Paper 5: Volume 5 No.2 Sept 2006 Edition
Comparative
Energy Analysis of a Constant Air Volume (CAV) System and a Variable Air
Volume (VAV) System for a Software Laboratory
Kalaiselvam.
S1, Vidhya sagar Velichet.1, Iniyan. S1
and Anand A. Samuel2
1Refrigeration
and Air Conditioning Division, Department of Mechanical Engineering,
Anna
University
,
Chennai
,
India
.
2President, ISHRAE Chennai chapter,
Vellore Institute of
Technology, Deemed University,
Vellore
,
India
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Abstract
The objective of heating,
ventilating and air conditioning (HVAC) systems is to satisfy users when
it comes to health, indoor air quality (IAQ), and thermal comfort. Air
conditioning systems employed to provide thermal comfort and indoor air
quality consume a significant part of building energy requirements. Any
effort to minimise energy consumption improves cost effectiveness and
economics. A variable air volume (VAV) system is a choice in that
direction. In this research, a relative energy consumption analysis of a
constant air volume (CAV) system and VAV system has been performed. For
the purpose of this study, a software laboratory was taken and the load
pattern was determined. For the derived load pattern an energy analysis of
major components of the HVAC system was carried out. It was found that
energy savings in the chiller varied from 14 % to 20 % and that
fan energy savings were between 20 % and 48 %. To meet indoor
air quality (IAQ) requirements a ventilation strategy based on air quality
demand control ventilation (DCV) was evaluated. This took into account the
contaminants generated from both human and other sources such as the
building and equipment, etc.
Key words: variable air
volume (VAV), demand control ventilation (DCV), energy savings, indoor air
quality, thermal comfort, HVAC component energy analysis, variable
occupancy.
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