Patent Application
20130247843
The present invention relates generally to water heaters, and more particularly, to systems and methods for venting water heaters.
Conventionally, water heaters are employed (e.g., in one or more buildings) to generate and maintain a readily-usable source of hot water for use (e.g., by the building's occupants). To generate the heat for heating the water, water heaters include a source of fuel, such as oil or natural gas, which is burned in a combustion chamber. This consumption of fuel generates exhaust gas, which must be vented from the water heater. There exists a need for improved systems and methods for venting exhaust gas from water heaters.
Aspects of the present invention are directed to systems and methods for venting a water heater.
In accordance with one aspect of the present invention, a vented water heating system is disclosed. The vented water heating system comprises a fuel-fired water heater, a blower, a draft hood, and a thermal switch. The water heater has a combustion gas exhaust outlet. The blower is positioned to advance combustion gas exhausted from the combustion gas exhaust outlet of the fuel-fired water heater. The blower has a blower inlet positioned to receive combustion gas and a blower outlet positioned to exhaust combustion gas. The draft hood defines a passageway positioned to receive combustion gas exhausted from the blower outlet. The draft hood at least partially defines a relief opening positioned to allow gas to enter into or exit from the passageway of the draft hood. The thermal switch is positioned to detect a blockage in the passageway of the draft hood and is coupled to deactivate the water heater when a blockage is indicated.
In accordance with another aspect of the present invention, a kit for venting a water heater is disclosed. The kit comprises a draft hood configured to be attached to the water heater on top of a blower outlet of the water heater. The draft hood is configured to receive the exhaust gas blown through the blower outlet.
In accordance with yet another aspect of the present invention, a method for venting a water heater is disclosed. The method comprises blowing exhaust gas outward through a blower outlet of the water heater, and receiving the exhaust gas blown through the outlet with a draft hood positioned on top of the blower outlet.
In accordance with still another aspect of the present invention, a method for configuring a vented water heating system to detect a blockage in a passageway of a draft hood is disclosed. The method comprises positioning a thermal switch downstream of a blower of the water heating system, the thermal switch positioned to detect a blockage in the passageway of the draft hood, and coupling the thermal switch to the water heating system such that the thermal switch is operable to shut down the water heating system when the thermal switch senses a temperature above a predetermined limit.
The invention is best understood from the following detailed description when read in connection with the accompanying drawings, with like elements having the same reference numerals. When a plurality of similar elements are present, a single reference numeral may be assigned to the plurality of similar elements with a small letter designation referring to specific elements. When referring to the elements collectively or to a non-specific one or more of the elements, the small letter designation may be dropped. This emphasizes that according to common practice, the various features of the drawings are not drawn to scale unless otherwise indicated. On the contrary, the dimensions of the various features may be expanded or reduced for clarity. Included in the drawings are the following figures:
Aspects of the present invention relate to the ventilation of powered, atmospherically-vented water heaters. As used herein, the term “powered” in relation to ventilation refers to water heaters having a powered device, such as one or more blowers or fans, positioned to propel exhaust gas away from the combustion chamber and out of the water heater. Further, as used herein, the term “atmospherically-vented” refers to water heaters that vent exhaust gas to the atmosphere via non-positive static pressure venting.
While the systems and methods disclosed herein are described with respect to conventional water heaters, it will be understood that the invention is not limited to devices for heating water (i.e. H2O). As used herein, the term “water heater” is intended to comprise any device adapted to generate and maintain a source of heated fluid.
Generally, the disclosed systems and methods utilize a draft hood positioned on top of the blower to improve the water heater's resistance to downdrafts. The draft hood enables the creation of negative pressure adjacent the blower outlet. The draft hood desirably includes a thermal switch coupled to the draft hood to monitor the flow of exhaust gas away from the water heater, and control operation of the water heater accordingly.
Referring now to the drawings,
Blower 120 propels exhaust gas away from the combustion chamber of water heater 10. Blower 120 includes a blower inlet 122 and a blower outlet 124. Blower 120 further includes an impeller 126 (e.g., a fan) for propelling the exhaust gas. Impeller 126 is powered by motor 128. Through operation of impeller 126, blower 120 is operable to draw exhaust gas inward from the combustion chamber through blower inlet 122, and blow the exhaust gas outward through blower outlet 124.
In an exemplary embodiment, blower 120 is positioned within a top portion of water heater 10. The size and positioning of blower inlet 122 and blower outlet 124, as well as the selection of a suitable impeller 126, may be selected based on the quantity of exhaust gas to be vented by blower 120. Suitable blowers 120 will be known to one of ordinary skill in the art from the description herein.
Draft hood 140 is positioned on top of blower outlet 124. Draft hood 140 is configured to receive the exhaust gas that is blown outward through blower outlet 124. In an exemplary embodiment, draft hood 140 includes a flared portion 142. Flared portion 142 is coupled to a pipe 144. Flared portion 142 opens toward blower outlet 124. Desirably, flared portion 142 is positioned so as to be concentric with blower outlet 124. Pipe 144 extends from the narrow end of flared portion 142 away from water heater 10.
Draft hood 140 may be mounted to blower 120 via one or more mounting structures 146. Mounting structures 146 may include bolts, screws, or any other structure adapted to affix draft hood 140 to blower 120.
As shown in
Venting system 100 may further include a thermal switch 160. Thermal switch 160 is coupled to draft hood 140. Thermal switch 160 is operable to sense a temperature of the air located in relief openings 148. As will be further described herein, thermal switch 160 is calibrated to shut down (or stop the operation of) water heater 10 when thermal switch 160 is senses a temperature above a predetermined limit. Thermal switch 160 includes electrical connections 162 for connecting to, and thereby controlling the operation of, water heater 10.
As shown in
The operation of venting system 100 will now be described with respect to
During this operation, thermal switch 160 senses the temperature of the exhaust gas. Thermal switch 160 has a predetermined limit temperature. This temperature is selected based on safety concerns. The selection of a suitable predetermined limit will be known to one of ordinary skill in the art from the description herein. When thermal switch 160 senses that the air temperature in relief openings 148 exceeds the predetermined limit (for example, if the draft hood 140 were to become blocked), thermal switch 160 sends a shutdown signal to water heater 10 using electrical connections 162. Water heater 10 then stops burning fuel in the combustion chamber, and thereby, stops creating exhaust gas. Water heater 10 may stop burning fuel for a predetermined period of time, or until reset by a user of water heater 10.
The above described system may also form the basis of a kit for venting a water heater in accordance with aspects of the present invention. The kit includes a draft hood configured to be attached to a water heater on top of a blower outlet of the water heater. The draft hood is configured to receive exhaust gas blown through the blower outlet of the water heater. The draft hood of this kit may comprise any of the features described above with respect to draft hood 140.
The kit may further include a thermal switch coupled to the draft hood. The thermal switch is configured to be electrically coupled to the water heater. For example, the thermal switch may include electrical connections adapted to be connected with circuitry of the water heater. The thermal switch of this kit may comprise any of the features described above with respect to thermal switch 160.
In step 210, exhaust gas is blown outward through a blower outlet of the water heater. In an exemplary embodiment, impeller 126 draws exhaust gas inward from the combustion chamber through blower inlet 122, and blows the exhaust gas outward through blower outlet 124.
In step 220, the exhaust gas blown outward through the blower outlet is received with a draft hood positioned on top of the blower outlet. In an exemplary embodiment, draft hood 140 is positioned to receive the exhaust gas blown outward through blower outlet 124.
Method 200 is not limited to the above steps, but may include addition steps as set forth. below.
For example, method 200 may include the step of enabling communication of the exhaust gas blown through the blower outlet with atmosphere surrounding the draft hood. In an exemplary embodiment, draft hood defines relief openings 148 between the flared portion 142 of draft hood 140 and blower 120. During a blocked vent condition, relief openings 148 may enable communication of the exhaust gas blown through blower outlet 124 with the atmosphere surrounding water heater 10 and draft hood 140.
For another example, method 200 may include the steps of sensing a temperature adjacent the draft hood with a thermal switch, and shutting down the water heater when the thermal switch senses a temperature above a predetermined limit. In an exemplary embodiment, thermal switch 160 is coupled to draft hood 140, as described above. When thermal switch 160 senses that the air temperature in relief openings 148 exceeds the predetermined limit, thermal switch 160 sends a shutdown signal to water heater 10 using electrical connections 162.
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
