TUV Techindo seminar of Eco Hotel, Hot Water Management, Bali 18-19 Juli 2013

1. Hot Water Management
How to Save Energi via Hot Water Management
Ir. Herry Widjanarko MBA MSIE

2. RHEMS, Bali 18-19 July 2013
Topics
• Hot Water Management;
– Loss of heat
• Water leakage
• Less Insulation
• Not optimal design system
– Source of hot water
• Comparison of types and energy usage
• Heat pumps principles

3. RHEMS, Bali 18-19 July 2013
Loss of Heat
• Loss of heat, sometimes missed from the
calculation of energy saving, where the loss
means more energy to be wasted.
• The cost to stop or prevent the heat some times
expensive and not possible
• Possible loss of heat is due to; hot water
leakage, less insulation and most important the
design of the system

4. RHEMS, Bali 18-19 July 2013
Hot Water Leakage
• More water to be heat up
• Waste of water and energy
• Reduce cleanness
• Could be solved if detected;
– Run pressure test
– Check the whole piping and valve

5. RHEMS, Bali 18-19 July 2013
Insulation
• High investment cost vs. loss of heat
• Significant in certain area of piping
• Old system;
– Not all have possible to be insulated
– High cost to replace
• New system;
– Possible to implemented in all areas
– Relative lower cost than at old system

6. RHEMS, Bali 18-19 July 2013
System Design 1
• Point to consider:
– No perfect insulation exist
– High investment, low operating cost vs. low
investment, high operating cost
– Space limitation
– Technology or industrial availability limitation

7. RHEMS, Bali 18-19 July 2013
System Design 2
• Point to achieve:
– Reduce open surface area
– Reasonable investment, lowest operating
cost.
– Optimum space
– Use all physics principles and not against
– Push hot water in design of tanks, heat-up
from lowest temperature possible

8. RHEMS, Bali 18-19 July 2013
Source of hot water
• Chiller
• Boiler
• Water Heater;
– Electric
– Solar
– Gas
– Heat Pumps

9. RHEMS, Bali 18-19 July 2013
Types of Water Heater

10. RHEMS, Bali 18-19 July 2013
Cost to heat up water up to 55 C̊
* Tarif non subsidi hanya berlaku di luar listrik, tarif listrik industri diatas 200KVA
kwh m3 kwh kg kwh
10.00 2.08 48.90 5.60 17.50
kwh kg kwh liter kwh
10.00 1.87 48.90 4.54 17.50
864.00 5,850.00 864.00 4,500.00 864.00
864.00 9,000.00 864.00 10,000.00 864.00
8,640.00 16,848.00 42,249.60 45,360.00 15,120.00
Tarif Indonesia *
Tarif yang berlaku buat Industri
Biaya Energi Pemanas (Rupiah)
Satuan
Satuan di Indonesia

11. RHEMS, Bali 18-19 July 2013
Heat Pump Principles
• The most energy saving after solar power
• No dependent with weather
• Heat when needed, no need big tanks
• Flexible design
• No danger of burning and electric shock

12. RHEMS, Bali 18-19 July 2013
How Heat Pump Work
• Use heat (entropy) in air as main energy
to heat the water
• Electricity is only use to transfer the heat
from air (water) to water, this make the
system very low usage of electricity
• Lower the temperature of air

13. RHEMS, Bali 18-19 July 2013
How Heat Pump Work 1
E
v
a
p
o
r
a
t
o
r
Expansion
Valve
Compressor
Heat Pump
Water Heater
Work Cycle
Water
Heat
Exchanger

14. RHEMS, Bali 18-19 July 2013
How Heat Pump Work 2
E
v
a
p
o
r
a
t
o
r
Expansion
Valve
Compressor
Heat Pump
Water Heater
Work Cycle
Water
Heat
Exchanger
Pumps
Hot Water 55 C

15. RHEMS, Bali 18-19 July 2013
Types Heat Exchanger
☺ Double wall pipes
☺ Tanks with pipes
☺ Titanium tubes

16. RHEMS, Bali 18-19 July 2013
Heat Exchanger
Exchange heat from refrigerant to water
- Water force flow or natural flow (tanks with
pipe of refrigerant)
- The flow of water must be correct to
absorb heat optimum
- COP in natural flow is smaller than force
flow

17. RHEMS, Bali 18-19 July 2013
COP
• The heat pump efficiency is called COP
• The higher value the better
• It depends on:
– Water inlet temperature
– Ambient air temperature
– Target of heating temperature

18. RHEMS, Bali 18-19 July 2013
Example Heat Pump COP

19. RHEMS, Bali 18-19 July 2013
Heat Pump Design
• Individual
• Individual combined with solar water
heater
• Central system
• Central system combined with solar water
heater

20. RHEMS, Bali 18-19 July 2013
Central vs. Individual
Consideration factor:
• Location and distance
• Frequency of usage
• Technical space possibilities
• Cost of investment
• Cost of operations

21. RHEMS, Bali 18-19 July 2013
Individual
• Location among point of hot water outlets
far each other, like cottages types
• Cost to keep hot water in pipe is high due
to insulation or high loss of heat
• Low frequency of usage

22. RHEMS, Bali 18-19 July 2013
Sample Individual
Pipa 1"
Pipa 1/2"
Pipa 3/4"
Sistem Air
Dingin Rumah
Use of natural
convention to
circulate hot
water

23. RHEMS, Bali 18-19 July 2013
Sample Individual with
Solar Water heater
Sistem Air
Dingin Rumah

24. RHEMS, Bali 18-19 July 2013
Combined System Work
Solar
Panel
Evaporator Solar
Panel
Evaporator Solar
Panel
Evaporator
Solar
Panel
Evaporator Solar
Panel
Evaporator Solar
Panel
Evaporator
Start Night Night Morning
Afternoon Dawn Night

25. RHEMS, Bali 18-19 July 2013
Central Heat Pump Design
System
• Total water per day
• Peak hours (50% needs in 2 hours)
• Tank and Heater composition (heat pump is less
electricity, so turn on when needed)
• Losses, circulating distribution, insulation
• Heat Transfer efficiency, high degree, high
energy, low degree, low energy, no double job or
heating-cooling, steady/stable temperature

26. RHEMS, Bali 18-19 July 2013
Point to consider
• PLN cost based on usage and no more
capacity cost
• Source of cold water
• Open tanks or pressure tanks (close)
• Single system or multiple (based on
section)

27. RHEMS, Bali 18-19 July 2013
Tank Consideration
• Low volume capacity to avoid heat loss
• Have cold water back-up tanks
• Design to make hot water flow first
• Price of tank is comparable with the heat
pump, better use more heat pump than
big tanks
• Close tank (pressure tank) rather than
open tank (high heat losses)

28. RHEMS, Bali 18-19 July 2013
Heat Pump Capacity
• Possible to supply during peak hours to
avoid big tanks (able to fulfill the
requirement within 1 hours of designed
capacity of needed water, comparable
with max flow capacity)
• Low electricity power input makes possible
to have just in time principle (no more PLN
hidden fee)

29. RHEMS, Bali 18-19 July 2013
Choosing Heat Pump
• Well made from real factory
• Capable run 50% per day without damaged
• Sensitivity of temperature sensor about 2 ̊ C, the
arrangement of the sensor is critical issue
• Design by people who understand heat pump,
eco-industry, energy saving
• Consider investment vs. operational cost and
electricity capacity

30. RHEMS, Bali 18-19 July 2013
Circulating Water
• The circulating hot water in piping system
can use separate heat pump instead of
main heat pump, can be lower than the
main system to reduce energy
• Reduce the use of water, people intend to
flow the water until feel hot/warm

31. RHEMS, Bali 18-19 July 2013
Example of System
Hot Water Tank Hot Water Tank
Heat
Pump
53ºC
Heat
Pump
53ºC
Heat
Pump
53ºC
Pump
Pump
User
Heat Pump
51ºC
Circulation with
separate system
Pump

32. RHEMS, Bali 18-19 July 2013
Example of System
Hot Water Tank
Heat
Pump
55ºC
Heat
Pump
55ºC
PompaPompaPompa
Cold Water Tank

33. RHEMS, Bali 18-19 July 2013
Example of System
Pompa
Hot Water TankHot Water Tank Hot Water TankHot Water Tank
Heat
Pump
50ºC
Pompa
Heat
Pump
50ºC
Pompa
Heat
Pump
50ºC
Pompa

34. RHEMS, Bali 18-19 July 2013
Example of System
Hot Water Tank
Heat
Pump
55ºC
Heat
Pump
55ºC
PompaPompaPompa
Cold Water Tank
Hot Water Tank
Solar
Panel
Pompa

35. RHEMS, Bali 18-19 July 2013
Pay Back Period
• Compare with others methods the
operation cost of heat pumps is about
30%-50% less than other methods.
• Pay back period period compare with
heating element water heater in every
room is less than 1 year.

36. RHEMS, Bali 18-19 July 2013
Investment Cost
• Compare with heating element, the
investment cost is about 1.5 - 2 times
higher but the operational cost is about 1/3
or 1/4 of the cost.

37. RHEMS, Bali 18-19 July 2013
Price Tanks vs. Heat Pump
• The price of heat pump is about 2 times of
the tank capacities.
• Heat pump with capacities 40 kw or about
1250 liter per hour (Jakarta condition) is
about equal with price of tank with 2500
liter capacities.

38. RHEMS, Bali 18-19 July 2013