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"HVAC &
Educational Facilities Part 2 of 3"
The Comfort Zone
May/June 2001
by Maury Tiernan |
The Comfort Zone column, written for this mobile/modular industry magazine,
deals with the challenges related to HVAC systems in all commercial factory
built structures. This is the second of three articles focused on issues that
arise involving HVAC systems in educational facilities. This discussion will
pertain to site built as well as commercial factory-built schools.
Part 1 focused on the importance of "ventilation" and its value as the cheapest
"first-remedy" for IAQ Complaints. While maintaining a proper 15 CFM per
person, intake and exhaust ventilation during occupied times is not the only
answer to IAQ problems. It is easily manageable and within your control.
Part 2 of 3 will address the "human element" and the cause/effect relationship
between people and the HVAC systems in our educational facilities. Probably the
first person coming to mind in this equation is the teacher. While teachers do
play an important role in HVAC/indoor climate control, they are not involved at
the beginning of this story. Creating that "comfortable" and safe indoor
learning environment for students and teachers starts way before the students
arrive for class.
In the beginning, school district facility personnel and/or a mechanical
engineer develop the initial specifications for the HVAC systems. By involving
the mechanical engineer, the district can mitigate problems before they arise.
Although school districts may want to save the consulting cost up front,
without the mechanical engineer's expertise, they usually end up with
incomplete HVAC specifications, which result in more costly remedial action
after occupancy. A mechanical engineer will know how and when to include
appropriate mechanical, energy, and installation codes/requirements in the
initial bid specifications.
Proper bid specifications are invaluable. Due to the nature of the competitive
construction industry, if specific or performance specifications are not
included, then the contractors bidding your project may not include them.
Without them, your system may cost less, but be incomplete and unable to
function well.
Bid specifications should cover very basic issues such as:
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Correct duct sizing
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Equipment selection
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Control selection
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Register/grill performance
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Maximum noise levels
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Minimum energy requirements
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Ventilation requirement
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Air balance to specs
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Commissioning system
The next "human elements" involve the contributions of the estimator and the
construction group. The estimator interprets the specification to develop the
bid. If the bid specs have grey areas, expect the same of your end result.
HVAC systems are typically installed based on the successful lowest bid. During
construction, the mechanical engineer, code inspectors, quality assurance
personnel and installers are all responsible for proper installation. Is the
job being installed according to the bid specs, plans and the required codes?
Did the specifications communicate everything clearly and completely? District
facility personnel can expect to continue to receive what they have been
getting, if no changes are made.
After installation, the HVAC systems should be air balanced and receive a
proper system commissioning. Minimum circulated and ventilation air
requirements must be met for noiseless and draft-less operation as specified.
So now, after installation construction and proper system commissioning are
complete, the teacher and students occupy the classroom and the critique the
"comfortable" part of the system requirement. If hot/cold spots, noisy or
drafty areas persist, teachers may first call the maintenance department, or
they take matters into their own hands. Teachers have learned to adapt. They
know fifty ways to get into thermostat guards, turn the units off because of
noise, or use blow dryers/hot pads to affect the temperature.
School district maintenance personnel, those people who should be looking out
for the district's interest, may not be. Do they change-out and re-install the
correct filters regularly? Do they close fresh air intakes to slow filter
changing, but in so doing, worsen indoor air quality? Do they spray pesticides
at improper times? Finally, do district facility personnel have and use a
proactive IAQ program like the EPA's "Tools for Schools" program?
School districts will benefit from proper effort in the initial specification
phase, secondary construction phase, and final maintenance and operation phase.
Until the next time we meet, involve yourself in . . . The Comfort Zone.
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