Effect of Moisture on Thermal Performance and Energy Efficiency of Buildings with Lightweight Concrete Walls

Panel: Panel 3. Commercial Buildings: Technologies, Design, and Performance Analysis

Authors:
Dariusz Gawin, Technical University of Lodz (Poland)
Jan Kosny, Oak Ridge National Laboratory
André Desjarlais, Oak Ridge National Laboratory

Abstract

The main objective of this paper is to analyze the moisture effect on the steady-state and dynamic thermal performance of residential and commercial buildings located in California when Lightweight Concrete (LC) is applied as a material for wall construction. The thermal conductivity of five types of LC at various moisture contents was measured. Then, the annual record of moisture distribution in a LC wall was generated for California climatic conditions using HMTRA, a sophisticated computer model of coupled heat and moisture transfer in building materials. Based on the simulation results, the monthly average moisture content was calculated for evaluation of effective thermal properties of the LC wall during successive months after building construction. These data were applied to calculate the energy use during the first three years of building service time. A ranch style residential house and a commercial building located in Sacramento, California were analyzed using the DOE 2.1E computer model. For comparison, the annual energy consumption of similar buildings, with the same thermal resistance of the walls but constructed using steel studs and wood frame walls, was calculated. The LC wall house was the most energy efficient, for both residential and commercial buildings.