William M. McGinley, and Li Liu,
William M. McGinley, PE, FASTM, FTMS, Professor and Endowed Chair for Infrastructure Research, Dept. of Civil & Environmental Engineering, Louisville, KY, m.mcginley@louisville.edu
Li Liu, Ph.D. Candidate, Dept. of Civil & Environmental Engineering, Louisville, KY, releanlou@gmail.com
ABSTRACT
Both the demand and the cost of energy is increasing as the US population and economy continues to grow. This has prompted more energy efficient buildings to be designed and constructed. Although Energy Code provisions define alternative design methods that can be used to meet the energy efficiency requirements, due to ease of use, most buildings are designed using the
prescriptive approach. The Hawaiian State Building Code recently adopted the 2015 IECC and now prescriptively requires continuous insulation for exterior masonry walls. Although the alternative provisions will allow non-insulated walls to be used, most designers use the IECC prescriptive provisions and thus will likely design exterior masonry walls with prescriptive continuous insulation. These increases in the prescriptive envelope provisions suggest that energy efficient designs must start with increases in the thermal resistance of the building envelope. However, studies have shown that increasing exterior envelope insulation may have only a minimal effect on the overall energy performance of the building, especially for exterior walls with a high thermal mass. A holistic energy study was conducted using a variety of energy conservation measures intended to improve the energy performance of buildings with exterior walls of uninsulated masonry in the Tropical (Hawaiian) climate. Payback analysis were also conducted to evaluate the economic performance of a variety of proposed energy saving strategies. These
analyses suggest that, in general, high reflectance walls are recommended for all buildings in Hawaiian climate and produce buildings with good energy performance.
KEYWORDS: energy analysis, uninsulated exterior masonry walls
