# Variables
DBTo = 10.; #Out door Dry bulb temperature in oC
WBTo = 8.; #Out door Wet bulb temperature in oC
DBTi = 20.; #In door Dry bulb temperature in oC
RH = 0.6; #Re-Heat factor
a = 0.3; #amount of air circulated in (m**3)/min/person
S = 50.; #Seating capacity of office
BPF = 0.32; #ByPass factor
ha = 25.; #Enthalpy at point a from Psychrometric chart shown in Page 346 in kJ/kg
hb = 42.5; #Enthalpy at point b from Psychrometric chart shown in Page 346 in kJ/kg
hc = 42.5; #Enthalpy at point c from Psychrometric chart shown in Page 346 in kJ/kg
Wa = 0.006; #Specific humidity at point a from Psychrometric chart shown in Page 346 in kg/kg dry air
Wc = 0.009; #Specific humidity at point c from Psychrometric chart shown in Page 346 in kg/kg dry air
Tb = 27.; #Temperature at point b in oC
na = 0.81; #Specific Volume from Psychrometric chart shown in page 346 in (m**3)/kg
# Calculations
ma = (a*S)/(na*60); #mass of air circulated per second in kg/s
Hc = ma*(hb-ha); #Heating capacity of coil in kW
Ts = (Tb-(BPF*DBTo))/(1-BPF); #Heating coil surface temperature in oC
C = (ma*3600)*(Wc-Wa); #Capacity of humidifier in kg/hr
# Results
print 'Heating capacity of coil is %3.2f kW \
\nSurface temperature of coil is %3.0f C \
\nCapacity of humidifier is %3.2f kg/hr'%(Hc,Ts,C)
# rounding off error
# Variables
S = 60.; #No. of staff
DBTo = 30.; #Out door Dry bulb temperature in oC
RHo = 0.7; #Re-Heat factor at out-door
a = 0.4; #amount of air circulated in (m**3)/min/person
DBTi = 20.; #In door Dry bulb temperature in oC
RHi = 0.6; #Re-Heat factor at indoor
Td = 25.; #Heating coil surface temperature in oC
ha = 82.5; #Enthalpy at point a from Psychrometric chart shown in Page 347 in kJ/kg
hb = 34.5; #Enthalpy at point b from Psychrometric chart shown in Page 347 in kJ/kg
hc = 42.5; #Enthalpy at point c from Psychrometric chart shown in Page 347 in kJ/kg
Wa = 0.020; #Specific humidity at point a from Psychrometric chart shown in Page 347 in kg/kg dry air
Wb = 0.009; #Specific humidity at point b from Psychrometric chart shown in Page 347 in kg/kg dry air
Tb = 12.; #Temperature at point b in oC
na = 0.89; #Specific Volume from Psychrometric chart shown in page 346 in (m**3)/kg
# Calculations
ma = (a*S)/(na*60); #mass of air circulated per second in kg/s
Hc = (ma*(ha-hb))/3.5; #Heating capacity of cooling coil in tonnes
Hh = ma*(hc-hb); #Heating capacity of heating coil in kW
W = (ma*3600)*(Wa-Wb); #Amount of water vapour removed per hour in kg/hr
BPF = (Td-DBTi)/(Td-Tb); #By-Pass factor
# Results
print 'Capacity of cooling coil is %3.2f tonnes \
\nCapacity of heating coil is %3.1f kW \
\nAmount of water vapour removed per hour is %3.2f kg/hr \
\nBypass factor is %3.3f'%(Hc,Hh,W,BPF)
# Variables
RSH = 10.; #Room sensible heat in kW
RLH = 10.; #Room latent heat in kW
td1 = 25.; #Inside temperature in oC
RH1 = 0.5; #Inside Re-Heat factor
h1 = 50.4; #Enthalpy at point 1 in kJ/kg
td2 = 35.; #Out door Dry bulb temperature in oC
tw2 = 28.; #Out door Wet bulb temperature in oC
CR = 4.; #Cooling coil ratio
BPF = 0.1; #Cooling coil bypass factor
tADP = 10; #Apparatus dew point temperature in oC
RH3 = 0.55; #Re-Heat factor at point 3
h3 = 58.2; #Enthalpy at point 3 in kJ/kg
RH4 = 0.95; #Re-Heat factor at point 4
h4 = 32.2; #Enthalpy at point 4 in kJ/kg
RH5 = 0.81; #Re-Heat factor at point 5
h5 = 36.8; #Enthalpy at point 5 in kJ/kg
RH6 = 0.54; #Re-Heat factor at point 6
h6 = 43.1; #Enthalpy at point 5 in kJ/kg
td6 = 22.; #Temperature at point 6 in oC
# Calculations
td3 = ((td2-td1)/5)+td1; #Temperature at point 3 from Psychrometric chart shown in Page 348 in oC
td4 = (BPF*(td3-tADP))+tADP; #Temperature at point 4 from Psychrometric chart shown in Page 348 in oC
td5 = td4+((td1-td4)/5); #Temperature at point 5 from Psychrometric chart shown in Page 348 in oC
RSHF = RSH/(RSH+RLH); #Room Sensible Heat Factor
QR = h1-h6; #Total heat removed in kJ/kg
S = (RSH+RLH)/QR; #Supply air quantity in kg/s
R = (S*(h6-h5))/3.5; #Refrigeration load due to reheat in ton
D = (S*4)/5; #Dehumidified air quantity in kg/s
T = (D*(h3-h4))/3.5; #Total refrigerating capacity in ton
Q = (D/5)/1.2; #Quantity of fresh air supplied in (m**3)/s
# Results
print 'Supply air condition to the room is %3.2f kg/s \
\nRefrigeration load due to reheat is %3.2f ton \
\nTotal refrigerating capacity is %3.2f ton \
\nQuantity of fresh air supplied is %3.3f m**3/s'%(S,R,T,Q)