s Compilation of Air Pollutant Emission Factors, AP 42., Fifth Edition, Volume I, Chapter 1: External Combustion Sources (1998), Table 1.4-1 and Table 1.4-2, URL: http://www.epa.gov/ttn/chief/ap42/ch01/final/c01s04.pdf
- HVAC system efficiency improvements are not included in this analysis, since appliance standards are not set by building codes. Including HVAC system efficiency improvements would reduce air emissions further.
[1] Utah Division of Air Quality presentation to Utah Clean Air Action Team (July, 2014)