Solar Guide | Read Before you Buy

When selecting a solar water heater, there are several factors you should consider to ensure that you choose the right system for your needs. Here are some key considerations:

  1. Size: The size of the solar water heater should be based on your household’s hot water needs. A larger family will require a larger system to provide sufficient hot water.  thumb rule 50 ltrs per elederly person.
  2. Efficiency: The efficiency of the solar water heater is an important consideration as it will affect the amount of hot water the system can produce and how much energy it will save. Look for a system with a high-efficiency rating.
  3. Climate: The climate in your area will affect the performance of the solar water heater. If you live in a colder climate, you may need a larger system to compensate for the reduced sunlight available in the winter months.
  4. Type of system: There are two main types of solar water heaters – passive and active. Passive systems are typically less expensive but are less efficient. Active systems use pumps to circulate the water and are more expensive but more efficient.
  5. Warranty and maintenance: It’s important to consider the warranty and maintenance requirements of the system before you buy it. Look for a system with a good warranty and make sure you understand what maintenance is required.
  6. Cost: The cost of the system is obviously an important consideration. Consider the initial cost as well as any ongoing maintenance costs and the potential energy savings.

By considering these factors, you can select a solar water heater that is best suited to your needs and can provide you with an affordable and efficient source of hot water. It’s always a good idea to consult with a professional installer who can help you choose the right system for your home and provide guidance on installation and maintenance.

What are the types of solar water heaters available?

 FPC Type and ETC Type Systems are available  


FPC Type:

FPC stands for “Flat Plate Collector,” which is a type of solar thermal collector used in solar water heating systems. A solar water heater is a device that uses the energy from the sun to heat water for domestic or commercial use.

In an FPC solar water heater, flat plates made of materials such as copper or aluminium are used to absorb the sun’s radiation and transfer the heat to water, which flows through tubes in the collector. The heated water is then stored in an insulated tank for later use.

FPC solar water heaters are typically more efficient than other types of solar collectors, and they can be used in a wide range of climates. They are commonly used in homes, hotels, hospitals, and other commercial and industrial settings. The use of solar water heaters can help reduce reliance on non-renewable energy sources and lower greenhouse gas emissions.

ETC Type:

ETC (Evacuated Tube Collector) solar water heater is a type of solar water heating system that is used to heat water using energy from the sun. It consists of a series of glass tubes that are sealed at both ends and coated with a special material that absorbs solar radiation.

The tubes are connected to a manifold that carries water, which is heated as it circulates through the tubes. The hot water is then stored in an insulated tank for later use.

ETC solar water heaters are highly efficient and can provide hot water even on cloudy days. They are also environmentally friendly, as they do not produce any greenhouse gas emissions. They are commonly used in residential, commercial, and industrial settings and can provide significant energy savings over traditional water heating methods.

Minimum Requirements to install a solar water heater

1) Shadow Free Terrace or open area, a Minimum of 4-5 hours of shadow-free sunlight is required for good performance.  We are not responsible for weather conditions.

2) The base of Over Head Tank Height should be at least 5 feet from the floor level (please see photo below)  Click the image for a larger photo.

ETC Type solar fixing

3) After Plumbing work is over, water is to be let in only after 10 pm or before 6 am for the first time.   This is because the tubes have to cool down before water is let in, or else tubes will break within seconds because there is no Guarantee for ETC Glass tubes and chargeable.  Hence keep this in mind and inform the plumber also.  Because each tube may cost around Rs.1,600 each to replace.  

4) The slope of the collector should always Face towards the south to get the maximum benefit of solar radiation.  If not, a solar water heater may not work.

5) Space Requirements for solar water are shown below.  Click to enlarge the image.

6) SS304 Grade steel tanks are not suitable for borewell water/water hardness above 400 TDS.  Hence buy ether CERAMIC coated tank for UPTO 1000 TDS, and GLASS LINE coated tank for UPTO 1300 TDS.  Test water hardness before you buy.

supreme solar 220 GL Specification

How many litres system to select?

50 Liters per person is an approximate thumb rule.  Remember that a solar water heater is installed just above the bathroom floor.

100 Liters Suitable for 2 to 3 persons per day
150 Liters Suitable for 3 to 4 persons per day
200 Liters Suitable for 4 to 5 persons per day
250 Liters Suitable for 5 to 6 persons per day
300 Liters Suitable for 6 to 8 persons per day
500 Liters Suitable for 10 to 14 people per day

In case there is more than one floor between the bathroom and the terrace, you may have to recalculate the size of the solar tank.  You can call me on 9632417722 I will help you with this.

For example for 2 elderly persons and a child you can buy a 100-litre solar water heater, that will be enough.

How the solar water heater works

The solar water heater absorbs sunlight by a solar collector passing this hot water to the solar tank. Conversely. The efficiency of the collectors is at its highest at midday, in summer, when the sky is cloudless, and facing south. However, the collectors also work well in other seasons, when the sky is cloudy, for a good part of the day, even if they face east or west. Likewise, the efficiency is best at a gradient of 35° to the horizon, but good results can be achieved with collectors fitted vertically to a façade. When there is insufficient sunlight, the water is preheated and a backup system takes over to bring the water to the required temperature. This system can, therefore, be used to produce hot water at a constant temperature throughout the year without emitting any CO2.

Do solar water heaters work on cloudy days?

Since solar energy systems require sunlight, the bulk of production will take place under sunny conditions only. The output is directly proportional to the amount of infrared sunlight available at any given moment. A system can generate 50-70% of its typical output under bright overcast conditions. When rain or excessive days of cloudy conditions exist, the use of auxiliary backup where conventional energy will be needed.

what are the advantages of a solar water heater?

Energy Cost is entirely free of cost. So, while you are using a solar water heater unit, you won’t need to worry about a hundred dollars of utility bills.

The most amazing thing regarding solar water heating systems is- you will be getting the energy to run your water heater as long as the sun shines and wondering, what will happen in sudden wet weather or rainy day? FYI, many solar units are capable of providing you energy even when the sun is not shining. So, you won’t have to worry about running short of hot water even on cloudy days.

Save Space requires less installation space compared to conventional gas or fuel-run water heaters. Still, solar water heaters are more frugal in terms of installation space. Moreover, in most cases, the PV or thermal panels are installed on the rooftop.


Does a  solar water heater help the environment?

yes, it Keeps the environment clean and pollution-free, which has become the demand of recent times. A solar water heating system is environment-friendly as it doesn’t burn any fossil fuel when heating water for you. So, you have the chance to contribute to the environment and take part in the go green revolution

Do solar water heater works in winter?

With good insulation, sunlight will be able to heat the water quite well in a solar water heater winter. The heating is caused by the radiation energy of the sun, which can come through the glass and heat enclosures, even if the outside
temperature is well below freezing – providing good insulation can ensure very small heat loss.  Hence hot water is available during winter too.

Does the solar water heater work at night?

No, but hot water generated during the daytime gets stored in the solar tank which is insulated.  A good PUFF insulated tank can keep hot water for more than 24 hours regardless of outside weather conditions.

Does a solar water heater save money?

you might be knowing that the government has been encouraging people to go for various renewable energy options. Besides, they are also offering lots of schemes in renewable energy sectors, as well. Apart from that, investing in
a solar water heating unit is- one time, and it doesn’t require many things else a few necessary fittings. Moreover, the price of solar equipment is decreasing with every living day, and many companies are offering more efficient solar equipment at less investment. So, summing up all these, you will surely save some bucks on installation costs compared to a conventional water heater unit.

can solar water heaters generate electricity?

No. it cannot generate electricity as these are thermal collectors.  only solar photovoltaic panels are used to generate electricity.

how much energy/electricity solar water heater save

A 150-litre capacity solar water heater system is suitable for 3-4 people and can save up to 1500 units of electricity in a year, depending on the hot water used. It can also save.

How long do solar hot water systems last?

approximately around 15-20 years depending upon various techniques used to protect the inner tank of the solar water heater system,   a glass-lined coated tank from supreme solar can last well over 25 years and in some parts of the world, it’s in operation for more than 20 years.

What size/capacity of solar hot water do I need?

As a rule of thumb, a relative water-efficient household is looking at a system size of 50 litres per person depending upon how many floors the hot water is coming to your bathroom.   If for example, you installed a solar water heater just above your bathroom terrace floor, then 100 ltrs is enough for 2 to 3 people.  If the solar water heater is above 2 floors then you need 150 ltrs.  Because the waste of water goes higher as the floor level increases.

what are the types of solar water heaters available

1. ETC evacuated tube collector type,

2. FPC Flat panel collector is the major two type.

And there are pressurized and non-pressurized systems available, choose the one depending on the water pressure you require. If you are unsure about this, please call us, and we will help you.

Evacuated Tube Collectors (ETC)

Evacuated Tube Collector is made of double-layer borosilicate glass tubes evacuated for providing insulation. The outer wall of the inner tube is coated with selective absorbing material. This helps the absorption of solar radiation and transfers the heat to the water which flows through the inner tube.

Flat Plate Collectors (FPC)

The solar radiation is absorbed by Flat Plate Collectors which consist of an insulated outer metallic box covered on the top with a glass sheet. Inside there are blackened metallic absorber (selectively coated) sheets with built-in channels or riser tubes to carry water. The absorber absorbs the solar radiation and transfers the heat to the flowing water

Professional Help:  Cost 500/- per site visit, Book by advance payment along with location map, name and address via WhatsApp with a screenshot of payment made.  

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