HVAC Calculation Formula

I, Mocheso:

Celsius (C) le Fahrenheit (F)

Fahrenheit = 32 + Celsius × 1.8

Celsius = (Fahrenheit -32) /1.8

Kelvin (K) le Celsius (C)

Kelvin (K) = Celsius (C) +273.15

II, Phetoho ea Khatello:

Mpa, Kpa, pa, bar

1Mpa=1000Kpa;

1Kpa=1000pa;

1Mpa=10bar

1bar=0.1Mpa=100Kpa;

1atmospher=101.325Kpa=1bar=1Kilogram;

1bar=14.5psi;

1psi=6.895Kpa;

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

III, lebelo la moea, phetoho ea molumo

1CFM =1.699 M³/H=0.4719 l/s

1M³/H=0.5886CFM

1l/s=2.119CFM

1FPM=0.3048 m/min=0.00508 m/s

IV, Bokhoni ba ho pholisa le matla:

1KW=1000 W

1KW=861Kcal/h=0.39 P (bokhoni ba ho pholisa)

1W=1 J/s

1USTR=3024Kcal/h=3517W (bokhoni ba ho pholisa)

1BTU=0.252kcal/h=1055J

1BTU/H=0.252kcal/h

1BTU/H=0.2931W (bokhoni ba ho pholisa)

1MTU/H=0.2931KW (bokhoni ba ho pholisa)

1HP (motlakase)=0.75KW (motlakase)

1KW (motlakase) = 1.34HP (motlakase)

1RT(bokhoni ba ho pholisa)=3.517KW (bokhoni ba ho tsidifatsa)

1KW (bokhoni ba ho pholisa）=3.412MBH

1P (bokhoni ba ho pholisa）=2200kcal/h=2.56KW

1kcal/h=1.163W

V,Sefehla moeabotenya ba ho kenya le bokhoni ba ho futhumatsa:

1.5mm2=12A-20A (2650~4500W) 1P~2P

2.5mm2=20-25A (4500~5500W) 2P

4mm2=25-32A (5500~7500W) 2P~3P

6mm2=32-40A (7500~8500W) 3P~4P

VI, foromo ea lipalo ea sehatsetsing:

1, Khetho ea valve ea ho atolosa: tone e batang + 1.25% tumello

2, Matla a ho hatisa: 1P= 0.735kW

3, Tefiso ea sehatsetsing: Bokhoni ba ho pholisa (KW) ÷3.516 x 0.58

4、 Phallo ea metsi ea moea o pholileng: Bokhoni ba ho futhumatsa (KW) ÷ phapang ea mocheso ÷1.163

5, Sekhahla sa phallo ea metsi a pholileng ea mochini oa screw o pholileng ka metsi: Bokhoni ba ho futhumatsa (KW) × 0.86÷ phapang ea mocheso

6 、 Sekhahla sa phallo ea metsi a pholileng ea mochini oa screw o pholileng ka metsicooling capacityKW+ tobetsa matla) × 0.86÷ phapang ea mocheso

7, Boleng bo felletseng ba ho futhumatsa QT=QS+QL

8, Pholiso ea moea: QT =0.24*∝*L*(h1-h2)

9, Pholiso ea bohlokoa ea moea oa mocheso: QS=Cp*∝*L*(T1-T2)

10, mocheso o patehileng oa moea o pholileng: QL = 600 * ∝ * L * (W1-W2)

11,Metsi a leqhoabophahamo ba modumo:L/sV1= Q1/(4.187△T1)

12, bophahamo ba metsi a pholileng: L/sV2=Q2/(4.187△T2)=(3.516+KW/TR)TR，Q2=Q1+N=TR*3.516+KW/TR*TR=(3.516+KW/TR) *TR

13, Katleho ea sehatsetsing: EER= Bokhoni ba sehatsetsi (Mbtu / h) / tšebeliso ea matla (KW);COP= Bokhoni ba sehatsetsi (KW)/tšebeliso ea matla (KW)

14, ts'ebetso ea mojaro o pholileng o sa fellang: NPLV=1/(0.01/A+0.42/B+0.45/C+0.12/D)

15、Moroalo o felletseng oa hajoale (mohato o meraro):FLA=N/√3 UCOSφ

16, bophahamo ba moea o mocha: Lo=nV

17, Moeaphepelo bophahamo ba modumo: L=Qs/〔Cp*∝*(T1-T2)〕

18, Matla a fan:N1=L1*H1/(102*n1*n2)

19, Matla a pompo ea metsi: N2 = L2*H2*r/(102*n3*n4)

20, bophara ba phala: D=√4*1000L2/(π*v)

21, Sebaka sa kotopo: F=a*b*L1/(1000u)