City Hyde Park Thermal Balcony Study

Studio Gang Architects commissioned Cyclone Energy Group to lead the research efforts in evaluating the balcony thermal break system impact using one of their building designs as a testing ground. Balcony thermal breaks, which reduce the negative effect of envelope thermal bridges, is a common energy-efficiency strategy in Europe and Canada but is new in the United States market. The goal of this research study was to understand the magnitude of the thermal bridging problem and to evaluate whether balcony thermal breaks are an effective solution to improve building envelope performance. Thermal sensors were installed in the control and thermally-broken balconies and floor slabs of City Hyde Park Residences, a 14-story residential building designed by Studio Gang in Chicago. Then slab temperatures and weather conditions were monitored during a one-year period and later analyzed. The study showed that adding balcony thermal breaks allowed for the improvement of indoor thermal comfort in the residential units. At the same time, balcony thermal breaks allowed increased façade thermal insulation level but by a smaller R-value then what was predicted from the manufacturer’s data. Finally, the energy analysis of the building showed that the addition of balcony thermal breaks can reduce total annual energy usage and cost, but only marginally. Overall, the energy savings with balcony thermal breaks were very small and could not justify the high cost of thermal break product and installation. However, this research study was conducted on a building with the unique architecture and envelope materials, which makes it difficult to make broader generalization on balcony thermal break performance in other buildings. Undoubtedly, the addition of balcony thermal breaks has a potential of improving space thermal comfort and building energy performance but the magnitude of these improvements will greatly depend on the configuration of building parameters.