| |
Q. 1 |
How does the Solar Water Heating System
heat water?
|
Ans 1 |
The main part of the Solar Water Heating
System is the Flat
Plate Collector or in common parlance “PANEL”. Metallic
strip (mainly
of Copper) is coated with thin layers of Nickel and Chromium, which
is
called as Solar Selective Coating. This selective coating ensures
highest degree of absorption of Solar Heat and least possible emission
of the same. This results in optimal utilization of the Solar Heat.
This
component, which is the heart of any Solar Heating System, is known
as Absorber Fin.
In every Flat Plate Collector (panel) there are number of such absorber
fins,
which are connected on both sides to copper pipes known as headers.
The
heat collected by the Absorber Fin is transferred to the liquid flowing
through
the tubes / pipes. The liquid so heated becomes lighter & is pushed
up by the
cold water at the bottom helping it fill the Hot Water Storage Tank.
Thus the
cold water is continuously heated and collected in the Hot Water Storage
Tank
throughout the day. This is on the basis of natural thermo-siphon.
|
Q. 2 |
Whether the water heated during day remains
hot throughout the night?
|
Ans 2 |
The Solar Flat Plate Collector is provided
with insulation, which prevents heat loss.
Similarly the Hot Water Storage Tank and the pipes carrying water
upto user point
are also properly insulated. This ensures minimum drop in the temperature
of the
hot water. As a result, you get hot water even on cold mornings.
|
Q. 3 |
What are the applications of SWHS?
|
Ans 3 |
The main use of hot water is for bathing.
It is also used for
washing of clothes and utensils to help less consumption of soap and
detergent to get rid of stubborn dirt and grime. To cleanse floors
and
disinfect surroundings with added dermicides. It can also be used
for
preheating to save fuel and electricity to raise the temperature of
normal
or below normal cold water. The Users could be Homes, Hospitals,
Hotels, Hostels, Industries, Laboratories, Laundries etc…
|
Q. 4 |
What is the difference between Solar
Water Heating System and a
metal utensil?
|
Ans 4 |
Metal utensil gets heated in the sun
but due to the emission of
heat gets cooled fast. Heart of the Solar Water Heating System, THE
ABSORBER due to the selective coating results in absorption of
maximum heat and loss of minimum heat due to emission. As a result
the heat is retained effectively in the Solar Water Heating System
as
compared to any other uncoated Metal. This confirms that the efficiency
of Solar Water Heating System depends mainly on the quality of
the absorber used.
|
Q. 5 |
Why are there complaints about the poor
performance of Solar Water
Heating System? What are the reasons?
|
Ans 5 |
There can be various reasons for poor
performance of Solar Water
Heating System such as
a) The most important reason - low quality absorber.
b) The collectors are not installed properly to suit the latitude
of your city. Dealers / installers lacking required technical knowledge
about Solar Energy, not following the standards and having purely
commercial attitude are responsible for this. Please ensure that dealer
/ installer has required knowledge.
c) We being in the Northern Hemisphere, Sun is in the south most of
the critical time. So the panels must be installed facing SOUTH
to gather maximum heat.
d) Care is not taken to ensure that the hot water does not get mixed
with the cold water.
e) Solar Water Heating System is of inadequate capacity. (Undersized
System.)
f) Continuous use of hot water over long period.
g) Lack of adequate shadow free space for installation.
h) Use of hard water having dissolved salts beyond acceptable limit
causing scaling and retardation of heat transfer process.
i) Inadequate head for the cold water storage tank resulting in
sluggish circulation.
j) Inadequate capacity cold water storage tank.
k) Poor quality insulation of storage tank and pipes.
l) Blockage of system due to sediments in the water.
m) Panel top glass not clean, affecting Solar Transmittance.
|
Q. 6 |
What are the benchmarks for selecting
a Solar Water Heating system as there are number of manufacturers
and dealers?
|
Ans 6 |
Unfortunately today there is a plethora
of manufacturers and dealers without required technical know-how and
having no scruples, do it as a business as there is a good demand
for Solar Equipments. These elements prosper due to total lack of
information with the common man about the criterion for selection
of good Solar Water Heating System. Similarly the habit of customers
to give more weightage to only the price factor, without considering
the technical features and life expectancy of the system, lands them
with a poor quality system. Sometimes absence of adequate after sales
service results in the entire investment getting wasted.
Solar energy is inexhaustible. Similarly Solar Water Heating System
is a thing which one should have to buy once in a lifetime. Thus while
selecting a Solar Water Heating System, one MUST evaluate the following
factors before taking a decision.
1. Make of the panel. (By whom it is manufactured)
2. Which absorber is used in the panel? Whether the sheet and tube
are welded / soldered or brazed together? Best results are obtained
by TIG welded full length joint than any other method. To have the
best ask for AKSON’S PVD Sunselect (TM) COATED absorber.
3. Construction of collector box. Check whether the gaskets and grommets
are of EPDM.
4. The Hot Water Storage Tank. Ask for only Stainless Steel (SS 304/
316 Grade), as it will mean service for lifetime. Ensure that the
pipefittings attached to the tank are also of SS 304/316 and are TIG
welded. Some vendors tell interesting stories for selling systems
with tanks of Mild Steel or even give SS tanks of inferior quality
SS and non-SS fittings. These are normally the tactics used for showing
a low price. Storage tanks other than of SS 304 of adequate thickness
will tend to rust and may need a replacement after 4- 6 years costing
around Rs. 6000/ for a 125 Ltrs. tank to be replaced by SS tank apart
from the mental tension and running around. Some manufacturers use
SS 202 grade, which is the Steel used normally for kitchen utensils.
If this is used for tank, the tank can develop cracks any time. Some
manufactures use SS 304, which is the ideal grade but use low thickness
sheet. Similarly the fittings also should be of SS 304 grade. Some
manufacturers use GI Fittings. Since the GI to SS welding is not proper
the tank starts leaking after some time.
5. Some manufacturers use inadequate / improper insulation for hot
water tank. This results in water temperature getting substantially
reduced over night. The insulation should be adequate. For hot water
tank the cladding after insulation should be of high grade Aluminium.
It should be without joints. The round cover on both sides should
be of aluminium and without joints. Plastic/ Fiberglass degenerates
after 4-5 years. If there is a joint, cold air enters inside and brings
down the temperature of the water.
6. The hot water pipe should be insulated with good quality insulation
material.
7. If the piping is to be done by the seller, the pipes and fittings
of reputed companies having a name for quality product should be insisted
upon.
8. Valves should be of good quality with life long ease of operations.
9. Hot water tank should have a facility (socket) for fitting electrical
heater.
10. Services the seller offers during the Guarantee Period should
be examined. |
Q. 7 |
How to install a solar heating system
properly? What conditions should be fulfilled for it?
|
Ans 7 |
Solar system should be installed with
the panel at particular angle from the floor attitude/latitude of
the city.
Panel should have proper & sturdy support on both sides. The entire
system should be properly installed on the terrace/ platform. The
installation of piping should start from collector side so that unnecessary
pull and stress in avoided on that side. The collector should be installed
on the southwest corner of the terrace with a slope on the south side.
The collector of the solar water heating system should be receiving
the sun light minimum for 5.5hours per day. The cold water should
be on minimum 2.5-meter elevation from bottom of the panel. Proper
vent should be provided for releasing the steam/air trapped in the
system. The piping should be properly examined after installation
to ensure that there is no leakage before insulating. There should
be a good quality non-return valve to ensure that hot & cold water
does not mix. While installing the hot water tank on the stand, proper
care should be taken to ensure that no stress develops on the welded
portion.
|
Q. 8 |
Are there any rules to ensure optimum
utilization of solar water heating system?
|
Ans 8 |
1. While selecting water-heating system
your needs and usage habits should be taken into account.
2. In conventional thermo-siphon system for proper flow of hot water
in the pipe equivalent amount of cold water should go into the hot
water tank. Hot water should be used keeping this in mind.
3. The glass on the panel should be kept clean.
4. Overhead cold water tank should always have water.
|
Q. 9 |
What is the basic difference between
solar thermal energy and solar electric energy? Whether it is possible
to produce electricity from the Solar Water Heating System?
|
Ans 9 |
Solar Thermal Energy is used for heating
by absorbing the heat from Sunlight. Converting Sunlight into electricity
produces solar electricity. Solar heating system cannot be used to
produce electricity at present.
|
Q. 10 |
What is the expected life of a solar
water heating system? What does it depend upon?
|
Ans 10 |
The life of solar water heating system
depends on the absorber, the construction of the collector, quality
of hot water tank & insulation etc. As mentioned above, a M. S.
tank may get rusted & start leaking
after 4-5 years, thereby resulting in lot of headache & expenditure
for replacement. An ideal solar water heating system should have high
quality panel, stainless steel (SS 304) tank, good quality pipes of
standard make & proper insulation. These things along with use
of soft water ensure a long life of system. Absorbers manufactured
with the existing technology
go through the coating processes at 28 degree Celsius temperature.
If the cold-water tank remains empty during the day (which possibility
cannot be avoided completely), temperature of approximately 180 degree
Celsius is created in the collector This causes the coating at the
absorber to weaken. This results in the reduction of effective life
of solar water heating system.
In Aksons’ PVDSunselect (TM) coating process, we heat the absorber
material to 300 degree Celcius while applying the solar selective
coating on it. Thus our absorber retains its efficiency and the coating
even after going through the temperature of 180 degree Celcius for
hundreds of hours. We believe that the solar water system manufactured
according to our technical benchmark and having our absorber will
have a life span of more than 25-years.
|
Q. 11 |
What is the maintenance cost of a solar
water heating system?
|
Ans 11 |
A technically sound system installed
by skilled technicians coupled with usage of water having salt contents
of less then 100ppm will require minimum maintenance. In this situation
the only maintenance work, which can easily be done by any common
man, is removing the dust on the glass of panel. If there are sediments
/ impurities in the water, remove the nut-bolts of flange of header
below the panel to let the water and impurities go out. If the water
contains dissolved salts more than 100ppm then you will have to use
water softener or you have to cleanse the system with water mixed
with acid after certain period. After 7-8 years the rubber parts of
the collector are advised to be replaced. Please ensure that the silicon
sealant is reapplied every 4-5 years to avoid leakage of water in
the collector. Electrical components of a forced circulation system
may need repairs replacement. Therefore before buying a solar water
heating system you have to find
whether the seller offers such service. Apart from this no other maintenance
is required. For forced circulation systems, electrical maintenance
may be required.
|
Q. 12 |
How is the capacity of a Solar Water
Heating System decided?
|
Ans 12 |
Generally cold water at 20 degree is
converted to hot water at 60deg. For this, assuming average availability
of the sunlight for 5.5hrs/ day the capacity of system is decided.
For deciding the required capacity of Solar Water Heating System,
habits of usage of hot water, number of persons in the household etc.
need to be taken into account.
|
Q. 13 |
What is certified “ISI”marked
Solar Water Heating System?
|
Ans 13 |
To protect the interest of consumer and
ensure proper return of their money the Bureau of Indian Standards
(BIS) benchmarks certain standards for every item. Based on these
quality standards a License to manufacture is issued& the collector
confirming to BIS 12933 - carries ISI mark.
|
Q. 14 |
What is the secret behind the Solar System
available for very low price? What are the deficiencies in it?
|
Ans 14 |
Very attractive low price, misleading
advertisements and verbal assurance by the seller lands one with low
quality system. There are systems available in the market at very
low prices. In these the material used is unproven, very low quality
without any scientific/technical base. These systems supplied at 50%
of price have only 50% efficiency and 20-25% life span as compared
to a good Metallic Solar Water Heater System. Thus the value for money
is only 12.5%. In case of systems using low quality material and sellers
who just assemble & sell, once the money is received the guarantee
is over.
Some of them are not knowledgeable and some are down right cheats,
so choose carefully.
|
Q. 15 |
Is there any subsidy for Solar Water
Heating System? What are the details?
|
Ans 15 |
as per the present Government policies
for Solar Water Heating System loan at subsidized interest rate is
given.
Instead of cash subsidies for upto 5000 liters/day capacity system
for domestic use a loan upto 75%of price is given at 5%per annum interest
rate. The installment per month comes to Rs.19.20 per thousand per
month. But for this there are some preconditions.
|
Q. 16 |
How to decide the right price of Solar
Water System?
|
Ans 16 |
The selection of system should be done
based on the proper technical specifications. The system adhering
to these specifications with most competitive price should be chosen.
|
Q. 17 |
How to ensure safety in the Solar Water
Heating System?
|
Ans 17 |
The cold water tank should be full otherwise
the steam generated can cause accident. The water coming from pipe
is hot and can cause burn so you should not take both directly under
the pipe/ shower without a good quality mixer.
|
Q. 18 |
What is the maintenance for the system?
|
Ans 18 |
As explained above, a solar system selected
on the basis of the technical specification needs very little maintenance.
But if the water is hard, acid cleaning is required periodically.
You should find out whether the dealer has the required knowledge
& material for this. Similarly parts made of rubber get damaged
& need to be replaced. This should be kept in mind, while selecting
solar system. For large size systems, electrical maintenance may also
be required.
|
Q. 19 |
What is the warranty of Solar Water Heating
System? What is its period?
|
Ans 19 |
The manufacturer /dealer takes responsibility
for the material used in the system & its workmanship for a period
called as warranty period. The contents / language of guarantee clause
needs to be examined carefully before buying solar system. Normally
it should be purchased from manufacturer, manufacturing the entire
system or their official dealer.
The Guarantee period is generally 1 to 5 years. This should be taken
into consideration. Similarly if defect is detected, how it will be
rectified & in what time frame should also be examined.
|
Q. 20 |
Are there any special exemptions in Income
Tax for Solar Water System consumer?
|
Ans 20 |
As per the income tax rule if any non
conventional energy is used, in case of equipments for usage pertinent
to business, 80% depreciation is granted in the 1st year of purchase.
This is available for solar system also.
|
Q. 21 |
Can loan be availed for an SWH System?
|
Ans 21 |
A soft loan @ 5% reducing interest can
be availed from the enlisted Banks. There are some formalities, which
every solar water heater manufacturer is aware of and it can be processed
with his help. The loan is of a specified amount according to the
capacity of the System to be installed.
|
Q. 22 |
What is the pay back period for investment
in Solar Water Heating System? What is the total saving over its effective
life span?
|
Ans 22 |
To answer this question certain assumptions
have to be made such as
1. Optimum utilization of system.
2. Utility for 300 days/year.
3. Increase of average 7% per annum in electricity charges.
4. 20 years life expected of the system.
Based on these assumptions the investment is recovered in 36 month
(including depreciation) in domestic system and in less than 24 months
in industrial/commercial (hostel etc.) system. The investment is repaid
at least 25 times over the life span of the system.
|
Q. 23 |
How much truth is there in the argument
that Solar Water Heating System results in increased water consumption?
|
Ans 23 |
There is no reason for increase in water
consumption. On the contrary the use of hot water for cleaning (cloths/utensil
cleaning etc.) minimizes the water usage. Solar Water System increases
the storage of water. Thus initially more water is required for storage
is increased but eventually the water consumption is reduced
|
Q. 24 |
What about the monsoon period in coastal
area like Mumbai?
|
Ans 24 |
Solar water heating systems with inferior
absorbers may not be giving satisfactory performance during the monsoons*.However
systems with Akson’s coated absorbers PVD Sunselect(TM) , Aksons’
patented high efficiency concentrator plate collector “QUASAR”
is most ideal for Mumbai & coastal areas will certainly give better
performance
during inclement weather conditions.
|
Q. 25 |
It is easy to fit a system on an individual
house, what about apartments/flats?
|
Ans 25 |
There are some practical difficulties
for installation of a system for a flat, but these can be overcome:
a) The flat owner has to install a system on the common terrace of
the building. He has to fit his own private pipeline from the heater
to the flat. If the distance is too much there are heat/temperature
losses. An NOC has to be procured from the Society. It all depends
on your society’s office bearers and your relations with them.
b) There can be a solution by explaining and enhancing the knowledge
of solar technology and its advantages to the people in general and
the office-bearer in particular. It’s financial benefits, environmental-friendliness,
social and economic advantages etc.
c) One could also bring to the people’s notice that a common
and bigger system would be more beneficial to all the members of the
building, ‘cause it brings down costs due to common piping,
distribution installation and insulation.
d) Individual, common or shared systems can be tailor-made and given
by us in different types as per requirements and financial availabilities.
e) Akson’s patented “DELTA” system offers the 100%
troublefree solution to society system.
|
Q. 26 |
What are the advantages of having a common
system and the disadvantages?
|
Ans 26 |
The primary advantages are in cost of
the system to each individual. The second is use of the common terrace
in a proper manner.The utilization of water with economy. Work would
be done only once for the entire building instead of in parts by individuals,
causing less nuisance and disturbance or damage. The disadvantage
is that the usage of hot water could be uncontrolled. There could
be objection of individuals on quantities used by others in case of
a common system. The other disadvantage is that one cannot have a
hot water system of whatever capacity one wants to one’s liking
and one’s use/requirement. You also don’t own your own
system. But then for this there are solutions with us. Like our patented
“DELTA” system. The advantage of flexibility lies with
the society members i.e. When flats of other members are empty or
unutilized the excess water can be utilized by members who are having
guests at their house so thereby nullifying the effect of shortage.
A common system also helps in maintenance and eases out complexities.
With proper planning and guidance a soft loan can also be availed
at 5% reducing interest. Bigger systems i.e. more then 1000lpd (liters
per day) will also be qualified for CER (Certified Emission Reduction)
credits from Developed nations. They have attractive rates of compensation.
|
Q. 27 |
What are the economics of individual
and collective solar water heating system?
|
Ans 27 |
If a common system is made, an individual
can save cost on account of piping, installation charges etc.
|
Q. 28 |
How much space is required for a common
solar water heating system? Can the terrace be kept free for use and
how?
|
Ans 28 |
Approximately 35 to 40 sq. ft. is required
for a 125 LPD. And a convenational 1000LPD system would take 350 to
400 sq.ft. These are the basic space requirements unless any specific
obstacles are encountered. The terrace is an important and pricey
possession of a building in a city .It is possible to install a solar
water heating system on it without using the terrace space. Unnecessary
piping, use of space and expenditure can be avoided by this. Most
of the users can take advantage as no NOC would be required. A superstructure
would make the space below convenient to use. Akson’s “DELTA”
system requires minimum space.
|
Q. 29 |
Can a Soft Loan be made available for
a common SWHS? How can this be availed?
|
Ans 29 |
A soft loan for a SWHS upto 5000 LPD
can be used for residential purpose. A soft loan @ 5% P. A. on reducing
balance can be availed from nationalised banks specified by the Ministry
of Non-Conventional Energy Sources. While taking this loan care has
to be taken that the advantage of CER trading should not be lost.
For further information you can contact M/s
|
Q. 30 |
How can we divide the expenses amongst
its members in case of a common SWHS for the society? How can we make
it equal and economic?
|
Ans 30 |
In order to avoid any discrepancies or
debate the number of people staying as well as visitors is taken into
consideration while calculating the size of the system. The society
maintenance should be taken as the base for cost contribution, which
we feel should be acceptable.In case of a conventional common system.
Akson’s “DELTA” System offers a perfect solution
for all the issues related with solar water heating system for a multistoried
residential building.
|
Q. 31 |
How can we guarantee the proper distribution
of hot water? How will we get hot water during the monsoons?
|
Ans 31 |
In case of a common system, if water
is given between a fixed time of 5 am to 10 am one could guarantee
hot water to all members. Since water for bathing is consumed during
these hours. Thus a small size system will suffice thereby making
it economical. If hot water is required throughout the day a Dual
tank system could be installed. This attracts extra expenditure. Akson’s
“DELTA” system gives freeedom to the individual flat owner
for use at his convenience. If water is drawn throughout the day in
a regular SWHS availability of hot water next day morning is hampered
severely as there is no time given for the system to heat fully during
the day when the sun is available. In the monsoon when there is shortage
of sunlight the connection of SWHS hot water which has already been
attached to the present geysers can be treated as a regular connection
and the geysers could be operated as usual.
|
Q. 32 |
Taking into consideration the limited
space on the terrace how one can facilitate a better SWHS option?
|
Ans 32 |
Akson’s “DELTA” system
using “QUASAR CPCS” results in highest capacity output
per m2 of terrace space.
|
Q. 33 |
What are the precautions required to
be taken for fitting a common SWHS system? How do we guarantee the
satisfactory
use and a long life?
|
Ans 33 |
1. The system should be carefully used
and operated by a single authority.
2. The toughened glass of the panels should be regularly cleaned
3. The superstructure on which the system is installed should be regularly
painted and protected against corrosion.
4. The SWHS should be insured.
5. Co-operation amongst members who use the system gives best results.
|
Q. 34 |
Apart form solar water heating system
how can solar energy be useful in our routine/ day-to-day life?
|
Ans 34 |
Solar water heater is one of the most
useful application of solar energy. Apart form this we can use solar
energy in the following form. “Missionaries of solar”
Akson’s Solar Equipments is a company founded by a highly experienced
visionary technocrat, based on fundamental Research & Development.
Akson’s is the first and the only company in India, manufacturing
solar selectively coated absorber surface (PVD Sunselect (TM), using
its own patented physical Vapor Deposition process. This process is
now used in all advanced nations, whereas all other absorber manufacturers
in India still use age old Electroplating process. To know more, please
contact Akson’s
Akson’s solar has also developed highly efficient “solar
oven” & parabolic cookers against the slow conventional
box cooker.
The solar collector is the heart of solar water heating system. Akson’s
Solar Lanterns Alternative for
continuous non-availability of electricity
Solar Street Lights Guaranteed
and safe light for Societies,
industries, Godowns etc.
Solar Home Lighting
System - Non dependence on electricity.
Solar Drier.
For Drying.
Solar Oven.
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| Q. 35 |
|
| Ans 35 |
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