Cost effective efficiency improvements of building thermal envelopes

Recently, many institutions have aggressively pursued carbon neutrality. Modeling software and other technology has been developed to quantify the carbon production of buildings, due to their large energy consumption. Larger institutions do not always have the technology to monitor individual building\u27s energy use. Indeed, it is difficult to evaluate energy use when the construction and condition of individual buildings is varied. The following methodology provides institutions with a procedure to assess the current energy use of a broad range of buildings as well as possible retrofit planning and their accompanying carbon emission reduction. Building performance analysis assisted in the drafting of the Smith College Climate Action Plan. Seventy-nine Smith College campus buildings were chosen to be analyzed. Buildings that were not included in this study were new structures that are currently being metered, or buildings with unique HVAC systems. Categories were made to effectively model all 79 buildings. These categories were based on the construction type (including wood frame, load bearing masonry or masonry veneer). The current insulation of the buildings was then taken into account within each of the building construction types to develop 11 categories in total. The categories were then modeled, by selecting a representative building from each category, and using a building energy performance software developed by the Department of Energy, EQuest. Details that were inputted into the EQuest software included CAD drawings of the example building, heating and electrical scheduling information, wall details, window specifications, and infiltration rates. Sensitivity analysis was then performed on the following parameters to determine their significance: air infiltration rates, insulation levels in walls and attics, percentage of window coverage of wall surface area, color of the outer walls, and the existence of a basement level. A feasibility analysis was then performed to determine possible retrofitting plans for the college based on payback periods. Current energy consumption rates due to heating loads within the 79 buildings that were analyzed were found to be 72,000 MMBTU/yr. The range of energy use throughout the eleven categories was determined to be 38,000-46,000 BTU/ft2. With proposed retrofit plans of 7 year payback periods or less, the annual thermal energy losses of the college could be reduced to 35% of the current use which would total 47,000 MMBTU/yr. With a more aggressive energy reduction plan, energy performance improvements could reduce the use to 30,000 MMBTU/yr, which equates to a range of 13,000-23,000 BTU/ft2 across building categories