Temperature – °F to °C
Temperature is expressed as Fahrenheit (°F) in IP unit and Celsius (°C) in SI unit.
To convert temperature from IP to SI, minus the IP value by 32 and multiply it by 5/9. For example, (1°F – 32) * 5/9 = -17.22°C.
Meanwhile, 1°C = 273.15 Kelvin.
Water Flow Rate – gpm to L/s & m³/hr
Water flow rate is expressed as gallon per minute (gpm) in IP unit and litre per second (L/s) in SI unit. Another commonly used SI unit for volume is cubic meter per hour (m³/hr).
The IP to SI conversion factor from gpm to L/s as per ASHRAE is 0.00631.
So, to convert water flow rate from IP to SI, multiply the IP value by 0.0631. For example, 1 gpm x 0.0631 = 0.0631 L/s.
Meanwhile, 1 L/s = 3.6 m³/hr.
Volume – cfm (ft³/min) to L/s & cmh (m³/hr)
Volume is expressed as cubic feet per minute, cfm (ft³/min) in IP unit and litre per second (L/s) in SI unit. Another commonly used SI unit for volume is cubic meter per hour, cmh (m³/hr).
The IP to SI conversion factor from cfm (ft³/min) to L/s as per ASHRAE is 0.471947.
So, to convert volume from IP to SI, multiply the IP value by 0.471947. For example, 1 cfm x 0.471947 = 0.471947 L/s.
In addition, the IP to SI conversion factor for ft³ to m³ as per ASHRAE is 0.02832 and the conversion from minute to hour is 60. Hence, the consolidated conversion multiplier is 0.02832 x 60 = 1.6992.
So, to convert volume from cfm (ft³/min) to cmh (m³/hr), multiply cfm (ft³/min) by 1.6992. For example, 1 cfm x 1.6992 = 1.6992 cmh.
Velocity – fpm (ft/min) to m/s
Velocity is expressed as feet per minute, fpm (ft/min) in IP unit and meter per second (m/s) in SI unit.
The IP to SI conversion factor as per ASHRAE is 0.00508.
So, to convert velocity from IP to SI, multiply the IP value by 0.00508. For example, 1 fpm x 0.00508 = 0.00508 m/s.
Pressure – psi to kPa
Pressure is expressed as pound per square inch (psi) in IP unit and kilo Pascal (kPa) in SI unit.
The IP to SI conversion factor as per ASHRAE is 6.895.
So, to convert friction loss from IP to SI, multiply the IP value by 6.895. For example, 1 psi x 6.895 = 6.895 kPa.
Meanwhile, 100 kPa = 1 Bar.
Friction Loss – in.wg/100ft to Pa/m
Friction loss is expressed as inch of water gauge per 100 feet (in.wg/100ft) in IP unit and Pascal per meter (Pa/m) in SI unit.
The IP to SI conversion factor from inch of water (60°F) to Pascal as per ASHRAE is 248.84. In addition, the conversion factor from feet to meter as per ASHRAE is 30.48.
So, to convert friction loss from IP to SI, multiply the IP value by 248.84 and divide it by 30.48. For example, 1 in.wg/100ft x 248.84 ÷ 30.48 = 8.16404 Pa/m.
Thermal Conductivity (k Value) – Btu.in/hr.ft².°F to W/m.K
Thermal conductivity (k value) is expressed as British thermal unit inch per hour feet-square Fahrenheit (Btu.in/hr.ft².°F) in IP unit and Watt per meter Kelvin (W/m.K) in SI unit.
The IP to SI conversion factor as per ASHRAE is 0.1442279.
So, to convert thermal conductivity from IP to SI, multiply the IP value by 0.1442279. For example, 1 btu.in/hr.ft².°F x 0.1442279 = 0.0144279 W/m.K.
Overall Heat Transfer Coefficient (U Value) – Btu/hr.ft².°F to W/m².K
Overall heat transfer coefficient (U value) is expressed as British thermal unit per hour feet-square Fahrenheit (Btu/hr.ft².°F) in IP unit and Watt per meter-square Kelvin (W/m².K) in SI unit.
The IP to SI conversion factor as per ASHRAE is 5.678263.
So, to convert thermal conductivity from IP to SI, multiply the IP value by 5.678263. For example, 1 Btu/hr.ft².°F x 5.678263 = 5.678263 W/m².K.
Thermal Resistance (R Value) – ft².hr.°F/Btu to m².K/W
Thermal resistance (R value) is expressed as feet-square hour Fahrenheit per British thermal unit (ft².hr.°F/Btu) in IP unit and meter-square Kelvin per Watt (m².K/W) in SI unit.
The IP to SI conversion factor as per ASHRAE is 0.17611.
So, to convert thermal resistance from IP to SI, multiply the IP value by 0.17611. For example, 1 ft².hr.°F/Btu x 0.17611 = 0.17611 m².K/W.