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

HVAC Control in the New MillenniumThe early southern houses were constructed with high ceilings,large porches which sheltered sections of the house from the direct raysof the sun and large window areas for ventilation. They were also usuallysituated on the site so that halls, major doors and sleeping areasfaced the direction of the prevailing winds. Today, with air conditioning,these considerations have not been given as much importance.Ventilation RequirementsVentilation is the process of supplying or removing air to or froma building or space. The air may or may not have been conditioned.Methods of supplying or removing the air include natural ventilationand mechanical methods.Natural ventilation involves opening or closing wall vents and byusing roof vents or ventilators. Mechanical ventilation is provided bythe use of fans or other means that force the air through the space to beventilated.Air Conditioning TrendsThere has been an increasing use of year-round air conditioningsystems that provide heating, ventilating, and cooling. These systemscondition the air by controlling its temperature (warming or cooling),cleanliness, moisture content and movement. Thus, the true meaning ofthe term air conditioning has been achieved.Air conditioning can be treated as the simultaneous control ofthose factors that affect the conditions of the atmosphere in a structure.These factors can include temperature, humidity, air motion and distribution,dust, bacteria, odors, and toxic gases which affect human healthand comfort.Air that has been properly conditioned generally has a combinationof processes performed on it. It may have been heated or cooled andmay have had moisture removed from it (dehumidified). Fans may beused to move the air and filters may be used for cleaning. The air actsas a vehicle to transport heat and moisture from one area. Air movementis one important technique of energy conservation.©2001 by The Fairmont Press, Inc. All rights reserved.