Abstract
An alliance to maximize energy efficiency and cost-effective residential construction (ZEBRAlliance) built and field tested four homes that are 50 percent more energy efficient than a code compliant home. The homes are unoccupied for the duration of a two-year field study, thereby eliminating the confounding issue of occupancy habits. All homes have about the same consistent and scheduled internal load. Each home showcases a unique envelope strategy: 1) structural insulated panel (SIP), 2) optimal value wall framing (OVF), 3) advanced framing featuring the benefits of insulations mixed with phase change materials (PCM), and 4) an exterior insulation and finish system (EIFS). All homes have different weather resistive barriers (WRBs) and/or air barriers to limit air and moisture infiltration. Three homes provide space conditioning and water heating via a ground loop heat exchanger, while the fourth home uses a high efficiency air-to-air heat pump and heat pump water heater. Field performance and results of EnergyPlus V7.0 benchmarks were made for roof and attics as compared to cathedral design and for wall heat flows to validate models. The moisture content of the wall sheathing is shown to prove the protecting effectiveness of WRBs. Temperature distributions through insulations in the wall and ceiling with and without PCMs are described to characterize the performance of the PCM building envelopes.
