Civil Engineering Reference
In-Depth Information
Chapter 6
Indoor Air Quality
6.1
Main Sources of Problem
Having a high-quality indoor air is one of the most important factors in defi ning the
quality of any building. People's wellness and productivity have a direct relationship
with how well indoor air of the building that they live and work in has been designed
and maintained. Since people live and function inside the buildings and along with
the operating equipment and appliance in the building contribute to the age and lack
of freshness of the air inside the building, a continuous introduction of proper
amount of fresh air into the building is a vital factor in keeping a high-quality indoor
air condition.
Quantity of the fresh air inside the building has been the subject of many discus-
sions and has been continuously revised by the governing standards such as ASHRAE
standard (ASHRAE
2013
) through the years. In order to design and maintain a
building with a high-quality indoor air, designers should comply with the recom-
mendations specifi ed in these standards. This requires specifi c calculations, imple-
mentation provisions, monitoring, and verifying the contributing factors to air
quality. The current standard requires enough fresh air equal to result of a function
developed based on combination of number of people who are living and working
in each space and the total space area. The standard requires some correction in
order to increase the calculated required fresh air in order to compensate for every
area in receiving the minimum required calculated outdoor air. Since in mixing air
handling units, space return air will be mixed with outside air before discharging
into each space, basically even with these corrections there is no guarantee that
every single space receives the proper and calculated quantity of outdoor air.
Therefore some rooms may receive more than adequate, and some rooms may do
not receive enough outdoor air at all. As a result the best way to make sure all rooms
will receive proper quantity of outdoor air the best bet is to utilize dedicated outdoor
air units that deliver full outdoor air requirement of each space directly to that space.
