NUEVA VIZCAYA STATE UNIVERSITY
Bambang Campus
Bambang, Nueva Vizcaya
COLLEGE OF ENGINEERING
Mechanical Engineering Department
REPORT OUTLINE IN ALTERNATIVE ENGINEERING RESOURCES
TOPIC: SOLAR WATER HEATING
Prepared by: GROUP 3
DICCION, LOVELYN M.
DONTOGAN, JERBOY B.
UBINA, IVY JOY A.
DATE SUBMITTED: DECEMBER 13, 2019
ENGR. LARRY P. REMOLAZO
FACULTY
I. INTRODUCTION
A basic use of solar energy is for heating the fluids of air and water. For,
instance, houses in cold and temperate climates often need heated air for comfort, and
in all countries hot water is beneficial for personal and clothes washing as well as for
other domestic services. There are several needs in business, industry, and agriculture.
The general principle and analysis of solar water heaters apply also to many
systems which use active and passive mechanisms to absorb solar energy as heat.
The manufacture of solar water heaters has become an established industry in
several countries, especially China, Australia, Germany, Greece, Brazil, Israel, and
Japan.
II. BODY
BENEFITS OF USING WATER HEATING SYSTEM
• Help reduce harmful emission from fossil fuels.
• You can enjoy free energy from the sun, which could save your energy cost in
heating water.
BASIC COMPONENTS OF SOLAR WATER HEATING
1. Solar Collectors
mounted on roof to capture solar radiation
2. Storage Tank
holds the solar heated water
3. Interconnecting Pipe Work
carry the heat transfer liquid
COMMON TYPES OF SOLAR WATER HEATING SYSTEM
• Active
uses an electric pump to circulate water or a heat transfer fluid from
storage tanks through the collectors.
• Passive
relies on gravity and the tendency for water to naturally circulate as it is
heated, allowing water or heat transfer fluid to move through the system
without the use of a circulating pump.
ISSUES TO BE CONSIDERED WHEN INSTALLING SOLAR WATER HEATING
SYSTEM
• Solar collectors’ orientation
• Application of solar water heating systems
• Retrofitting of solar water heating system
• Market availability
• Maintenance and expected life
TWO TYPES OF SOLAR COLLECTORS
1. FLAT-PLATE COLLECTORS
It is the simplest type.
It consists of copper tubes fitted to flat absorber plates.
Typically, the tube diameter is ~2 cm, the tube spacing ~20 cm and the
plate thickness ~0.3 cm.
Its assembly is contained within an insulated box, and covered with
tempered glass.
They are typically size to contain 40 gallons of water.
2. EVACUATED COLLECTORS
One method for moderate improvement of a flat-plate collector is to use
‘double-glazing’
Best method is to evacuate the space between the plate and its glass
cover
SYSTEMS WITH SEPARATE STORAGE
1. ACTIVE SYSTEMS WITH FORCED CIRCULATION
• A common type of solar water heater in Australia.
• The glass-covered flat-plate collector heats water for the insulated storage tank
placed above (hot water rises).
• A back-up electric heater in the tank is available for the rare occasions when
solar input is insufficient.
2. SYSTEMS WITH THERMOSYPHON CIRCULATION
• Collector and storage tank with thermosyphon circulation
• The water circulation in a roof-top unit, is driven by the density difference
between hot and cold water.
SELECTIVE SURFACES
1. Ideal
2. Metal semiconductors composite surface
3. Manufacture of selective surfaces
INSTRUMENTATION AND MONITORING
• Display of temperatures.
• Temperature sensors (usually thermistors) for the display: collector outlet, top of
the tank, bottom of the tank, bottom of the collector and middle of the tank.
• Pump-enabled on/off colored lights.
• Pump hours run.
• Back-up heating on (especially important for electric immersers for which sensors
and time clocks may fail or be mistimed, and so unnecessary electricity is used).
FAULTS (AND REMEDIAL ACTIONS) THAT MAY OCCUR DURING THE LONG
LIFETIME OF A SOLAR WATER HEATER INCLUDE THE FOLLOWING:
• Dirty cover glass (inspect at least twice per year and if necessary clean; note
that self-cleaning glass may be used).
• Pump failure (indicated by temperature difference across the collector being too
large).
• Sensor failure (often mice and rodents nibble the cables!).
• Fuses blown (not itself a fault, but indicates a probable fault).
• Frozen and burst pipes (inadequate insulation and/or bad positioning).
• Metal corrosion from poor design using mixed metals (should not occur with
reliable design; annual inspection recommended with remedial action if
necessary).
SOCIAL AND ENVIRONMENTAL ASPECTS
• Solar water heating is an extremely benign and acceptable technology.
• Installations may be expected to be effective with very little service cost for at
least 25 to 35 years.
• Units designed for colder climates with the threat of freezing conditions are more
sophisticated and expensive than those made for countries where freezing does
not occur.
• In almost all cases, using solar energy for water heating replaces brown (fossil)
energy at source, this gives the benefits of improved sustainability and fewer
greenhouse gas emissions.
III. CONCLUSION
Solar water heaters are a widely used and straightforward application of solar
energy, in use in over 200 million households worldwide. There are relatively few homes
and businesses that would not benefit from such installations, yet their use is still far
from universal. Most systems use glazed, non-concentrating collectors, which typically
raise the water temperature to 30 to 60 degrees Celsius above ambient temperature,
depending on isolation and flow rate. The performance of such collectors may be
estimated using standard formulae of heat transfer. The general principles and analysis
that apply to solar water heaters apply also to many other systems that use active and
passive mechanisms to absorb the Sun’s energy as heat. Selective surfaces and
evacuated collectors enhance the performance of collectors at acceptable cost.
