Building Services 1 (BLD 60403)

HOT WATER SUPPLY SYSTEM (PART 1)

LECTURE OVERVIEW

1. Introduction

2. Types of hot water system

3. Electrical heating system

4. Solar heating system

1. INTRODUCTION

Thermodynamic process.

Using an energy source to heat water above its

initial temperature.

Domestic uses of hot water –cooking, cleaning,

bathing and space heating.

Industry, both hot water and water heated to

steam have many uses.

Traditionally:-

Domestically, water is heated in vessels known

as water heaters, kettles etc.

These metal vessels heat a batch of water but do

not produce a continual supply of heated water at

a present

Common energy for heating water:-

fossil fuels

natural gas

liquefied petroleum gas

oil or

sometimes solid fuels.

These fuels may be consumed directly or by the use

of electricity.

Alternative energy:-

solar energy

heat pumps

hot water heat recovering and

sometimes geothermal heating

usually in combination with backup systems

supplied by gas, oil or electricity.

Heat Recovering Unit

Solar Energy

Ground Source Heat Pump

Geothermal Heating

2. TYPES OF HOT WATER SYSTEM

The cost of heating water by electricity is more

expensive than heating by other fuels.

Care is required when installing electric water

heater in order to conserve heat.

3. ELECTRICAL HEATING SYSTEM

There are two types of electrical hot water system:-

i. Tank-less Water System (Instantaneous water

heaters)

ii. Storage systems

i) Tank-less Water Heating System:-

Also call instantaneous.

Provide continuous flow, instant on water heaters.

Give instant hot water day or night.

Instantly heat water as it flows through the device

Do not retain any water internally.

Water for tank-less heater obtainable in the

following:-

Sink heaters – single or multi-point to serve sink

or basin.

Bath heaters – a swivel spout can serve a wash

basin in addition to the bath.

Boiling water heaters – provide hot water or

boiling water for making drinks.

Multiple heaters – provide sufficient hot water to

bath, sink, basin or may be used in larger

building.

Tank-less Heater

Advantages of Tank-less Water Heating System

Long term energy savings

Cost more initially, but, result cost saving and energy

saving in long term.

Water is heated only when it is needed

No storage of hot water.

Unlimited hot water

Less Physical space

Can be mounted on a wall or even internally in a

building’s structure.

Take up less space than a tank type water heater.

Reduced risk of water damage

No risk of water damage from a tank failure.

Risk or water damage from a pipe or fitting failure

remains.

Disadvantages of Tank-less Water Heating System

× Start-up delay

longer wait to obtain hot water.

× No operation with low pressure

Very much reliant on the water pressure that is

delivered to the property.

ii) Storage System:-

Storage System Water Heater

Storage system:-

Advantages of Storage System

High flow rates

Power shower capability

Low maintenance costs

Less risk of being without supply

Disadvantages of Storage System

× Pre heat hot water needed.

× Hot water require recovery time.

× Storage space needed.

× Risk of pipes freezing in winter.

4. SOLAR HEATING SYSTEM

Water heated by the use of solar energy.

Composed of:-

solar thermal collectors

a water storage tank

interconnecting pipes and

a fluid system to move the heat from the collector to

the tank.

Solar collector typically 3-6m2 in area

Standard package with appliances.

Solar Panel System

Solar Heating In Malaysia

Malaysia has a high solar energy potential

(monthly average daily sunshine duration

ranging from 4 hr to 8 hr.)

Clean energy of tomorrow.

Solar energy or solar photovoltaic.

Attractive incentive to encourage usage of solar

energy.

Advantages of Solar Water Heating System

Safety - No gas leak, no dangerous explosion, no

electricity mishaps. Safe

Savings - No electric bills, no gas bills – the

product pays for itself.

Convenient - Rain or shine. Enjoy a hot shower

any time of the day.

Comparison of Electrical Water Heater & Solar Water Heater

THANK YOU

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Teacher: No, Millie…….. Always say “I am…”

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