Online Classes Heating, Ventilation, Air …

Page 1 HVACRedu.net Catalog 6/8/18 MASTER CATALOG Online Classes Heating, Ventilation, Air Conditioning, and Refrigeration New-to-the-Industry, Apprentice through Senior Technician Programs,

  Classes, Online, Ventilation, Conditioning, Refrigeration, Heating, Air conditioning, And refrigeration, Online classes heating

PNEUMATIC CONTROL FUNDAMENTALS

a valve or damper (Fig. 1). In a typical control system, the final control element (a valve or a damper) is selected first because it must produce the desired control results. For example, a system designed to control the flow of water through a coil requires a control valve. The type of valve, however, depends on whether the water is intended

  Valves

HVACR FORMULAS

HVACR FORMULAS . TON OF REFRIGERATION - The amount of heat required to melt a ton (2000 lbs.) of ice at 32°F . 288,000 BTU/24 hr. 12,000 BTU/hr. APPROXIMATELY 2 inches Hg. (mercury) = 1 psi. WORK = Force (energy exerted) X Distance . Example: A 150 lb. man climbs a flight of stairs 100 ft. high

Measuring Total Pressure and Velocity Pressure

In operating duct systems, a second pressure is always present. It s independent of air velocity or movement. Known as static pressure, it act equally in all directions. In air conditioning work, this pressure is also measured in inches w.c. In pressure or supply systems, static pressure will be positive on the discharge side of the fan.

  Pressure, Static, Duct, Static pressure