Comparative Performance of Two Ventilation Strategies in a Hot-Humid Climate

Abstract

The work presented in this report does not represent performance of any product relative to regulated minimum efficiency requirements. The laboratory and/or field sites used for this work are not certified rating test facilities. The conditions and methods under which products were characterized for this work differ from standard rating conditions, as described. Because the methods and conditions differ, the reported results are not comparable to rated product performance and should only be used to estimate performance under the measured conditions. 4 Conclusions .

Relationship among Concentrations of Indoor Air Contaminants, Their Sources, and Different Mitigation Strategies on Indoor Air Quality

“…The degree to which increased ventilation air reduces concentrations of some contaminants has also been shown to be dependent on the ventilation system type, particularly with respect to formaldehyde concentrations [2,[9][10][11]. Specifically, Hun et al [9] and Rudd and Bergey [10] have also demonstrated that supply-based systems may be more effective at reducing formaldehyde concentrations than exhaust-only systems.…”

“…The validation is based, primarily, on data from a previous study which evaluated the impact of two ventilation strategies on energy use, temperature, relative humidity, indoor air quality contaminant levels, and comfort [2]. The data were gathered in 10 homes in Gainesville, FL that were all newly occupied in the 2009-2010 time frame, are in the same subdivision, have similar specifications, and were built to Builders Challenge 1.0 guidelines.…”

“…One-week sampling periods were chosen to characterize longer-term exposures in homes, including any weekly or daily variations. While the passive sampling method does not allow for quantifying the time-dependent variation of these parameters, the average long-term impact of any increased or decreased concentrations are reflected in the weekly time-averaged sample and lends itself to the average analytical approach proposed by the general model discussed in Section 1.2 [2] contains more details regarding the passive samplers used and quality assurance methods applied to data collection.…”

“…We believe that such a model can be used to compare and develop recommendations about different approaches in different climates and housing types. The article also illustrates application of the model to data collected in 10 homes in Gainesville, FL [2].…”

“…Therefore, the source strength of any contaminant i can be reduced by decreasing the emission rate of the contaminant from these areal sources, or decreasing the surface area of the contaminant that is in contact with the indoor air or ventilation air. Research has shown that that some contaminants may have emission rates that depend on the concentration of that contaminant in the air, the ambient temperature and relative humidity, or other factors [1,2,8,13]. For other indoor contaminants, the source strength is not surface area dependent, but may depend on some other mechanism (e.g., the rate of vaporization or combustion for showering or cooking, respectively).…”