Soler Water Heating

SOLER WATER HEATING SYSTEM

Solar Water Heating

Overview Potential of Solar

Water Heaters in India Understanding Solar

Water Heaters Solar Water Heater

Classification & Types Guidelines solar water

heating Advantages of Solar

Water Heating System

Solar Water Heaters

Preheat incoming water using free energy

Can provide up to 75% of annual domestic hot water

Require back-up water heater

Water Basics

Water expands when it freezes

Hard water can be hard on your system

Definition

Solar water heating or solar hot water is water heated by the use of solar energy. Solar heating systems are generally composed of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage. The system may use electricity for pumping the fluid, and have a reservoir or tank for heat storage and subsequent use. The systems may be used to heat water for a wide variety of uses, including home, business and industrial uses. Heating swimming pools, underfloor heating or energy input for space heating or cooling are more specific examples

Potential of Solar Water Heaters

Solar thermal technologies hold significant promise for India with high solar insulation of 4 – 6.5 kWh/ sq.m /day for an average of 280 sunny days. Solar water heating system is a commercially viable and technologically mature product which has existed in the country for many years. Yet, against a technical potential of 45 million sq. km. of collector area only a little over 2.5 million sq. km of collector area has been installed. This works out to a little more than 2 sq.m./1000 people as against countries like Israel and Cyprus, which have over 500 sq.m./1000 people.

Potential of Solar Water Heaters

In order to transform the solar water heating market in India, the Ministry of New and Renewable Energy (MNRE) has joined hands with UNDP/UNEP/GEF Global Solar Water Heating Market Transformation Strengthening Initiative. Under this project, India aims to achieve 10 million sq meter additional collector area by 2012. In absence of any intervention, the market was projected to add 3 million sq meters during this period. International Copper Promotion Council (India) is partner to this project in India.

Understanding Solar Water Heaters

If we can control the exchange of heat between the dark material surface and the material that is required to be heated up by way of conduction or convection, that would be a desirable heat exchange. The devices, used for solar heating, try to increase this desirable heat exchange and reduce the undesirable heat exchange to atmosphere or other materials in contact. The device that is used for the controlled heat exchange and for converting the solar energy into useful heat is called ‘solar collector’.

Understanding Solar Water Heaters

The solar radiation happens in two forms.

•Direct solar radiation is the radiation happens from the sun directly.

•The diffused solar radiation, which is scattered by the atmosphere or is reflected from the surrounding area in a random form.

Solar Water Heater Classification

As key components in building solar water heaters, solar heat collectors accept solar irradiation and deliver energy to water in the solar heat application system. Considering solar collector types, solar water heaters are classified into plate solar heaters and evacuated Tube.

Types of CollectorsFlat Plate

Proven Technology Durable Temperature operating

range perfect for SDHW & space heating

Collectors shed snow Repairable Competitively priced

Types of CollectorsEvacuated Tube

Moderately high temperature collector

Collector design varies by manufacturer

Some tubes have moving parts

Glass tubes are fragile Do not shed snow and frost

as well as flat plate collectors

Types of Solar water Heating

Direct and indirect systems

Passive and active systems

Passive direct systems

Active indirect systems: drainback and

antifreeze

A rough comparison of solar hot water

systems

Types of Solar water

HeatingDirect & Indirect System

Direct or open loop systems circulate potable water through the collectors. •They are cheaper than but can have drawbacks:•They offer little or no overheat protection unless they have a heat export pump.•They offer little or no freeze protection, unless the collectors are freeze-tolerant.•Collectors accumulate scale in hard water areas, unless an ion-exchange softener is used.

Passive CHS system with tank above collector.


HeatingDirect & Indirect System

Indirect or closed loop systems use a heat exchanger that separates the potable water from the fluid, known as the "heat-transfer fluid" (HTF), that circulates through the collector.

Indirect system with heat exchanger in tank


HeatingPassive & Active System

Passive systems rely on heat-driven convection or heat pipes to circulate water or heating fluid in the system. Passive solar water heating systems cost less and have extremely low or no maintenance, but the efficiency of a passive system is significantly lower than that of an active system, and overheating and freezing are major concerns.


HeatingPassive & Active System

Active system with pump and controller driven by a photovoltaic panel

Active systems use one or more pumps to circulate water and/or heating fluid in the system.•Though slightly more expensive, active systems offer several advantages:•The storage tank can be situated lower than the collectors, allowing increased freedom in system design and allowing pre-existing storage tanks to be used.•The storage tank can always be hidden from view.•The storage tank can be placed in conditioned or semi-conditioned space, reducing heat loss.•Drain back tanks can be used.•Superior efficiency.•Increased control over the system.


HeatingPassive Direct SystemAn integrated collector storage (ICS

or Batch Heater) system uses a tank that acts as both storage and solar collector. Batch heaters are basically thin rectilinear tanks with a glass side facing the position of the sun at noon.

An integrated collector storage (ICS) system


HeatingActive indirect systems: drain back and antifreeze Drain back

Advantages can withstand moderate freezing conditions not affected by hard water uses distilled water as the heat transfer fluid – most

efficient and no fluid degradation virtually maintenance free can be part of a combination system versatile installation options using flat plate collectors

Disadvantages can be damaged under severe freezing or snowy

conditions require careful pipe installation require a high-head pump and a vertical distance

between the collectors and the reservoir of less than 25 feet

Drainback system with drainback reservoir. In these schematics the controller and pump are driven by mains electricity


HeatingActive indirect systems: drain back and antifreeze


HeatingActive indirect systems: drain back and antifreeze Antifreeze

Advantages not affected by freezing

conditions not susceptible to mineral

buildup from hard water no limit to the distance between

collectors and storage can be PV powered has most installation options proven technology virtually maintenance free most systems have only one or

two moving parts can be part of a combination

space heating/domestic water heating system

Disadvantages cost slightly more than other

systems slight loss of efficiency due to

heat transfer fluid fluid degradation under

extended stagnation


HeatingActive indirect systems: drain back and antifreeze

Guidelines of Solar Water heatersSystem design requirements

The type, complexity, and size of a solar water heating system is

mostly determined by:

•The temperature and amount of the water required from the

system.

•Changes in ambient temperature and solar radiation between

summer and winter.

•The changes in ambient temperature during the day-night cycle.

•The possibility of the potable water or collector fluid overheating.

•The possibility of the potable water or collector fluid freezing.

Solar lighting and water heater requirements

Sl.No.

Type of use 100 liters per day shall beprovided for every unit

1 Restaurants serving food and drinks with seating / serving area of more than 100 sq.m and above

40 sq. m. of seating or serving area

2 Lodging establishments and Tourist Homes 3 rooms

3 3 Hostel and guest houses 6 beds / persons capacity

4 Industrial canteens 50 workers

5 Nursing homes and hospitals 4 beds

6 Kalyana Mandira, Community Hall and Conventional hall (with dining hall and kitchen)

30 sq. m of floor area

7 Recreational clubs 100 sq. m of floor area

8 Residential buildings

a)Single dwelling unit measuring 200 sq.m of floor area or site area of more than 400sq.m whichever is more

9 b) Solar photovoltaic lighting systems shall be installed in multi unit residentialbuildings (with more than five units for lighting the set back areas and drive ways)

Advantages of Solar water HeatingEnvironmental Benefits

A typical solar water heating system will offset between 3/4 ton and 1 ton of CO2 per year - the equivalent of driving over 1,300 miles (@22mpg)

Solar water heaters are one piece of the puzzle in reducing greenhouse gas emissions

Natural gas, just like oil, is a limited resource that is being depleated

Advantages of Solar water HeatingEconomical Benefits

Life Cycle Costing Overall cost of

comparable systems Solar water heaters have

no operating costs Add initial cost plus

operating expenses Compare final cost after a

period of time

Thank You！

Raghav Sangwan 9110021

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Soler Water Heating