1. Heat Pumps For Energy Efficient / Economical Hot water Generation
5 Star hotel , Mumbai

2. 368 96% 25% Occupancy data 53.1% 53% Maximum Occupancy
Minimum Occupancy
96%
No of Guest Rooms
25%
368
Average Occupancy
53.1%
Heat Pump selection based on Average Occupancy of
53%
Based on data provided for
Aug 2014

3. Basic parameters at The Hotel
Average Gas consumption for Steam Boiler
Assumed Efficiency of boiler for Hot Water Generation through Steam
Net Calorific value of Natural Gas
Cost of Natural Gas
Cost of Power
To include steam generation for hot water & Laundry
1400 m³/day
70%
8500 kCal/m³
Rs. 30/m³
Rs. 12 /KW

4. 20° C 55° C For Guest Rooms Avg. Hot water consumption/day = 53 %
BASED ON AVG OCCUPANCY
53 %
For Guest Rooms
Avg. Hot water consumption/day =
Litres/day
Hot water temperature rise
20° C ° C
For Service Apartments
Avg. Hot water consumption/day =
4000 Litres/day
For Back of the House
Avg. Hot water consumption/day =
25000 Litres/ day
Total Hot Water Consumption = Say 55,000 Litres/day

5. STEAM/FUEL HEAT VS HEAT PUMP – OPERATIVE COMPARISON
Steam heated water
Rs 30/m³
Cost of Gas
Assumed Efficiency
70%
Heat transferred from steam to water
19,25,000 Kcal/day
= m³/day
Gas Consumed
Net calorific value
8500 kcal/m³
Heat pump
RS 12 /KW
Power cost
Water to be heated from
20°C °C
Heat Capacity of Hot Water in KW
2238 KW
Hot water heat load
55,000 x (55 – 20 ) = 19,25,000 kcal/day
Calculation:
19,25,000
0.7 x 8500
Calculation:
19,25,000 (Kcal)
860 (Kcal/KW)

6. Saving due to cooling benefit
Selection of heat pump
Heating capacity
200KW
Energy required in kW
2238 KW/day
Operating hours
11 hrs
Power Consumption
68 KW
132 KW (1 TR = kW)
Free Cooling
= 38 TR
Saving due to cooling benefit
38 TR x 0.75 kw/TR
28.5 KW
Net Power consumed
68 KW – 28.5 KW
39.5 kW

7. Weighted average cost of electricity
OPEX cost of heat pump
Net power consumed
Operating time
Weighted average cost of electricity
Rs 5,214 per day
39.5 KW
11 hrs/day
Rs 12/KW
Rs 18,77,040 per year

8. OPEX cost of Steam heated water
Gas consumption/day
Cost of Gas/m³
Rs 9,720 per day
324 m³/ day
Rs 30 / m³
Rs 34,99,200 per year

9. Savings in OPEX with Heat Pump
Operational cost of Gas fired boiler
Rs 34,99,200/yr
Operational cost of heat pump
Rs 18,77,040 /yr
Say Rs.16 Lakhs/year
Rs 16,22,160/year
Total Savings

10. CAPEX of heat pump system
Rs 13,50,000
Heat pump
Interface Accessories
Rs 12,50,000
Rs 26,00,000 /-
Total cost of heat pump system

11. Payback period in months
CAPEX of heat pump system x 12 Annual OPEX savings 26,00,000 x 12 16,00, months