Nate Formulas Exam With Complete Solution Graded A+

Fan law: Pulley size Formula - Answer-DPm X RPMm = DPf X RPMf DP=Diameter of Pulley f=Fan or Driven m=Motor or Driver Actual Brake HP of a motor - Answer-BHP = HPnp( Amps/FLA) np = Name plate Synchronizes speed of a motor - Answer-7200 / # of poles Convert Velocity pressure (Vp) into Feet Per Minute (FPM) - Answer-FPM = 4005(sqrt of Vp) Convert V(velocity) into CFM - Answer-CFM = Asqft X Vfpm Asqft = Area of the ductwork in square feet Vfpm = Velocity in Feet Per Minute Tp(total pressure) equals - Answer-Tp = Static (Sp) + Velocity (Vp) The formula to figure the BTUH of an ac system using field measurements - Answer-BTUH = 4.5(CFM) x (Delta Enthalpy) Fan law: Basic fan law formula - Answer-BHP2 = BHP1 X ((RPM2 / RPM1)cubed) Shows that required power of a motor varies by the Cube of the speed increase of that motor. The formula to figure the CFM of a Gas furnace using field measurements. - Answer-CFM = BTUH(output) / 1.08 X Delta T1.08 = 60(.075 X 0.24) 60 = Adjust formula to one hour Density of Dry air (.075) Specific heat (0.24) of Dry Air The formula to figure the CFM of an electric furnace - Answer-CFM = (E X I) X 3.414 / 1.08 X Delta T E X I = watts of the heating elements 3.414 converts watts to BTU's Fan law: The formula to determine BTUH of a Gas furnace using field measurements. - Answer-BTUH = 1.08 X CFM X Delta T Chiller load formula - Answer-BTUH = GPM X 60 X 8.33 X Delta T or BTUH = GPM X 500 X Delta T Convert Centigrade to Fahrenheit - Answer-C = (F - 32) / 1.8 Convert Fahrenheit to Centigrade - Answer-F = (1.8 X C) + 32 U value of insulation is equal to? - Answer-1/R Where R is the R value of the insulation. R value of insulation is equal to? - Answer-1/U Where U is the U value of the insulation. Area of a circle - Answer-A = pi X Rsq Formula for Power in Watts - Answer-W = I X E