Indoor Air Quality Impacts of Residential HVAC Systems. Phase II.A Report: Baseline and Preliminary Simulations.
Indoor Air Quality Impacts of Residential HVAC Systems.
Phase II.A Report: Baseline and Preliminary
Simulations.
(4910 K)
Emmerich, S. J.; Persily, A. K.
NISTIR 5559; 77 p. January 1995.
Sponsor:
Consumer Product Safety Commission, Washington, DC
Available from:
National Technical Information Service
Order number: PB95-178893
Keywords:
air flow modeling; building technology; heating;
ventilation; air conditioning; computer simulation;
filtration; heat recovery ventilator; indoor air
quality; infiltration; residential buildings;
ventilation; quality control
Abstract:
NIST has completed Phase II.A of a project to study the
impact of HVAC systems on residential indoor air quality
and to assess the potential for using residential
forced-air systems to control indoor pollutant levels.
In this effort, NIST is performing whole building
airflow and contaminant dispersal computer simulations
with the program CONTAM93 to assess the ability of
modifications of central forced-air heating and cooling
systems to control pollutant sources relevant to the
residential environment. This report summarizes the
results of Phase II.A of this project, which consisted
of three major efforts: baseline simulations of
contaminant levels without indoor air quality (IAQ)
controls, design of the IAQ control retrofits, and
preliminary simulations of contaminant levels with the
IAQ control retrofits. In Phase II.B of the study, all
of the baseline cases will be modified to incorporate
the IAQ control retrofits. The retrofit results will
then be compared to the baseline results to evaluate the
effectiveness of the retrofits. The pollutant
concentrations in a building depend on many factors
including the configuration of the building zones, the
air leakage of the building envelope and of interior
partitions, wind pressure profile on the building
envelope, pollutant source strengths and temporal
profiles, heating and cooling system airflow rates,
furnace filter efficiency, characteristics of reversible
pollutant sinks in the building, individual pollutant
decay or deposition rates, and ambient weather and
pollutant concentrations. This report describes the
input data used to model the baseline houses with
CONTAM93 and presents the resultsof the baseline
simulations in the form of the transient pollutant
concentrations for selected simulations and a summary of
peak and average concentrations for all baseline
simulations. Three indoor air quality control
technologies were then selected for incorporation into
the baseline house models to determine their
effectiveness in controlling the modeled pollutant
sources. The technologies include the following:
electrostatic particulate filtration, heat recovery
ventilation, and an outdoor air intake damper on the
forced-air system return. Selected baseline cases were
then modified to implement these indoor air quality
control retrofits, and preliminary simulations were
performed to demonstrate the ability of the program to
model the control techniques.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899