Worth Reading: Spending Through the Roof

Urban Green Council released a report earlier this year addressing the fact that a significant amount of heated air, and therefore money, is lost through openings in the roofs of city buildings, including elevator and stairwell vents. The report – Spending Through the Roof – also offers a selection of solutions for addressing these leakages and reducing utility bills.

New York City Fire Department and New York State regulations have previously required the inclusion of vents at the top of elevator shafts and stairwells in many tall buildings to improve fire safety. These openings, however, can unintentionally serve as black holes allowing the leakage of warm air as it rises up to the top of the building. When this warm air is lost, cold air then enters the building from the outside through the lobby, is then heated, rises, and is lost through the roof once again. Spending through the roof estimates that the amount of heated air wasted each year in NYC alone could fill 29,000 Empire State Buildings, and if not addressed would lead to about 1 million metric tons of Carbon dioxide emissions by 2050. Fortunately, the report provides simple solutions to this impending problem. Building owners can retrofit their buildings by either sealing off two-thirds of each existing vent or installing motorized louvers, depending on the size of the building. The report provides a guide for assessing a building’s potential energy savings based on height, wind exposure, existing vent size, the building envelope type, and outdoor temperature. The Urban Green Council also provides a simple questionnaire to help walk through this process.

The report presents a normalized metric for energy impact, based on the correlation between the calculated seasonal energy impact of the vents and a variety of building characteristics, which helps buildings owners quickly assess savings potential in closing up the vents on any building. New York is one of the pioneering U.S. cities that require energy benchmarking and it is important that building owners/managers stay informed about opportunities to reduce both environmental and financial costs. This report represents a great resource for those interested in making progress in both areas.