Phase-Change Frame Walls (PCFWs) for On-Peak Demand Reduction and Energy Conservation in Residential Buildings: Development, Construction and Evaluation

摘要

The main purpose of this work was to develop athermally enhanced frame wall that would reducepeak load air conditioning demand, shift a portion ofthe thermal load, and conserve energy in residentialbuildings. A frame wall containing macroencapsulatedphase-change materials (PCMs),incorporated therein, was developed, constructed, andevaluated. This prototype wall is referred to as -phase-change frame wall (PCFW). A PCFW is atypical frame wall, consisting of outside siding,thermal insulation, studs, and inside sheathing, inwhich PCMs are incorporated, by macroencapsulation,to enhance the energy storagecapabilities of the wall, and thus thermal mass of thebuilding, via the high latent heat of fusion of thePCMs. The PCFW uses off-the-shelf components,which are herein integrated in an innovative way toproduce better energy performance. Results fromfield testing show that the PCFW offers the potentialto reduce wall peak heat flux by as much as 38%.This value is dependent on climate, wall orientation,quantity of PCM, and wall insulation level. Over aperiod of days, the average wall peak heat fluxreduction was approximately 15% when PCFWsfacing four cardinal directions (i.e., N, S, E, W) wereevaluated when 10% 1 concentration of PCM wasused and approximately 9% when 20% PCMconcentration was used. The average space-coolingload was reduced by approximately 8.6% when 10%PCM was applied and 10.8% when 20% was used.The level of fiberglass insulation in the PCFW wasR-11 (1.94 m2K/W). Although frame wall technologywas used as a structural vehicle for this project, theconcept could also be applied in almost any buildingstructure, including structural insulated panels, andconcrete and masonry buildings. The applicationcould also be extended to commercial buildings.