Page 332 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

294 Cha pte r S i x

ASHRAE was awarded a grant in 2006 from the EPA to develop a special publication
entitled Advanced Indoor Air Quality (IAQ) Design Guide for Non-Residential Buildings.
The document was expected to be complete in late 2008, and the work was being done
in conjunction with many other organizations including the USGCB, AIA, and
SMACNA. This document should be useful in comparing air quality alternatives and
designing innovative control methods.
Also, ASTM International is developing a standard that addresses methods for the
evaluation of residential indoor air quality. It is Standard D7297 and is under the
jurisdiction of Subcommittee D22.05 on Indoor Air, which is part of ASTM Committee
D22, Air Quality. The Center for Disease Control and Prevention, headquartered in
Atlanta, provides many other references for healthy indoor and outdoor environments.
A website with resources entitled “Designing and Building Healthy Places” can be
found at http://www.cdc.gov/healthyplaces/.
Air Pollution Calculation Conversions and Concentrations
Air pollutant concentrations and emission rates are typically reported in many units.
Conversion of these units is not always straightforward and is also dependent on the
temperature and pressure of the readings. Typically the values given from standard
testing are converted to standard temperature and pressure, which is at 1 atmosphere
(atm) (14.7 psia) and between 20 and 25°C. The following items can aid in understanding
these concepts and conversions to estimate air pollution levels.
Temperature
The SI temperature scale is in degrees Celsius (°C), and the absolute SI scale is in kelvins (K)
such that

K = °C + 273 (6.9.1)
The temperature scale in the United States, degrees Fahrenheit (°F), can be converted to
its absolute scale, degrees Rankine (°R), by the following:

°R = °F + 460 (6.9.2)
To convert between Celsius and Fahrenheit, the following equation is used:

°C = 1.8(°F − 32) (6.9.3)
Ideal Gas Law
The ideal gas law is a model that quantifies how the volumes and concentrations of
gases change with temperature and pressure. It can be used to model most gases and
mixtures of gases at typical ambient temperatures and pressures. The ideal gas law is
Eq. (6.9.4) and is based on the following variables:
P absolute pressure
V volume of gas
n moles of gas
R ideal gas law constant; one value is 0.0821 L · atm · (mol · K)
Ideal
T absolute temperature
PV = nR T (6.9.4)
Ideal