homes as if they were built to current Maryland codes and standards for low energy use, incorporated existing technology and equipment, and were in the same climate zone as the actual NZERTF. Running the models, the software considered 960,000 building design combinations and eight different economic scenarios to estimate performance over a period of up to 30 years.
Under those criteria, the study results suggest that a natural gas HVAC system is currently more economical overall than an electric one for a code-compliant Maryland home. Although net-zero energy performance was achieved at the lowest cost using electric heating, it came with higher environmental impacts due to the emissions generated during its production.
"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," Webb explained.
However, Kneifel said that electric may yet become the better bargain and more eco-friendly option.
"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," he explained. "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 NIST team members acknowledge that their sustainability study was limited in terms of the equipment type, occupant energy demand and location. They urge other organizations to continue and expand their research to consider several key variables. These include the use of alternative equipment such as ground-source heat exchangers and high-velocity HVAC systems, cost and performance in a variety of climates, and differences in building operation that can affect energy consumption rates. Most importantly, they said that future studies must account for improvements in technology, construction materials and methods, and energy production and transmission.
0 comments:
Post a Comment