A study to measure indoor concentrations and emission rates of volatile organic compounds (VOCs), including formaldehyde, was conducted in a new, unoccupied manufactured house installed at the National Institute of Standards and Technology (NIST) campus. The house was instrumented to continuously monitor indoor temperature and relative humidity, heating and air conditioning system operation, and outdoor weather. It also was equipped with an automated tracer gas injection and detection system to estimate air change rates every 2 h.
Effective weather resistive barriers (WRB) perform important functions in retarding waterentry into walls and in controlling water vapor movement as well as the amount of energyattributed to air leakage (Burnett, 2000; Weston et al 2001). Recognizing this, a public andprivate sector research consortium was established to develop reliable and precise methodsfor evaluating their performance.This paper, third in a series, provides an overview of the most significant results obtainedduring the consortium work.
The effect of residential central air conditioning on indoor spore counts was investigated. Six pairs of residential buildings were monitored for three days. The homes were both air conditioned and non-air-conditioned. An Andersen sampler was used and outdoor measurements were also taken. Kitchens and bedrooms of air conditioned homes revealed significantly lower spore counts. The study used multiple regression analysis to show that the lower spore counts were associated with lower relative humidity.
The rainscreen principle is not new. It was proposed as early as the mid sixties by researchers of the Division of Building Research of the National Research Council of Canada and the basic principles were developed. It has been applied to certain exterior wall types but the performance of rainscreen walls remains largely unknown because of the absence of engineering data.