ABSTRACT
The intent of going green is to create a more energy-efficient, environmentally friendly indoor air environment. In the past, energy efficiency was synonymous with a tight building. Tighter is better! However, closing in and sealing up buildings in occupied, conditioned air spaces led to trapped emissions from building materials, furnishings, and other products. Tight buildings resulted in “sick building syndrome.”
In the 21st century, “green” is being redefined. The champions of green now seek to certify green buildings as those that have minimal impact on the environment and are healthy for building occupants. The playing field has changed. Health and indoor air quality must work together with energy efficiency. This is where the environmental professional has a defined proactive role to play.
The principle parties involved in the “green movement” are the Leadership in Energy and Environmental Design (LEED) approach and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard. Both the LEED and the ASHRAE standards are voluntary, best-practice directives for healthy indoor air quality. They both have a provision for building flush-out 1 and/or for preoccupancy air monitoring. The flush-out and preoccupancy air monitoring methods are similar, yet different. The LEED approach is not required, whereas the ASHRAE Standard flush-out is required. And the LEED program has altered its maximum concentration limits, which is now referred to as the LEEDV4 method.
Flush-out is a reference to the replacement of all indoor serviced air by outdoor air. The flush-out rate is the volume of outdoor air required to replace the same volume of indoor air for each area serviced.
