ALTORATH INTERNATIONAL ENGINEERING CONSULTANT,Abu Dhabi,UAE.
11P22-027 - Seed Conservation
Made By : RAVI KIRAN Date : 04/01/2023 Project :
Main Building
Checked By : Date : Contract : Sheet No. : Page 1 of 10
Revised By : Date : Section : Plumbing Calc.N0. : 1
Checked By : Date : Job No. : 11P22-027 File : P:\2022\11P22-027 - Seed Conservation\4_Engineering\4.6_Mechanical\4.6.4_Detailed\4.6.4.3_Calculations\Water supply\
Subject : ELECTRIC HOT WATER HEATER SIZING
1) INTRODUCTION
Hot water will be generated by means of Individual Electric Water Heater.
2) Electric Water Heater Sizing
Hot Water Demand and Fixture values were extracted from 1998 ASHRAE Applications
Handbook Chapter 48, Table 9
3) As Per Specifications:
o
a) Storage Temperature : 60 C
b) Hot water recovery period : 3 Hours
4) Assumptions
o
Minimum incoming water temperature : 15 C
ALTORATH INTERNATIONAL ENGINEERING CONSULTANT,Abu Dhabi,UAE.
11P22-027 - Seed Conservation
Made By : RAVI KIRAN Date : 04/01/2013 Project :
Main building
Checked By : Date : Contract : Sheet No. : Page 2 of 10
Revised By : Date : Section : Plumbing Calc.N0. :
Checked By : Date : Job No. : E1M File : P:\2022\11P22-027 - Seed Conservation\4_Engineering\4.6_Mechanical\4.6.4_Detailed\4.6.4.3_Calculations\Water supply\
Subject : 5) ELECTRIC HOT WATER HEATER SIZING (EWH-01)
Area Served : GF-11-Female Toilet
Design Criteria :
o
Final Water Temperature : 60 C
o
Incoming Water Temperature : 15 C
Recovery Time : 3 Hour Recovery
From 1998 ASHRAE Applications Pg 48.16 Table 9
Occupancy Type : Office Building
Demand Factor : 0.3
Storage Factor : 2
Fixture Served Unit ( L/hr ) Fixture Qty Total ( L/hr )
Shower 114 1 114
Lavatory Private 7.6 4 30.4
Possible Maximum Demand 145
Probable maximum demand = 145 x 0.3
= 44 L/hr
ALTORATH INTERNATIONAL ENGINEERING CONSULTANT,Abu Dhabi,UAE.
11P22-027 - Seed Conservation
Made By : RAVI KIRAN Date : 04/01/2013 Project :
Main building
Checked By : 0 Date : Contract : Sheet No. : Page 3 of 10
Revised By : Date : Section : Plumbing Calc.N0. : 1
Checked By : Date : Job No. : File : P:\2022\11P22-027 - Seed Conservation\4_Engineering\4.6_Mechanical\4.6.4_Detailed\4.6.4.3_Calculations\Water supply\
Subject : 5) ELECTRIC HOT WATER HEATER SIZING (EWH-01)
Storage Tank Capacity
Storage tank capacity = 44 x 2
88 Lts
Total Recovery Rate (m in L/s)
For 3 Hour the Recovery Rate m is = Storage Capacity in Lts / Recovery Time in Sec.
= 88 / 3 x 3600
= 0.0082 L/s
Total Power Rating for Water Heater
Q = m x r x Cp x Dt = 0.0082 x 1.0 x 4.187 x 45
= 1.55 kW
where:
Q= kW (Heater Input)
m = 0.0082 L/s (Recovery Rate from above)
r = 1.00 Kg/l (Density of Water)
Cp = 4.187 KJ/(Kg.K)
Dt = 45.00 oK (Temperature rise)
Water Heater Selection
Requirements (From Above) : 1 Nos 88 Lts 1.55 kW
Using Standard WH size of : = 80 Lts
Select : 1 Nos 80 Lts 1.5 kW
