Gas water heater with increased thermal efficiency and safety

Abstract

A gas water heater having increased thermal efficiency comprises a water tank having a sealed combustion chamber thereunder. An atmospheric burner is located in the combustion chamber. A flue pipe extends from the sealed combustion chamber and through the water tank for heat exchange of hot atmospheric gas therein with water in the water tank. A heat exchanger is in communication with the combustion gases exiting the water tank to extract residual heat from the combustion gas in the flue pipe for mixture with ambient air to produce pre-heated combustion air. An air convection or draft inducing device directs the hot combustion air from the heat exchanger through a sealed conduit to direct the pre-heated combustion air to the combustion chamber.

Description

TECHNICAL FIELD[0001]The present invention relates to a gas water heater having increased thermal efficiency and wherein pre-heated combustion air is drawn from above the water heater housing.BACKGROUND OF THE ART[0002]It is known from our pending application Ser. No. 12 / 886,910 filed Sep. 21, 2010 to provide heat exchangers with hot water heaters whereby to extract residual heat from the flue gases exiting the water heater to heat ambient air in the surrounding space and / or to feed the recovered heat into the ducting system of the building.[0003]It is also known in the prior art to integrate heat pumps with domestic hot water heaters wherein the hot gases are used in heat exchange with water circulated from the hot water heater to provide an added heat source to heat water and this usually results in complex devices integrated together in a single unit. A disadvantage of these integrated systems is that they are expensive to fabricate and require additional maintenance. Also, after...

AI Technical Summary

Benefits of technology

The present invention is related to a gas water heater with improved thermal efficiency. One embodiment is characterized by the fact that the combustion air is heated up before coming into contact with the flames in the combustion chamber. This improves the heat transfer process, resulting in increased efficiency of the heat exchanger. Another embodiment has a sealed chamber that prevents the detection of explosive gases near the heater, which could potentially cause an explosion. The invention also includes a feature that allows for the external installation of a gas detector to further minimize the risk of explosions.

Problems solved by technology

It is also known in the prior art to integrate heat pumps with domestic hot water heaters wherein the hot gases are used in heat exchange with water circulated from the hot water heater to provide an added heat source to heat water and this usually results in complex devices integrated together in a single unit.

A disadvantage of these integrated systems is that they are expensive to fabricate and require additional maintenance.

Accordingly, such hot water heaters are expensive to fabricate and maintain and the economical advantages of such systems are therefore not realizable due to added costs.

However, these combustion air conduits have been known to block due to debris such as lint entering the conduit or blocking a screen at the entrance.

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