Heat Pump, TUV Techindo, Bali 18-19 juli 2013

Hot Water Management

How to Save Energi via Hot Water Management

Ir. Herry Widjanarko MBA MSIE

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


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


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


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


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


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


Source of hot water

• Chiller

• Boiler

• Water Heater;– Electric– Solar– Gas– Heat Pumps


Types of Water Heater


Cost to heat up water up to 55 4C

* 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


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


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


How Heat Pump Work 1

Evaporator

Expansion Valve

Compressor

Heat Pump Water HeaterWork Cycle

Water Heat

Exchanger


How Heat Pump Work 2

Evaporator

Expansion Valve

Compressor

Heat Pump Water HeaterWork Cycle

Water Heat

Exchanger

Pumps

Hot Water 55 C


Types Heat Exchanger

☺ Double wall pipes

☺ Tanks with pipes

☺ Titanium tubes


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


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


Example Heat Pump COP


Heat Pump Design

• Individual

• Individual combined with solar water heater

• Central system

• Central system combined with solar water heater


Central vs. Individual

Consideration factor:

• Location and distance

• Frequency of usage

• Technical space possibilities

• Cost of investment

• Cost of operations


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


Sample IndividualPipa 1"

Pipa 1/2"

Pipa 3/4"

Sistem Air Dingin Rumah

Use of natural convention to circulate hot water


Sample Individual with Solar Water heater

Sistem Air Dingin Rumah


Combined System WorkSolar Panel

Evaporator Solar Panel


Evaporator

Solar Panel



Evaporator

Start Night Night Morning

Afternoon Dawn Night


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


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)


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)


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)


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


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


Example of System

Hot Water Tank Hot Water Tank

Heat Pump53ºC

Heat Pump53ºC

Heat Pump53ºC

Pump

Pump

User

Heat Pump51ºC

Circulation with separate system

Pump


Example of System

Hot Water Tank

Heat Pump55ºC

Heat Pump55ºC

PompaPompaPompa

Cold Water Tank


Example of System

Pompa

Hot Water TankHot Water Tank Hot Water TankHot Water Tank

Heat Pump50ºC

Pompa

Heat Pump50ºC

Pompa

Heat Pump50ºC

Pompa


Example of System

Hot Water Tank

Heat Pump55ºC

Heat Pump55ºC

PompaPompaPompa

Cold Water Tank

Hot Water Tank Solar Panel

Pompa


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.


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.


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.


Date post:	14-Jan-2015
Category:	Technology
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