Solar Water Heater

Pre Heated Pressure

• Inner tank material: SUS 316 Thickness (mm): 0.5
• Insulation: Polyurethane Thickness (mm): 50
• Frame angle (Degree): 30 degrees
• Vent connection (inch):1/2
• Electric heater connection (inch):1

The Working Principle:

• The solar collector consists of open vacuum tubes which absorb the solar energy from the sun rays, converting it into heat energy. When in contact with the cold water the energy produced heats up the water inside the vacuum tubes.
• As the water inside the tubes heats up, its density decreases and the hot water rises into the hot water storage tank. Due to its greater density, the cold water in the tank will flow down into the tube.
• The whole process is repeated and the hot water will circulate continuously until its temperature inside the hot water tank reaches that of the water inside the vacuum tube.
• This natural phenomenon is known as thermosiphon process
• Copper coil is installed inside the tank as the heat exchanger. When cold water flows into the heat exchanger, it absorbs heat from the hot water in the tank via the copper coil. Cold water under pressure enters the heat exchanger through the cold-water inlet and hot water comes out through the hot-water outlet.
• The unit is filled with cold water through an assistant tank to top up water loss through evaporation.

Split Compact

• Inner tank material: SUS 316 Thickness (mm): 1.2
• Insulation: Polyurethane Thickness (mm): 40
• Frame angle (Degree): 20 degrees
• Electric heater connection (inch):1
• Main flow: Red Copper

The Working Principle:

• A heat pipe is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer of heat between two solid interfaces. At the hot interface of the heat pipe a working fluid, sealed inside at depressurized condition, in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from the sun. Specially designed copper pipes are inserted into the vacuum tube.
• The heat pipes have a tiny amount of working fluid. When heated, the fluid inside the heat pipes vaporizes at low temperature (about 30°C), the vapour rises to the condenser and heat energy is conducted to the water inside the collector base.
• When vapour is cooled down, it condensates and falls to the bottom of the heat pipes by gravity. By continuously circulating in this way, energy from the sun is transferred to the fluid and heats the water inside the collector base until the cycle is completed.
• The collector set/manifold complete with the Heat pipes and Vacuum tubes is connected to the Compact Hot Water Tank to transfer and retain the heat energy through the water in the storage tank.
• Absence of water in the vacuum tubes, will allow the system to operate even if one tube is damaged.
• Ease of maintenance – In the Split Compact – The Heat pipes are connected through a Manifold instead of directly screwed in the water tank. The heat pipes from the Manifold can be easily removed for cleaning and removal of scales.

Split Unit

• Inner tank material: SUS316 Thickness(mm): 1.2
• Insulation: polyurethane Thickness(mm): 45
• Manifold connections (inch): 3/4 or 1
• Frame angle (Degree): 30 degrees
• Test pressure (Bar): 10
• Operating fluid pressure (Bar): 4
• Max. service temperature (degree): 95
• Max. stagnation temperature (degree): 250.3
• Distance from tube to tube (mm): 78
• Min. collector angle (degree): 15
• Max. Collector angle (degree): 75
• Max. distance advised between the collector and the hot water tank: 50 m

The Working Principle:

• A split system consists of a solar collector and a hot water storage tank
• The solar collector (manifold) is separated from the hot water tank. The manifold is placed on the roof and the hot water tank may be installed at ground level.
• The collector consists of a manifold and heat pipes
• A heat pipe is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer of heat between two solid interfaces. At the hot interface of the heat pipe a working fluid, sealed inside at depressurized condition, in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from the sun. Specially designed copper pipes are inserted into the vacuum tube.
• The heat pipes have a tiny amount of working fluid. When heated, the fluid inside the heat pipes vaporizes at low temperature (about 30°C), the vapour rises to the condenser and heat energy is conducted to the water inside the tank.
• When vapour is cooled down, it condensates and falls to the bottom of the heat pipes by gravity.
• By continuously circulating in this way, energy from the sun is transferred to the fluid and heats the water inside the manifold until the cycle is completed
• When the difference in temperature between the manifold and the hot water storage tank reaches the set value, the controller will start the circulation pump automatically.
• The pump then circulates the water through the circulation pipe into the manifold and back to the hot water storage tank.
• When the temperature of the water inside the hot water storage tank reaches that of the manifold, the circulating pump will then automatically switch off.
• When the temperature of the water tank does not reach the Tmax, the auxiliary heating device (electric booster) will switch on automatically.

• What is a non-pressure solar water heater?

A non-pressure solar water heater is classified as a “low” pressure when the water coming from the solar unit is gravity fed to your house. This means that whatever pressure you feed into the system it will still come out from the outlet and down to your house by gravity.

• When do I choose a Non pressure solar water heater?

When the cold water to your shower(s) is gravity fed from a tank on the roof or supplied by the CWA without usage of pump.

• What is a high pressure solar water heater?

A high pressure solar water heater gets water to your shower at a pressure up to 3.5 bar. It ensures a proper mixing of hot and cold water at the shower level.

• When do I choose a High pressure solar water heater?

If the cold water supply to the shower mixer comes under pressure, it is advisable to be equipped with a pressure type Solar Unit. The Pre Heated system is for coastal region.

• Why do I choose a Split Compact pressure solar water heater?

If the cold water supply to the shower mixer comes under pressure, it is advisable to be equipped with a pressure type Solar Unit. The Split compact is suitable for all region.

• What is a split solar water heater?

In the case of a split system, the hot water storage tank and collectors are installed separately from one another. The tank may be installed at ground level, while the collector(s) is mounted on the roof. The split system is equipped with a recirculating pump which circulates the water through the roof-mounted collector and back into the hot water tank.

• When do you recommend a split unit?

This really comes down to your personal preference and the design of your house. If aesthetics is a major criterion, it is the recommended to install a split unit with the collector on the roof and the storage tank at ground level.

• Why is a split unit more expensive?

A split unit requires additional feature such as the recirculation pump, the pump controller, the heat exchanger and associated valves and plumbing devices.

• How do I calculate the size of my solar water heater?

Family of 2 -3 persons: 150L

Family of 4 persons: 200L

Family of 6 persons: 300L

• What is the average lifetime of a solar water heater?

Your solar water heater will last 20 to 25 years

• The Solar water heater is made of what materials?
  • The inner and outer tank of the system is made of Inox 316
  • The frame is made of aluminium alloy
  • The tube is made of glass

• What warranty is offered on the Solar Water Heater?
  • 8 years on the water tank
  • 15 years on the tubes and frame
  • 1 year on the assistant tank

No warranty if the system is damaged due to cyclonic conditions

• Can the SWH be installed on an inclined roof?

Yes. In which case, a survey, free of charge must be done by a Duraco expert. However, an additional amount might be charged to the client depending on the modification to the metal support.

• What kind of maintenance is required for a Duraco Solar Water Heater?

The system requires very little maintenance. The tubes need to be cleaned from time to time, especially in the regions where there is lots of dust.

• Why buy a Duraco Solar Water Heater?
  • Made of materials which are rust proof – INOX 316 and Aluminium alloy – more appropriate for Mauritian Climatic conditions
  • Reliable supplier for more than 25 years
  • Registered with the DBM as an official supplier since 1995
  • Dedicated team of technician and installation
  • Availability of spare parts

• What is included in the price of the Solar Water Heater?

The price includes, delivery, flat roof fixation and VAT; but excludes plumbing and electrical works.

• Is there any credit facility for the purchase of a Duraco Solar Water Heater?

Yes, credit facilities are available through CIM finance

• Can I buy a system from you and then install it myself?

No. A self-installed system will not be covered by our warranty.

• What shall I do in case a tube breaks? Can I replace the broken tube myself?

The broken tube will have to be replaced by our technical team. In case of water leaking out of the system from the broken tube, shut the inlet and outlet valves.

• What happens on cloudy/rainy day? Do I still get hot water?

Our Solar Water heaters works with direct sun rays. On cloudy/rainy days you may lack hot water. However, our unit is equipped with an inbuilt electric booster which can be switched on when water is not sufficiently hot.

• If I shower in the evening, will I have hot water the next day?

Hot water produced by the solar radiation during the day is stored in an insulated storage tank. As long as the hot water has not been completely used up, the insulated tank will keep the water hot without significant drop in temperature for up to 24 hrs. Thus water heated during the previous day should be available for use at night and next morning.

• Will my system be damaged if I go away on holiday?

Nothing will happen to your solar unit as long as it is filled with water. It is mandatory for the Solar Water Heater to be filled with water.

• Are Solar water heater equipped with tubes collector more efficient than flat plate collector?

Due to the cylindrical shape of the tubes, the collector is able to passively track the sun throughout the day, whereas the flat plate collector only provides peak energy output at midday when the sun is perpendicular to the collector’s surface. Moreover, evacuated tubes are strong and long lasting. Furthermore, should one tube get broken, it is inexpensive and easy to replace. If a flat plate collector panel is damaged the whole panel must be replaced.

• Can I heat my swimming pool using your solar water heater?

No, our solar water heaters are only for domestic purposes

Warranty

The warranty is applicable to your DURACO solar hot water system (hereafter called the solar
system) and is as follows:

• Tubes and Heat Pipes: 180 months from the date of installation – Free replacement of failed tubes and heat pipes (Transport and Labour will be charged to owner)
• Manifold and frame: 180 months from date of installation – Free replacement of defective manifold and frame (Transport and Labour will be charged to owner)
• Solar Water Tank: 96 months from date of installation – (Transport and Labour will be charged to owner)
• Electric booster: 36 months from date of installation – (Transport and Labour will be charged to owner)
• Assistant tank & Float Valve: 12 months from date of installation (Transport & Labour will be charged to owner)

Warranty Conditions

The company’s obligation under this warranty is limited to repair or replacement of any part, or parts, of the solar system, at the option of the company

This warranty does not cover misuse, accident or failure from faulty installation, harsh or adverse water conditions or from attempts to repair the system by other than DURACO accredited technician or service agent.

The warranty only applies to the solar system and does not cover any plumbing or electrical parts such as pressure and temperature relief valves, air valve, float valve, stop cocks, non return valve, electrical switches, pumps, fuses and others.

Warranty Exclusions

1. Where the non-pressure solar system has been connected directly to a pressure supply (such as the water authority main pressure line, pressure pump etc..) and not to an open circuit header tank as is the correct installation procedure.
2. Accidental damage, acts of God (cyclonic weather), failure due to misuse incorrect installation, attempts to repair the system by other than DURACO accredited technician or service agent
3. Where it is found that the system does not suffer any defect, where there is no flow of hot water due to a faulty plumbing installation and not of the system or components, where there is a failure of water supplies
4. Subject to any statutory provisions to contrary claims for damage to furniture, carpets, walls, foundation, or any other consequential loss either directly or indirectly due to leakage from the system
5. Where the solar system has been installed and / or operated without the solar system being filled with water
6. Where the damage has been caused by an inflow of cold water into the system through the hot water pipe
7. Where the unit has been moved without the company’s prior approval
8. No warranty on the vacuum tubes (except manufacturing defect)

VERY IMPORTANT – When using electric booster

For safety precaution, make sure that electric booster is switched off before using hot water

All water connections from main supply to the cold-water inlet and from the hot water outlet to the hot water distribution lines MUST BE MADE WITHIN ONE WEEK OF INSTALLATION DATE