Researchers at the National Institute of Standards and Technology (NIST) have compared the environmental impact and energy demand of gas versus electric heating, ventilation and air conditioning (HVAC) systems. For an energy-efficient residential home, the study suggests that gas is the most eco-friendly option.
“Fuel type is an important factor because heating and cooling accounts for a significant amount of home energy consumption,” said study co-author and NIST civil engineer David Webb. “However, little research has been conducted looking at the impact of which fuel source is used, gas or electric, on achieving low-energy and low-impact goals.”
“We used a unique NIST tool set of databases and software known as BIRDS (Building Industry Reporting and Design for Sustainability) to assess and measure that impact scientifically, and then provide a research method for others to do the same for any climate region in the United States.”
The study was focused on data available in the latest version of BIRDS. These measurements were obtained from ongoing research at the Net-Zero Energy Residential Test Facility (NZERTF), which is located on the NIST campus in Gaithersburg, Maryland.
The NZERTF is actually a lab where NIST researchers and industry partners are designing net-zero homes. The researchers used a computer model to create one home based on this net-zero concept that used an electric HVAC system and a twin home that used natural gas.
“This allowed us to make a true apples-to-apples comparison of gas versus electric for their respective energy, environmental and economic impacts,” said study co-author Joshua Kneifel.
The models simulated 960,000 building design combinations and eight different economic scenarios to estimate performance over a 30-year period. The analysis revealed that a natural gas HVAC system is currently more economical for a code-compliant residential home in Maryland.
“The overall economic benefit of natural gas was expected because, at this time, it is the cheaper fuel source in Maryland, costs less in dollars and energy expended to produce and transport, and carries a lower construction price for installation of an HVAC system which uses it,” said Webb.
According to Kneifel, however, electric may become the better bargain and the more environmentally responsible option in the near future.
“For example, as more power companies move to cleaner forms of electric generation, such as natural gas instead of coal, the environmental impact will lessen. Also, technology changes, such as cheaper and more efficient solar energy and HVAC systems, should help make the use of electricity more cost-effective.”
The study is published in the Journal of Building Engineering.
Image Credit: Beamie Young/NIST