A complete list of common refrigeration calculation formulas!

1. Conversion of temperature

Start with the simplest first-temperature conversion

Celsius (C) and Fahrenheit (F)

Fahrenheit = 32 + Celsius × 1.8

Celsius = (Fahrenheit -32)/1.8

Kelvin (K) and Celsius (C)

Kelvin temperature (K) = degrees Celsius (C) +273.15

02, pressure conversion

Mpa, Kpa, pa, bar

1Mpa=1000Kpa;

1Kpa=1000pa;

1Mpa=10bar;

1bar=0.1Mpa=100Kpa;

1 atmospheric pressure=101.325Kpa=1bar=1kg;

bar, Kpa, PSI

1bar=14.5psi;

1psi=6.895Kpa;

mH2O

1 kg/cm2=105=10 mH2O=1 bar=0.1 MPa

1 Pa=0.1 mmH2O=0.0001 mH2O

1 mH2O=104 Pa=10 kPa

03. Conversion of wind speed and volume

1 CFM (cubic feet per minute)=1.699 M³/H=0.4719 l/s

1 M³/H=0.5886CFM (cubic feet/minute)

1 l/s=2.119CFM (cubic feet per minute)

1 fpm (feet per minute)=0.3048 m/min=0.00508 m/s

04. Cooling capacity and power

1 KW=1000 W

1 KW=861Kcal/h (kcal)=0.39 P (cooling capacity)

1 W= 1 J/s (Joke/sec)

1 USTR (U.S. cold ton)=3024Kcal/h=3517W (cooling capacity)

1 BTU (British thermal unit)=0.252kcal/h=1055J

1 BTU/H (British thermal unit/hour)=0.252kcal/h

1 BTU/H (British thermal unit/hour)=0.2931W (cooling capacity)

1 MTU/H (thousand British thermal units/hour)=0.2931KW (cooling capacity)

1 HP (electricity)=0.75KW (electricity)

1 KW (electricity) = 1.34HP (electricity)

1 RT (cold capacity)=3.517KW (cold capacity)

1 KW (cooling capacity)=3.412MBH (103 British thermal units/hour)

1 P (cooling capacity)=2200kcal/h=2.56KW

1 kcal/h=1.163W

05, simple calculation formula

1. Selection of expansion valve: cold ton + 1.25% margin

2. Press power: 1P=0.735KW

3. Refrigerant charge: cooling capacity (KW) ÷ 3.516×0.58

4. Water flow of air-cooled machine: cooling capacity (KW) ÷ temperature difference ÷ 1.163

5. Cold water flow of water-cooled screw machine: cooling capacity (KW)×0.86÷temperature difference

6. Cooling water flow of water-cooled screw machine: (cooling capacity KW + compressor power) × 0.86 ÷ temperature difference

06. Line thickness and cooling capacity

★1.5mm2 is 12A-20A (2650~4500W)

★2.5mm2 is 20-25A (4500~5500W)

★ 4 mm2 is 25-32A (5500~7500W)

★ 6 mm2 is 32-40A (7500~8500W)