Monitoring of Internal Moisture Loads in Residential Buildings - Research Design and Early Findings

The U.S. Department of Housing and Urban Development had funded Steven Winter Associates, Inc. (SWA) to collect moisture load data that will support research to better understand the impact of moisture on the durability of homes. Little to no measured data is available on actual indoor humidity levels in U.S. households making it difficult to design durable homes. This research project has collected one full year of indoor temperature and humidity data for a sample of sixty homes across three different climate regions – the hot/humid southeast, cold northeast and marine northwest.

This research is in direct support to the American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc. (ASHRAE) Standard 160, Criteria for Moisture-Control Design Analysis in Buildings. With assistance from Oak Ridge National Laboratory (ORNL) as a subcontractor and members of Standards Project Committee 160 in an advisory role, a research methodology was developed. The monitoring protocol involved three site visits to each home to perform such tasks as collecting basic house and equipment characteristics, installing loggers, performing testing to quantify envelope leakage and duct leakage and collection of data recorded by the loggers.

The project deliverable is a data base of test house characteristics with an overview summary of the test sample characteristics. Data compiled in the field tests has been analyzed to identify the potential relationships between certain household characteristics and the measured internal humidity levels. Potential relationships were also studied more closely for those homes noted as having moisture problems as compared to those that did not.

In this paper, the authors discuss the research design for this project including problems encountered and lessons learned. Specific topics will include candidate requirements, critical parameters measured/recorded and data manipulation and analysis. Samples of the data collected with some discussion of preliminary findings will also be presented