HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Heat, Ventilation and Damper Control Trends 1Chapter 1Heat, Ventilation andDamper Control TrendsThe first attempts at environmental control involved heat andventilation. The control of heat goes back to prehistoric timesand probably first developed in colder climates where warmertemperatures were needed for both comfort and health. Thetechnology of heating has advanced from simple attempts to keep thebody warm to the sophisticated systems of maintaining stabilized environmentsin order to minimize the heat loss from the body or the structuralsurfaces of the room.Ventilation also goes back to very early periods in history. The useof slaves to wave large fans and fan-like devices was an attempt toimprove the ventilation. Rooms or buildings were also arranged to takeadvantage of the rising and setting of the sun as well as prevailingbreezes and winds. By the end of the 18th century significant advanceswere being made in heating and ventilating.In the early stages of the Industrial Revolution, ventilating andheating acquired increased importance since it affected the work efficiencyand the health of the workers. This resulted in the creation ofventilation systems to remove contaminants from the air.Air ConditioningAir conditioning is a more recent development and encompassesall aspects of environmental control. In addition to the control of temperature,both humidity (the moisture content of the air) and air cleanlinessare regulated by air conditioning.The earliest attempts at air conditioning involved the placing ofwet cloths over air passages such as window openings and doors to cool©2001 by The Fairmont Press, Inc. All rights reserved.