HVAC Xam Xaj Formula

I, Kub:

Celsius (C) thiab Fahrenheit (F)

Fahrenheit = 32 + Celsius × 1.8

Celsius = (Fahrenheit -32) /1.8

Kelvin (K) thiab Celsius (C)

Kelvin (K) = Celsius (C) + 273.15

II, Pressure conversion:

Mpa, Kpa, pa, bar

1Mpa = 1000Kpa;

1 Kpa = 1000 hli

1 Mpa = 10bar;

1bar = 0.1Mpa = 100Kpa;

1 atmosphere = 101.325Kpa = 1bar = 1 Kilogram;

1bar = 14.5 psi;

1 psi = 6,895 Kpa;

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, Cua ceev, ntim hloov dua siab tshiab

1CFM = 1.699 M³/H = 0.4719 l/s

1M³/H = 0.5886CFM

1 l/s = 2.119CFM

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

IV, Lub peev xwm txias thiab lub zog:

1 KW = 1000 W

1KW = 861 Kcal / h = 0.39 P (txias muaj peev xwm)

1 W = 1 J/s

1USTR = 3024 Kcal / h = 3517W (txias muaj peev xwm)

1 BTU = 0.252 kcal/h = 1055J

1 BTU/H = 0.252 kcal/h

1BTU / H = 0.2931W (txias muaj peev xwm)

1MTU/H = 0.2931KW (txias muaj peev xwm)

1HP (hluav taws xob) = 0.75KW (hluav taws xob)

1KW (hluav taws xob) = 1.34HP (hluav taws xob)

1RT (txias muaj peev xwm) = 3.517KW (txias muaj peev xwm)

1KW (txias muaj peev xwm)= 3.412 MBH

1P (txias muaj peev xwm)= 2200 kcal/h = 2.56 KW

1 kcal/h = 1.163 W

V,Cua txiasinstallation thickness thiab txias muaj peev xwm:

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, Refrigerant suav mis:

1, Kev xaiv ntawm expansion valve: txias tuj + 1.25% nyiaj pub dawb

2, Xovxwm fais fab: 1P = 0.735kW

3, Tus nqi tub yees: Lub peev xwm txias (KW) ÷ 3.516 x 0.58

4, Dej ntws ntawm cua txias: Lub peev xwm txias (KW) ÷ kub qhov sib txawv ÷ 1.163

5 、 Cov dej txias ntws ntawm cov dej txias ntsia hlau tshuab: Lub peev xwm txias (KW) × 0.86÷ qhov kub thiab txias

6 、 Txias dej ntws tus nqi ntawm cov dej txias ntsia hlau tshuabtxias peevKW + xovxwm zog) × 0.86÷ kub txawv

7, Tag nrho cov nqi cua sov QT = QS + QL

8, Cua txias: QT = 0.24 * ∝ * L * (h1-h2)

9, Qhov tseem ceeb ntawm cua sov cua txias: QS = Cp * ∝ * L * (T1-T2)

10, Cov cua kub cua txias: QL = 600 * ∝ * L * (W1-W2)

11,Dej khovntim:L/sV1 = Q1/(4.187△T1)

12, Cov dej txias txias: 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, Kev ua kom txias txias: EER = Lub peev xwm tub yees (Mbtu / h) / hwj chim noj (KW);COP = Cov tub yees muaj peev xwm (KW) / lub zog noj (KW)

14, Kev ua haujlwm txias ib nrab: NPLV = 1 / (0.01 / A + 0.42 / B + 0.45 / C + 0.12 / D)

15, Puv load tam sim no (peb theem): FLA = N / √3 UCOSφ

16, Cov huab cua ntshiab: Lo = nV

17. UASmuab Volume: L=Qs/〔Cp*∝*(T1-T2)〕

18, Lub zog kiv cua: N1 = L1 * H1 / (102 * n1 * n2)

19, Lub zog ntawm lub twj tso kua mis: N2 = L2 * H2 * r / (102 * n3 * n4)

20, Cov yeeb nkab txoj kab uas hla: D = √4 * 1000L2 / (π * v)

21, Cov kav dej: F = a * b * L1 / (1000u)