Calculation for 9000 Gallons Roof Tank Cooling System

Description

In Summer

Tank Volume, Gallons 9000 (34,000 lits)

Water Temperature Required 28 deg C/

Incoming Water Temperature 43 deg C

Desired Temperature Difference 15 oC

Formulae

Q = m x Cp x (T2-T1)

Cooling Capacity kW = Volume of Water lits x Sp x (T2-T1) oC / 860 x T

Sp, Specific heat of water = 1.0 Kcal / Kg. x oC

T, initial cooling period = 6 hours

COOLING LOAD

T2 (Incoming water temp.) = 43 o C

T1 (reqd. water temp.) = 28 o C

T2-T1 = 15o C

Therefore, kW = 34,000 x 1 x 15/ 860 x 6

= 98.85 kW

To cool in 6 hour, TR = 28.25 Tons (98.85 kW)

Note:

Total water flow rate can be calculated by = Total tank volume / cooling time i.e. 34000/6 = 5667 Lit/hr

Units suggested 2 units of 50 kW each with flow 2.9 m3/hr and T 15C.

Calculation for 16000 Gallons Roof Tank Cooling System

Description

In Summer

Tank Volume, Gallons 16000 (60,600 lits)

Water Temperature Required 28 deg C/

Incoming Water Temperature 43 deg C

Desired Temperature Difference 15 oC

Formulae

Q = m x Cp x (T2-T1)

Cooling Capacity kW = Volume of Water lits x Sp x (T2-T1) oC / 860 x T

Sp, Specific heat of water = 1.0 Kcal / Kg. x oC

T, initial cooling period = 6 hours

COOLING LOAD

T2 (Incoming water temp.) = 43 o C

T1 (reqd. water temp.) = 28 o C

T2-T1 = 15o C

Therefore, kW = 60,600 x 1 x 15/ 860 x 6

= 176.20 kW

To cool in 6 hour, TR = 50.50 Tons (176.50 kW)

Note:

Total water flow rate can be calculated by = Total tank volume / cooling time i.e. 60,600/6 = 10,100 Lit/hr

Units suggested 2 units of 80 kW each with flow 4.6 m3/hr and T 15C.