commercial buildings in the United States [77]. On
a global scale, taking climate change, global
warming, and rapid population growth into consideration, it is expected that the demand for energy
use for HVAC systems will increase [74, 76]. Some
studies have focused on the capacity of buildings to
produce and retain novel pollutants due to their
tightness and indoor sources. However, many
buildings are poorly insulated and equipped with
inefficient air conditioning systems, which lead to
increased energy consumption and maintenance
costs [76, 77]. There are some easy solutions to
increase the efficiency of the AC system. For
instance, the system should not operate at temperatures lower than 24
C, and it should be able to
adjust the flow of inlet air according to changes
throughout the day. In temperate climates, the use
of aiding systems such as free cooling coils can
reduce power consumption [75].
Many strategies can be used to design better
and more efficient HVAC and AC systems. The
U.S. National Institute of Building Sciences
(NIBS) posits that high-performance systems can
yield up to 40% monetary savings and reductions
in greenhouse gas emissions. In addition, designing buildings with an “extended comfort zone”
can achieve savings up to 70% [77]. Most buildings today could benefit from fundamental design
strategies to improve their overall efficiency. Most
strategies aim at improving the integration, connectivity, and responsivity of the building and the
conditioning systems. For instance, design teams
should consider climate control in the early stages
of the design process, in order to ensure the right
equipment size and distribution for the system,
consumption goals, scalability, and manage peak
use phases and the maintenance program [77].
The coefficient of performance (COP) is used
to measure the performance of air conditioning
systems [78].
COP ¼
Q
W
where:
Q = useful heat supplied or removed by the
system
W = work required by the system
Chillers are the usual go-to equipment for large
commercial buildings. They produce cold water
which in turn is used to cool the building. COP
values for these systems range from 2.2 to 3.2 for
small chillers. The COP generally improves as the
size of the system increases with values in the
range of 3.7–4.1 being typical for large
systems [77].
Remediation Methods
One way to decrease the level of pollution is to
minimize or eliminate the source. This can potentially take a very long time or may even be impossible. Another way is to apply methods that
remove pollutants directly from the air, such as
filter systems with implemented adsorbent materials, interior plants, or ventilation.
Gas Phase Advanced Oxidation
Providing good indoor air quality in a polluted
location can be a huge challenge. Increasing the
ventilation rate to bring in more air from the
outside would not necessarily improve indoor air
quality unless the air is thoroughly cleaned first.
Any solution would have to be able to clean large
volumes of air with low energy consumption. One
possible solution is the system being used at the
Danish Embassy in Beijing. The Embassy has
implemented a new air cleaning technology
invented by the University of Copenhagen and
produced by the company Infuser under a license.
As Beijing is one of the most polluted capitals in
the world [80], the Infuser air purifying system is
a good example of how to ensure IAQ when
natural ventilation is not an option. The method
is centered on the hydroxyl radical (OH) and is
inspired by air cleaning mechanism that takes
place in the free atmosphere. In the atmosphere,
pollutants are oxidized by OH-forming compounds with lower volatilities than their precursors. The oxidation products often form particles
that deposit or are washed out of the atmosphere.
OH formation is initiated by the photolysis of O 3 .
OH will then oxidize different VOCs entering the
system and the reaction products can condense
into particles that are removed by a particle filter.
The remaining ozone is removed over a catalyst.
Indoor Air Quality: Status and Standards
149
a global scale, taking climate change, global
warming, and rapid population growth into consideration, it is expected that the demand for energy
use for HVAC systems will increase [74, 76]. Some
studies have focused on the capacity of buildings to
produce and retain novel pollutants due to their
tightness and indoor sources. However, many
buildings are poorly insulated and equipped with
inefficient air conditioning systems, which lead to
increased energy consumption and maintenance
costs [76, 77]. There are some easy solutions to
increase the efficiency of the AC system. For
instance, the system should not operate at temperatures lower than 24
C, and it should be able to
adjust the flow of inlet air according to changes
throughout the day. In temperate climates, the use
of aiding systems such as free cooling coils can
reduce power consumption [75].
Many strategies can be used to design better
and more efficient HVAC and AC systems. The
U.S. National Institute of Building Sciences
(NIBS) posits that high-performance systems can
yield up to 40% monetary savings and reductions
in greenhouse gas emissions. In addition, designing buildings with an “extended comfort zone”
can achieve savings up to 70% [77]. Most buildings today could benefit from fundamental design
strategies to improve their overall efficiency. Most
strategies aim at improving the integration, connectivity, and responsivity of the building and the
conditioning systems. For instance, design teams
should consider climate control in the early stages
of the design process, in order to ensure the right
equipment size and distribution for the system,
consumption goals, scalability, and manage peak
use phases and the maintenance program [77].
The coefficient of performance (COP) is used
to measure the performance of air conditioning
systems [78].
COP ¼
Q
W
where:
Q = useful heat supplied or removed by the
system
W = work required by the system
Chillers are the usual go-to equipment for large
commercial buildings. They produce cold water
which in turn is used to cool the building. COP
values for these systems range from 2.2 to 3.2 for
small chillers. The COP generally improves as the
size of the system increases with values in the
range of 3.7–4.1 being typical for large
systems [77].
Remediation Methods
One way to decrease the level of pollution is to
minimize or eliminate the source. This can potentially take a very long time or may even be impossible. Another way is to apply methods that
remove pollutants directly from the air, such as
filter systems with implemented adsorbent materials, interior plants, or ventilation.
Gas Phase Advanced Oxidation
Providing good indoor air quality in a polluted
location can be a huge challenge. Increasing the
ventilation rate to bring in more air from the
outside would not necessarily improve indoor air
quality unless the air is thoroughly cleaned first.
Any solution would have to be able to clean large
volumes of air with low energy consumption. One
possible solution is the system being used at the
Danish Embassy in Beijing. The Embassy has
implemented a new air cleaning technology
invented by the University of Copenhagen and
produced by the company Infuser under a license.
As Beijing is one of the most polluted capitals in
the world [80], the Infuser air purifying system is
a good example of how to ensure IAQ when
natural ventilation is not an option. The method
is centered on the hydroxyl radical (OH) and is
inspired by air cleaning mechanism that takes
place in the free atmosphere. In the atmosphere,
pollutants are oxidized by OH-forming compounds with lower volatilities than their precursors. The oxidation products often form particles
that deposit or are washed out of the atmosphere.
OH formation is initiated by the photolysis of O 3 .
OH will then oxidize different VOCs entering the
system and the reaction products can condense
into particles that are removed by a particle filter.
The remaining ozone is removed over a catalyst.
Indoor Air Quality: Status and Standards
149