TABLE OF CONTENTS Lawrence E. McCabe [*]
Chief Engineer-Mechanical
STV Group
Douglassville, Pennsylvania
The necessity of heating, ventilation, and air-conditioning (HVAC) control of environmental conditions within buildings has been well established over the years as being highly desirable for various types of occupancy and comfort conditions as well as for many industrial manufacturing processes. In fact, without HVAC systems, many manufactured products produced by industry that are literally taken for granted would not be available today.
Adiabatic Process. A thermodynamic process that takes place without any heat being added or subtracted and at constant total heat.
Air, Makeup. New, or fresh, air brought into a building to replace losses due to exfiltration and exhausts, such as those from ventilation and chemical hoods.
Air, Return (Recirculated). Air that leaves a conditioned spaced and is returned to the air conditioning equipment for treatment.
Air, Saturated. Air that is fully saturated with water vapor (100% humidity), with the air and water vapor at the same temperature.
Air, Standard. Air at 70 F (21 C) and standard atmospheric pressure [29.92 in (101.3 kPa) of mercury] and weighing about 0.075 lb/ft 3 (1.20 kg/m 3).
Air Change. The complete replacement of room air volume with new supply air.
Air Conditioning. The process of altering air supply to control simultaneously its humidity, temperature, cleanliness, and distribution to meet specific criteria for...
