Environmental Engineering Reference
In-Depth Information
to comply and facilitates the determination by enforcing bodies of whether
compliance has been achieved.
Under its “continuous maintenance” process, ASHRAE has adopted and
proposed a number of addenda. In the former category, addenda to Standard
62-1989: (1) clarify the intent of the standard to “minimize the potential for
adverse health effects,” (2) change the standard's designation to indicate its
status as an ANSI Standard, (3) indicate that the standard may not achieve
acceptable IAQ because of the presence of some contaminants and varied
susceptibilities of occupants, (4) eliminate language that the standard could
accommodate a moderate amount of smoking, and (5) clarify language on
CO
. Proposed addenda, which at the time of this writing are under public
review, include (1) requirements for classification, signage, and separation
of areas where smoking is permitted; (2) an updated version of the IAQ
Procedure, a performance-based approach in which a building and its ven-
tilation system are designed to maintain contaminants below acceptable
levels and indicate where the IAQ Procedure can be used (also see Chapter
11); (3) revisions on how natural ventilation can be used; (4) description of
how the standard applies to new and existing buildings; (5) recommenda-
tions and requirements on construction and ventilation system startup, oper-
ation, and maintenance; (6) revisions in the procedure for determining design
ventilation rates; (7) recommendations for providing ventilation for smoking
rooms and other rooms where smoking is permitted; and (8) recommenda-
tions on how to provide combustion air to dilute water vapor, CO
2
, and other
contaminants produced by indoor combustion appliances and how to pro-
vide sufficient ventilation air.
In its operation and maintenance addendum, ASHRAE is proposing the
use of Standards of Performance (SOPs) for HVAC systems, and maintenance
requirements pertinent to acceptable IAQ in buildings. Standards of perfor-
mance are defined by ASHRAE as standards that ensure a building system
or component is operating properly — determined through a series of mea-
sures. The measure may be a property, process, dimension, material, rela-
tionship, concept, nomenclature, or test method. ASHRAE has developed a
consensus SOP structure to ensure consistency for three levels of evaluation:
building, system, and component. Standards of performance documents
include seven sections, the first of which describes basic information on the
building, system, or component; the others describe how to evaluate system
performance and provide information on corrective action. An example of
an IAQ SOP for a central AHU is indicated in
Figure 13.3
.
Such SOPs can
be evaluated by comparing them to measurements and calculations.
More extensive maintenance requirements are being developed to
reflect research results and recognition that HVAC system maintenance can
affect IAQ (see the relationship between maintenance level and perception
of IAQ degradation in
Figure 13.4
)
. The ASHRAE 62 Projects Committee
has determined that maintenance requirements for the code version of the
document should address fundamental maintenance activities applicable to
a wide range of HVAC systems. These would include filters/air cleaning
2
