GB2047858A

GB2047858A - Improvements in or relating to solar hot water systems

Info

Publication number: GB2047858A
Application number: GB8004626A
Authority: GB
Original assignee: BRAEMER APPLIANCES Pty Ltd
Current assignee: BRAEMER APPLIANCES Pty Ltd
Priority date: 1979-02-13
Filing date: 1980-02-12
Publication date: 1980-12-03
Also published as: NZ192887A; AU5547480A; AU534148B2; GB2047858B

Abstract

A solar/gas hot water system comprising a pair of interconnected water tanks 2, 3 tank 2 being associated with a thermostatically controlled gas burner 5 for maintaining water therein above a predetermined temperature and including a hot water outlet 13 for supply of hot water for consumer use, the other tank 3 being supplied from a cold water source e.g. mains supply, the water in tank 3 being circulated to a solar heat collector during hours of sunlight for preheating said water prior to supply to the gas fired tank 2. <IMAGE>

Description

SPECIFICATION Improvements in or relating to solar hot water systems This invention relates to solar hot water systems.

Presently, solar hot water systems are known in which electric elements are immersed in the body of the storage tank at a point spaced above the bottom of the tank (say half depth) so that the element heats approximately half of the total volume. The bottom half of the tank is heated by a solar collector unit through which water is circulated during hours of sunlight. The pump can be operated by a time cycle or thermostatically so that it is energised only when the sun is shining. Thus ifthere is no sunlight on the solar collector the temperature of water above the element is boosted by electrical energy.

It is an object of the present invention to provide a solar hot water system boosed by has heating.

According to the present invention in one aspect, there is provided a solar/gas hot water system comprising an upper and lowertank interconnected by a pipe or pipes, the upper tank including, or being associated with, a thermostatically controlled gas burner for maintaining water therein hot and including a hot water outlet, and the other lower tank, in use, being supplied by a cold water source and being connected to a solar heat collector to which water is circulated.

In a further aspect of the invention there is provided a solar/gas hot water system comprising a pair of water tanks interconnected by a pipe or pipes, one of said tanks including or being associated with a thermostatically controlled gas burner for maintaining water therein above a predetermined temperature and including a hot water outlet for supply of hot water for consumer use, the other of said tanks adapted to be supplied from a cold water source when in use, the water in said other tank being adapted to be circulated to a solar heat collector for preheating said water priorto supply to said one tank.

Conveniently, the water is circulated to the solar collector by a pump energised during hours of sunshine. Thus, when the water is being solar heated, water drawn off the bottom tank into the top tank is preheated and gas firing of the top tank is or may be unnecessary. Optionally, the gas burner is associated with a conventional vertical flue or alternatively a balanced flue system suitable for outdoor use.

A preferred embodiment of the invention will now be described, by way of example only, with referpence to the accompanying drawings in which Figure 1 is a water heater with a conventional flue and Figure 2 is a similar system with a balanced flue system.

In the drawings, the system -- generally designated as 1 -- comprises a top tank 2 and a bottom tank 3 encased in a cylindrical, upright, insulated housing 4. Between the two tanks 2, 3 is a thermostatically controlled gas burner 5. The system 1 also includes a solar heat collector (not shown) of conventional construction in communication with the tank 3, and water can be circulated between the tank and collector with the aid of a small pump 6.

The bottom 7 of the top tank 2 accommodates a combination gas control 7a which incorporates a thermostat for the burner 5. A baffled flue 9 extends the height of the tank 2. Also within the tank 2 is a sacrificial anode 10 which provides added protection against corrosion of the tank. The top 11 of the tank is provided with a pressure and temperature relief valve 12, operable in the eventthatthe incoming water pressure is in excess of that for which the tank was designed; it also includes a hot water outlet 13.

An inter-connecting pipe 14 is coupled to the side 15 (and side 16 of tank 3) and affords a communication between both tanks. Adrain 16a is provided nearthe bottom 7 of the tank and enables sludge to be removed therefrom.

The bottom tank 3 on the other hand is furnished with a cold water inlet 17 and a solar collector inlet and outlet 18 and 19, respectively. A sacrificial anode, 20, is again provided. If desired the cold water inlet pipe may be combined by way of a tee junction (not shown) with the outlet pipe 18.

In operation of the system during for instance a sunny day, cold water from the bottom tank 3 is circulated by a pump (not shown) through pipes 18, 19 through a solar collector. As hot water is required it is drawn off the top tank through outlet 13. As water is drawn off water flows from the bottom tank 3 into the top tank 2 through pipe 14. Ifthe water received from the bottom tank is sufficiently hot the thermostat 8 does not come into play and no gas is utilised to heat the water in the top tank. In the event that there is no sun, or it is not sufficiently strong for the purposes at hand, the gas burner 5 provides the necessary boost of heat energy to maintain the water in the top tank hot.

The flue arrangement 30 in Figure 2 provides openings 31, 32 ducted to supply air to the gas burner 5 and take flue gases away. The openings are provided at the side or front of the cabinet near the top. Such an arrangement is not susceptible to disturbances by wind gusts and also rain cannot enter the burner chamber. Accordingly, the balanced flue system provides a semi sealed arrangement suitable for use where the installation is exposed to the elements.

1. A solar/gas hot water system comprising a pair of water tanks interconnected by a pipe or pipes, one of said tanks including or being associated with a thermostatically controlled gas burner for maintaining water therein above a predetermined temperature and including a hot water outlet for supply of hot water for consumer use, the other of said tanks adapted to be supplied from a cold water source when in use, the water in said other tank being adapted to be circulated to a solar heat collector for preheating said water prior to supply to said one tank.

2. A solar/gas hot water system comprising an

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to solar hot water systems This invention relates to solar hot water systems. Presently, solar hot water systems are known in which electric elements are immersed in the body of the storage tank at a point spaced above the bottom of the tank (say half depth) so that the element heats approximately half of the total volume. The bottom half of the tank is heated by a solar collector unit through which water is circulated during hours of sunlight. The pump can be operated by a time cycle or thermostatically so that it is energised only when the sun is shining. Thus ifthere is no sunlight on the solar collector the temperature of water above the element is boosted by electrical energy. It is an object of the present invention to provide a solar hot water system boosed by has heating. According to the present invention in one aspect, there is provided a solar/gas hot water system comprising an upper and lowertank interconnected by a pipe or pipes, the upper tank including, or being associated with, a thermostatically controlled gas burner for maintaining water therein hot and including a hot water outlet, and the other lower tank, in use, being supplied by a cold water source and being connected to a solar heat collector to which water is circulated. In a further aspect of the invention there is provided a solar/gas hot water system comprising a pair of water tanks interconnected by a pipe or pipes, one of said tanks including or being associated with a thermostatically controlled gas burner for maintaining water therein above a predetermined temperature and including a hot water outlet for supply of hot water for consumer use, the other of said tanks adapted to be supplied from a cold water source when in use, the water in said other tank being adapted to be circulated to a solar heat collector for preheating said water priorto supply to said one tank. Conveniently, the water is circulated to the solar collector by a pump energised during hours of sunshine. Thus, when the water is being solar heated, water drawn off the bottom tank into the top tank is preheated and gas firing of the top tank is or may be unnecessary. Optionally, the gas burner is associated with a conventional vertical flue or alternatively a balanced flue system suitable for outdoor use. A preferred embodiment of the invention will now be described, by way of example only, with referpence to the accompanying drawings in which Figure 1 is a water heater with a conventional flue and Figure 2 is a similar system with a balanced flue system. In the drawings, the system -- generally designated as 1 -- comprises a top tank 2 and a bottom tank 3 encased in a cylindrical, upright, insulated housing 4. Between the two tanks 2, 3 is a thermostatically controlled gas burner 5. The system 1 also includes a solar heat collector (not shown) of conventional construction in communication with the tank 3, and water can be circulated between the tank and collector with the aid of a small pump 6. The bottom 7 of the top tank 2 accommodates a combination gas control 7a which incorporates a thermostat for the burner 5. A baffled flue 9 extends the height of the tank 2. Also within the tank 2 is a sacrificial anode 10 which provides added protection against corrosion of the tank. The top 11 of the tank is provided with a pressure and temperature relief valve 12, operable in the eventthatthe incoming water pressure is in excess of that for which the tank was designed; it also includes a hot water outlet 13. An inter-connecting pipe 14 is coupled to the side 15 (and side 16 of tank 3) and affords a communication between both tanks. Adrain 16a is provided nearthe bottom 7 of the tank and enables sludge to be removed therefrom. The bottom tank 3 on the other hand is furnished with a cold water inlet 17 and a solar collector inlet and outlet 18 and 19, respectively. A sacrificial anode, 20, is again provided. If desired the cold water inlet pipe may be combined by way of a tee junction (not shown) with the outlet pipe 18. In operation of the system during for instance a sunny day, cold water from the bottom tank 3 is circulated by a pump (not shown) through pipes 18, 19 through a solar collector. As hot water is required it is drawn off the top tank through outlet 13. As water is drawn off water flows from the bottom tank 3 into the top tank 2 through pipe 14. Ifthe water received from the bottom tank is sufficiently hot the thermostat 8 does not come into play and no gas is utilised to heat the water in the top tank. In the event that there is no sun, or it is not sufficiently strong for the purposes at hand, the gas burner 5 provides the necessary boost of heat energy to maintain the water in the top tank hot. The flue arrangement 30 in Figure 2 provides openings 31, 32 ducted to supply air to the gas burner 5 and take flue gases away. The openings are provided at the side or front of the cabinet near the top. Such an arrangement is not susceptible to disturbances by wind gusts and also rain cannot enter the burner chamber. Accordingly, the balanced flue system provides a semi sealed arrangement suitable for use where the installation is exposed to the elements. CLAIMS

2. A solar/gas hot water system comprising an upper and a lower tank interconnected by a pipe or pipes, the upper tank including, or being associated with, a thermostatically controlled gas burner for maintaining water therein hot and including a hot water outlet, and the other lower tank, in use, being supplied by a cold water source and being connected to a solar heat collectorto which water is circulated.

3. A solar/gas hot water system as claimed in claim 1 or claim 2 wherein said water is adapted to be circulated by a pump energised during periods of sunshine.

4. A solar/gas hot water system substantially as herein described when having reference to the accompanying drawings.