12
Chapter One
is an international mandate as well as a moral and economic imper-
ative to design systems which are modest in their use of energy. Al-
though the United States lacks a well-defined national energy policy,
local and regional energy codes give some direction to the HVAC sys-
tems designer. These codes encourage the construction of buildings
which have lower inherent energy requirements, lighting systems
which derive more illumination from fewer watts, and air-handling
systems which move more air and water with less fan, pump, and
compressor power. Most of these codes are based on the American
Society of Heating, Refrigerating, and Air-Conditioning Engineers
(ASHRAE) Standard 90.1.
In a time when much HVAC design involves the renovation and
retrofit of older buildings and systems, there is good opportunity for
substitution of components and system concepts which will provide
similar or improved comfort by using less energy. Thus we suggest the
five T’s of energy conservation in both new and retrofit construction:
1.
Turn it off !
There is no substitute for the off switch. Provide a
mechanism to turn off energy-using systems when they are not
needed.
2.
Turn it down!
If it has to run, design it to run at the lowest level
which will still meet the duty. Try to provide modulating control
for all energy consumers.
3.
Tune it up!
To operators: Keep things in good operating condition.
To designers: Design for reliability and for maintainability.
4.
Turn it around!
For retrofit designers: If you find a system which
consumes disproportionate amounts of energy, improve it.
5.
Throw it away!
If a system is an energy hog and does not lend
itself to rehabilitation, be willing to take it out. The retrofit design
market for the year 2000 on into the next decades is a major in-
dustry market.
One good thing about energy conservation is that it nearly always
pays for itself. But sometimes a bit of teaching and long-term vision
are needed to get the message to the person controlling the purse
strings.
A word of caution. Energy conservation is important in HVAC de-
sign, but it is not the purpose or function of the HVAC system. HVAC
systems are intended to provide comfort, or a controlled environment.
If we conserve energy to the point that we lose sight of the system’s
function, then we have failed in our duty. There is no glory in owning
a building that drives tenants away with its energy-conserving but
uncomfortable HVAC systems. Nor is there gratitude to an energy
manager in an electronics plant where the production yield drops for
HVAC Engineering Fundamentals: Part 1
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