Detailed energy saving performance analyses on thermal mass walls demonstrated in a zero energy house

• Published in: Energy and buildings Vol. 41; no. 3; pp. 303 - 310
• Main Authors: Zhu, L., Hurt, R., Correia, D., Boehm, R.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.03.2009; Elsevier
• Subjects: Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Dynamic performance; Energy management and energy conservation in building; Environmental engineering; Exact sciences and technology; Heat transfer; Modeling; Simulation; Thermal mass; Dynamic performance; Simulation; Modeling; Thermal mass; Heat transfer; Performance evaluation; Energy analysis; Buildings; Building insulation; Zero energy house; Building wall; Concrete construction; Season; Comparative study
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2008.10.003

An insulated concrete wall system 1 1 T-Mass™ by the Dow Chemical Company. was used on exterior walls of a zero energy house. Its thermal functions were investigated using actual data in comparison to a conventional wood frame system. The internal wall temperature of massive systems changes more slowly than the conventional wall constructions, leading to a more stable indoor temperature. The Energy10 simulated equivalent R-value and DBMS of the mass walls under actual climate conditions are, respectively, 6.98 (m 2 °C)/W and 3.39. However, the simulated heating energy use was much lower for the massive walls while the cooling load was a little higher. Further investigation on the heat flux indicates that the heat actually is transferred inside all day and night, which results in a higher cooling energy consumption. A one-dimensional model further verified these analyses, and the calculated results are in good agreement with the actual data. We conclude that the thermal mass wall does have the ability to store heat during the daytime and release it back at night, but in desert climates with high 24-h ambient temperature and intense sunlight, more heat will be stored than can be transferred back outside at night. As a result, an increased cooling energy will be required.