System Design Guidelines (cont.)

Sound Power and Sound Power Level. . . . . . . . . . . . . . . . . 32Sound Pressure and Sound Pressure Level . . . . . . . . . . . . 33Room Sones —dBA Correlation . . . . . . . . . . . . . . . . . . . . . 33Noise Criteria Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Design Criteria for Room Loudness. . . . . . . . . . . . . . . . .35-36Vibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Vibration Severity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38-39

General Ventilation Design

Air Quality Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Air Change Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Suggested Air Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Ventilation Rates for Acceptable Indoor Air Quality . . . . . . . 42Heat Gain From Occupants of Conditioned Spaces . . . . . . 43Heat Gain From Typical Electric Motors. . . . . . . . . . . . . . . . 44Rate of Heat Gain Commercial Cooking Appliances in Air-Conditioned Areas. . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Rate of Heat Gain From Miscellaneous Appliances . . . . . . 46Filter Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Relative Size Chart of Common Air Contaminants . . . . . . . 47Optimum Relative Humidity Ranges for Health . . . . . . . . . . 48

Duct Design

Backdraft or Relief Dampers . . . . . . . . . . . . . . . . . . . . . . . . 49Screen Pressure Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Duct Resistance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Rectangular Equivalent of Round Ducts . . . . . . . . . . . . . . . 52Typical Design Velocities for HVAC Components. . . . . . . . . 53Velocity and Velocity Pressure Relationships . . . . . . . . . . . 54U.S. Sheet Metal Gauges . . . . . . . . . . . . . . . . . . . . . . . . . . 55Recommended Metal Gauges for Ducts . . . . . . . . . . . . . . . 56Wind Driven Rain Louvers. . . . . . . . . . . . . . . . . . . . . . . . . . 56

Heating & Refrigeration

Moisture and Air Relationships . . . . . . . . . . . . . . . . . . . . . . 57Properties of Saturated Steam . . . . . . . . . . . . . . . . . . . . . . 58Cooling Load Check Figures . . . . . . . . . . . . . . . . . . . . . .59-60Heat Loss Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . .61-62Fuel Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Fuel Gas Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Table of Contents