Buildings account for 40 percent of the energy used in the United States and a similar percentage of carbon dioxide emissions.
Engineers at the National Institute of Standards and Technology (NIST) — with its mission to promote U.S. innovation and competitiveness by advancing measurement science, standards, and technology — recently used technology advances on their own facilities to promote energy efficiency. Engineers looked at energy-related upgrades to their own quarters and found energy-related improvements were well worth the expense.
A NIST plan to act on the findings should save taxpayers money and help meet a presidential order for federal agencies to cut energy use by 2015 to 70 percent of 2003 levels.
The NIST researchers undertook their study using two adjacent offices in one of the general-purpose buildings on the NIST campus. The building is typical of those constructed on the campus in the 1960s. One office served as the control office, and NIST modified the second office to reduce the flow of energy through the exterior wall.
Tesearchers carefully monitored each room to determine energy savings that could result from various energy-savings options while maintaining identical levels of comfort.
The unmodified, control office has a one-pane glass window unit and an antiquated heating-and-cooling unit. Thermal insulation was not present between the exterior walls of the office and the interior space. Significant air leakage occurred between the interior of the office and the outdoor air as a result of numerous gaps and voids in the exterior wall.
In the modified office, researchers sealed air leaks, insulated exterior walls with 9 inches of glass-fiber insulation, and replaced a 40-year-old, single-pane glass window with a double-pane, argon-filled, insulated glass window unit.
They also installed a forced-air heating-and-cooling unit in the attic to deliver conditioned air to the office module, replacing the antiquated heating-and-cooling system that required piping in the office module walls. Energy-upgrade costs totaled $2,825.
Measurements made to compare the energy required to maintain the control and modified office modules at identical conditions revealed a 59 percent savings. Annual cost savings from the energy upgrades, based on 2007 energy prices, came to $195 per year.
The researchers used NIST’s Cost Effectiveness Tool for Capital Asset Protection software to figure in a 3 percent escalation rate in annual energy prices. They found that over a 25-year period, the improvements would generate an average savings of $1.75 for each dollar invested.
NIST will begin implementing the research findings in April. In the first phase, 22 offices will be upgraded with the energy-saving features. The remaining 85 offices will be modified in 2009 and 2010.
More information on NIST work to improve building energy efficiency is available at NIST’s Building Environment Division web site.
NIST ’s Cost Effectiveness Tool for Capital Asset Protection Version 3.0 is available for download.
