Civil Engineering Reference
In-Depth Information
As the sun radiation hits the earth and objects and people on it, some of this
radiation absorbs and increases the temperature of earth and objects on its surface.
This effect causes the earth and objects located on its surface generate infrared
thermal radiation and send it back up towards the atmosphere.
Ozone, water vapor, nitrous oxide, methane and many other gases, which exist in
the earth atmosphere and are known as greenhouse gases, have the capability of
absorbing the defl ected infrared thermal radiation of the earth and other object on its
surface. One of the major greenhouse gases is CO 2 that is after-production of
carbon-based fuels as source of energy generation. CFCs, HCFCs, HFCs, and vola-
tile organic compounds (VOCs) act as greenhouse gases as well. The specifi c attri-
bute of the greenhouse gases which is their capability to refl ect the absorbed thermal
radiation in all directions, causes some of the heat that was on its way to leave the
earth atmosphere refl ects back towards the earth. When this function repeatedly is
done, creates additional heat near ground that causes the earth temperature to rise.
This effect is known as global warming, which is known to be responsible for cli-
mate change and some extreme tsunamis or earth poles ice melting in the recent
years. Top human generated greenhouse gases that contribute to global warming are
CO 2 , CH 4 and N 2 O. Even though these greenhouse gases which also naturally occur
in the atmosphere but based on a report by Intergovernmental Panel on Climate
Change (IPCC) and National Oceanic & Atmospheric Administration (NOAA) the
atmospheric concentration of these greenhouse gasses in the past 250 years (indus-
trial era) have increased by 39 %, 158 %, and 18 %, respectively.
Ozone depletion and global warming are the most critical one-two punches that
the industrial age and as a major component of it, the building construction industry
has hit the people, the earth and its environment with. For more information on this
subject see ( http://www.epa.gov/ ).
As extreme usage of refrigerants in chillers and other machines and consequently
its leakage has endangered the atmosphere by depleting the ozone layer, and as
uncontrolled consumption of energy sources has endangered the easy access to
energy resources, different protocols and committees have diverted their attention to
higher effi ciency systems with lower damage to the environment and use of sustain-
able energy sources. Designers that their main goal was to design for the occupant's
comfort, faced other more critical criteria to comply with, such as sustainability and
design to the highest effi ciency levels with no damaging effect to the environment.
One of the most internationally infl uential organizations in this fi eld is American
Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE)
which was founded in 1894 at a meeting of engineers in New York City. ASHRAE
publishes a monthly journal, a set of four handbooks every year (once in 4 years
each), and performs multiple meetings throughout the year. Its four handbooks of
Refrigeration (ASHRAE 2014 ), Fundamentals (ASHRAE 2013b ), HVAC Systems
and Equipment (ASHRAE 2012 ), and HVAC Applications (ASHRAE 2011b ) that
are revised and republished every 4 years in order are one of the most valuable
resources for designers and researchers in HVAC fi eld. ASHRAE also has published
numerous standards regarding most aspects of design, control, and commissioning
of HVAC systems. The instructions of ASHRAE Standard 90.1 (ASHRAE 2013a ),
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