US20050271989A1 - Draft inducer system - Google Patents
Draft inducer system Download PDFInfo
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- US20050271989A1 US20050271989A1 US11/195,099 US19509905A US2005271989A1 US 20050271989 A1 US20050271989 A1 US 20050271989A1 US 19509905 A US19509905 A US 19509905A US 2005271989 A1 US2005271989 A1 US 2005271989A1
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- Prior art keywords
- voltage
- reducer
- inducer
- housing
- unit
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
- F23L17/00—Inducing draught; Tops for chimneys or ventilating shafts; Terminals for flues
- F23L17/005—Inducing draught; Tops for chimneys or ventilating shafts; Terminals for flues using fans
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2223/00—Signal processing; Details thereof
- F23N2223/08—Microprocessor; Microcomputer
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2225/00—Measuring
- F23N2225/08—Measuring temperature
- F23N2225/10—Measuring temperature stack temperature
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/08—Regulating air supply or draught by power-assisted systems
- F23N3/082—Regulating air supply or draught by power-assisted systems using electronic means
Definitions
- the invention generally relates air movement and, more particularly, the invention relates to draft inducers.
- Fuel burning furnaces commonly have an attached draft inducer that mixes ambient air with exhaust gasses (i.e., fumes) produced by burning fuel. After the exhaust gasses and ambient air are mixed, they are vented from the furnace through an exhaust pipe.
- draft inducers can improve efficiency by controlling the flow of exhaust gasses from their furnaces.
- mixing the ambient air with the exhaust reduces the exhaust temperature, thus permitting simplified piping to be used for the exhaust pipe.
- a draft inducer system has a voltage reducer capable of converting an input AC voltage to a reduced voltage, and an inducer unit capable of being coupled with the voltage reducer.
- the voltage reducer includes a reducer housing, a set of prongs extending from the reducer housing, and an output interface capable of delivering the reduced voltage.
- the set of prongs is capable of plugging into an AC outlet.
- the inducer unit has a unit housing, an air moving device within the unit housing, and a mixing chamber formed by the unit housing.
- the mixing chamber has an exhaust input to receive exhaust from a burning fuel, and an ambient air input for receiving ambient air. The ambient air mixes with the exhaust in the mixing chamber to produce mixed air. Accordingly, the mixing chamber also has a mix output capable of directing the mixed air from the mixing chamber.
- the air moving device includes a DC blower.
- the reducer housing may be produced from a flexible material.
- the voltage reducer also may include a cord that terminates at the output interface, where the output interface is removably coupleable with the inducer unit.
- the voltage reducer also may include a transformer for producing the reduced voltage.
- the inducer unit include rectification circuitry to produce a substantially DC input voltage from the reduced voltage.
- the system may have a hot water heater.
- the unit housing may be mounted to the hot water heater, where the hot water heater burns the fuel to produce the exhaust.
- a draft inducer for controlling the exhaust of a fuel burning system i.e., where the fuel burning system burns fuel after control circuitry that is a part of the system is energized
- a draft inducer for controlling the exhaust of a fuel burning system has an input for receiving power, an air moving device energized by power received from the input, and an output for selectively delivering the power to the control circuitry, which is energized by the power received via the output.
- the output switches the power to the control circuitry on and off as a function of the rotational speed of the air moving device.
- the draft inducer has a switch between the input and the output.
- the switch is configured to provide a closed circuit when the air moving device is operating at least at a predefined speed.
- the switch also may be configured to provide an open circuit when the air moving device is operating below the predefined speed. The open circuit prevents power from being delivered from the output.
- the draft inducer also may have a processor that detects the rotational speed of the air moving device.
- the processor thus produces a power signal when the air moving device rotates at a predetermined rotational speed. Generation of the power signal causes the output to deliver power to the control circuitry.
- a draft inducer system has a voltage reducer capable of converting an input AC voltage to a reduced voltage, and an inducer unit having a housing and an air moving device within the unit housing.
- the voltage reducer has a set of prongs capable of plugging into an AC outlet.
- the inducer unit is removably coupleable with the voltage reducer and is energized by the reduced voltage.
- FIG. 1 schematically shows a draft inducer system that may be configured in accordance with illustrative embodiments of the invention.
- FIG. 2 schematically shows a draft inducer configured in accordance with illustrative embodiments of the invention.
- FIG. 3 schematically shows an external AC adapter that converts AC wall voltage to a reduced AC voltage.
- FIG. 4 schematically shows a bottom view of the draft inducer of FIG. 2 .
- FIG. 5 schematically shows an exploded view of the draft inducer shown in FIG. 2 .
- FIG. 6 schematically shows the electronic configuration and connections between the AC adapter, the draft inducer, and a corresponding hot water heater.
- FIG. 7 shows an exemplary process executed by the electronic circuit shown in FIG. 6 .
- a draft inducer has an external AC adapter that converts AC wall voltage to a reduced AC voltage.
- the adapter has a pair of prongs 34 that readily plug into a conventional AC outlet, such as a wall outlet or power strip. Installation of the draft inducer therefore requires no specialized hard wired electrical connections. Details of this and related embodiments are discussed below.
- a draft inducer has an output that delivers power to a fuel burning system as a function of the rotational speed of its blower. Receipt of the power enables the fuel burning system to perform its underlying function (e.g., burning fuel to deliver heat). Accordingly, as a safety feature, the draft inducer can prevent the system from burning fuel (i.e., producing potentially toxic exhaust gas) when the blower is not operating. Details of this and related embodiments are discussed below.
- FIG. 1 schematically shows a draft inducer system (the “system 10 ”) that may be configured in accordance with illustrative embodiments of the invention.
- the system 10 has a fuel burning device 12 with a draft inducer 14 mounted to its top side.
- the draft inducer 14 forcibly vents exhaust fumes produced by the burning fuel.
- the fuel burning device 12 is a conventional natural gas hot water heater (also identified by reference number 12 ). Accordingly, various embodiments are discussed as being used with a natural gas hot water heater 12 . Rather than having a hot water heater 12 , however, the system 10 may have other types of fuel burning devices, such as boilers. Discussion of a hot water heater 12 thus is exemplary and, consequently, not intended to limit all embodiments of the invention. Moreover, various embodiments may be implemented with other types of burnable fuels, such as oil or wood. Accordingly, discussion of burning natural gas is not intended to limit all embodiments of the invention.
- the draft inducer 14 illustratively is mounted over an exhaust opening in the hot water heater 12 to receive exhaust fumes produced by the burning fuel. In illustrative embodiments, that mounting is between a cold water intake pipe 16 and a hot water outlet pipe 18 at the top of the heater 12 .
- the draft inducer 14 mixes the exhaust fumes with ambient air within its interior, and forces the resultant mixture out of the premises via an exhaust pipe 20 . Because the resultant mixture typically has a much lower temperature than that of the exhaust fumes, the exhaust pipe 20 can be produced from a lower cost material, such as conventional PVC piping.
- the system 10 is powered by an AC adapter 22 that can be plugged into a conventional AC outlet. Accordingly, installation requires no specialized electrical expertise. Details of the draft inducer 14 and its interaction with the hot water heater 12 are discussed below with reference to FIGS. 2-7 .
- FIG. 2 schematically shows a draft inducer 14 configured in accordance with illustrative embodiments of the invention.
- the inducer 14 has a metal or plastic housing 24 containing a blower 25 and forming an exhaust port 26 for directing the noted mixture of exhaust fumes and ambient air to the exhaust pipe 20 .
- the housing 24 also forms an interior mixing chamber 28 for mixing ambient air with exhaust fumes.
- a plurality of ambient air inlets 30 formed in the side of the housing 24 permit the blower 25 to draw ambient air into the mixing chamber 28 , thus enabling the exhaust to mix with the air.
- FIG. 3 schematically shows more details of the external AC adapter 22 , which converts AC wall voltage to a reduced AC voltage.
- the adapter 22 has an adapter housing 32 , a pair of prongs 34 (extending from the adapter housing 32 ) for mating with a wall plug (e.g., a home AC outlet, such as those in North America and Europe, or a power strip), and an internal transformer 36 (see FIG. 6 ) for reducing the wall voltage to a lower (stepped down) AC voltage.
- the adapter housing 32 may be produced from any conventional material used for these purposes, such as a hard or soft plastic.
- the wall voltage is 115 volts AC, while the stepped down voltage is 24 volts AC.
- An electrical cord 38 transmits the stepped down voltage to the draft inducer 14 .
- the cord 38 illustratively plugs into a mating female port 40 (see FIG. 2 ) on the draft inducer 14 .
- the adapter 22 electrically isolates the draft inducer 14 and hot water heater 12 from the power source.
- the adapter 22 enables the system 10 to be installed without requiring specialized hard wired electrical connections.
- the adapter 22 illustratively is removably coupleable with the mating female port 40 on the draft inducer 14 .
- the adapter cord 38 may have a male contact member 42 that plugs into the mating female port 40 noted above. In other embodiments, however, the adapter cord 38 is wired directly into the mating female port 40 and thus, is not removably coupled with the draft inducer 14 .
- FIG. 4 schematically shows a bottom view of the draft inducer 14 shown in FIG. 2 .
- This view more clearly shows an exhaust inlet 44 formed through the bottom of the mixing chamber 28 .
- the size and shape of the exhaust inlet 44 are selected to carefully control the amount of exhaust that can be drawn into the mixing chamber 28 . Those skilled in the art can calculate this size and shape based upon the type of fuel being burned, the performance of the blower 25 , the type of hot water heater 12 , and other related parameters.
- the draft inducer 14 also has a plurality of support bosses 46 underneath the exhaust port 26 . Accordingly, the support bosses 46 provide the structural integrity to the draft inducer 14 , such as when the exhaust pipe 20 is coupled with the exhaust port 26 . Additionally, the draft inducer 14 has a plurality of mounting members 48 for fastening the inducer housing 24 with the hot water heater 12 .
- FIG. 5 schematically shows an exploded view of the draft inducer 14 shown in FIG. 2 .
- the housing 24 illustratively is formed from a top housing portion 24 A that snap fits with a bottom housing portion 24 B.
- the top housing portion 24 A has a pair of male clips 50 that mate with corresponding female clips 52 on the bottom housing portion 24 B.
- Each female clip has a spring body 54 that enables it to flex away from the housing 24 . Consequently, each female clip 52 can easily uncouple from its corresponding male clip 50 .
- the top and bottom housing portions 24 A and 24 B also have a pivot connection 56 that enables the top housing portion 24 A to pivot upwardly (relative to the bottom housing portion 24 B) when the male and female clips 50 and 52 are unlatched.
- the edges of the top and bottom housing portions 24 A and 24 B seal the interior of the housing 24 .
- the edges of the top and bottom housing portions 24 A and 24 B may be formed with a lap joint 58 to align and seal the housing portions 24 A and 24 B. Consequently, other than the noted inlets and outlets, the mixing chamber 28 should have no other vents to the exterior.
- the blower 25 may be easily removed, replaced, or both removed and replaced.
- the blower 25 may be malfunctioning.
- the adapter 22 may be unplugged, the housing portions 24 A and 24 B may be uncoupled, and the blower 25 can be removed.
- the housing 24 may be closed.
- the adapter 22 then may be reconnected to the AC outlet, thus permitting the draft inducer 14 to begin operating.
- the blower 25 is similar to the SPINNAKERTM blower, distributed by Comair Rotron of San Diego, Calif. In alternative embodiments, other air moving devices may be used, such as fans.
- FIG. 6 schematically shows the general electronic configuration and connections between the adapter 22 , the draft inducer 14 , and the hot water heater 12 .
- the various parts of the system 10 are divided by vertical dashed lines.
- relevant components of the adapter 22 are shown and identified by reference number 22
- relevant components of the draft inducer 14 i.e., noted as being within the housing 24 and/or exhaust pipe 20
- relevant components of the heater 12 are shown and identified by reference number 12 .
- the adapter 22 includes an interface 60 (e.g., the prongs 34 ) for receiving the wall voltage (e.g., 115 volts AC), and the prior noted step-down transformer 36 for producing a stepped-down AC voltage (e.g., 24 volts AC).
- the stepped-down voltage then is fed to a bridge rectifier 64 (within the draft inducer housing 24 ), which converts the stepped-down AC voltage to a DC voltage (e.g., 24 volts DC).
- the bridge rectifier 64 may be located within the adapter 22 .
- the draft inducer 14 also includes a first capacitor C 1 (in parallel with the blower 25 ) that reduces ripple from the bridge rectifier 64 and stores the DC voltage received from the bridge rectifier 64 .
- a second capacitor C 2 in series with the first capacitor C 1 provides noise suppression. More specifically, the second capacitor C 2 protects a downstream switch 76 (discussed below) from arcing as it opens and closes. The second capacitor C 2 does not provide any appreciable filtering. Accordingly, the capacitance of the first capacitor C 1 may be selected to be much greater than that of the second capacitor C 2 .
- the capacitance of the first capacitor C 1 can be on the order of about 10,000 microfarads, while the capacitance of the second capacitor C 2 can be on the order of about 0.1 microfarads.
- the second capacitor C 2 is omitted.
- the blower 25 may include one or more program leads (shown schematically at reference number 66 ) that permit it to perform in pre-specified ways.
- the blower 25 may be programmed to rotate at a speed (i.e., in RPMs) that is based upon the temperature of the exhaust fumes.
- the blower 25 may include hardware and/or software that perform the noted functions.
- the blower 25 may include a processor 68 that executes a specified function based upon computer instructions. Different hardware within the blower 25 also may be configured to perform the noted functions.
- the blower 25 includes internal circuitry (e.g., the processor 68 ) that produces a signal having a zero output state (e.g., logic level of zero) when the blower 25 is running (i.e., rotating at or above a pre-selected RPM value), and an open output state (e.g., logic level one) when the blower 25 is not running.
- This signal is transmitted directly to a switch 69 (via a resistor R 1 ) that, consequently, is open when the blower 25 is off, and closed when the blower 25 is on.
- the switch 69 is a PNP bipolar junction transistor (“BJT”) that is biased on when its base receives the noted zero output state.
- the draft inducer 14 also includes a thermistor sensor 70 (shown in FIG. 3 as a “PTC 70 ”), which has a variable resistance that is proportional to the current through it (i.e., it acts as a reusable fuse), and an over temperature switch (“OTS 72 ”) to ensure that the temperature of the exhaust/air mixture in the exhaust port 26 does not exceed a prescribed temperature. To that end, if the OTS 72 detects that the mixture exceeds such temperature, it opens, thus breaking the circuit to the heater 12 . As a consequence, the heater 12 cannot continue to operate.
- PTC 70 thermistor sensor 70
- OTS 72 over temperature switch
- the heater 12 has a solenoid 74 that turns on the gas supply when on, and turns off the gas supply when off. Accordingly, when either the OTS 72 or switch 69 breaks the circuit, the solenoid 74 cannot function, consequently cutting off the supply of gas to the heater 12 . Consequently, the heater 12 cannot burn gas, which produces exhaust fumes.
- the heater 12 also includes a low temperature switch (“LTS 76 ”), which selectively turns the heater 12 on and off based upon water temperature within the tank. Specifically, the LTS 76 turns the heater 12 on (i.e., it closes) when it detects that the water temperature is below a pre-selected low temperature. In a corresponding manner, the LTS 76 turns the heater 12 off (i.e., it opens) when it detects that the water temperature is at or above a pre-selected high temperature.
- LTS 76 low temperature switch
- FIG. 7 shows an exemplary process executed by the electronic circuit shown in FIG. 6 .
- the process begins at step 700 , in which the low temperature switch 42 is closed to begin heating water in the tank. This connection provides the ground return for the blower 25 , which causes it to begin rotating.
- step 702 It then is determined at step 702 if the blower 25 is running at a predetermined minimum speed that can provide a sufficient pressure to perform the draft inducing function.
- This predetermined speed may be based upon a number of variables, such as the size of the hot water heater 12 , the size of the blower 25 and inducer 14 , and other known parameters associated with the system 10 .
- the processor 68 makes this determination. The hot water heater 12 thus receives no power until the blower 25 reaches this minimum speed.
- step 704 in which the solenoid 74 is connected to the power source.
- the processor 68 forwards a signal to the switch 69 (e.g., a logical zero).
- the switch 69 closes, which connects the power source (i.e., the transformer 36 and rectifier 64 ) with the solenoid 74 . Consequently, the solenoid 74 turns on the gas supply, which enables the hot water heater 12 to begin heating the water in its internal tank.
- the hot water heater 12 continues to heat the water until it reaches a predetermined maximum temperature (step 706 ). When that temperature is reached, the hot water heater 12 opens its low temperature switch 46 (step 708 ), which effectively breaks the return path for the rectifier 64 . As suggested above, due to its small capacitance, the second capacitor C 2 does not provide a ground return path for the rectifier 64 .
- step 710 The water in the hot water heater 12 then cools until it reaches a predetermined minimum temperature (step 710 ). After it reaches the minimum temperature, the process repeats by looping back to step 700 , in which the low temperature switch 700 is closed.
- this process can be interrupted at any time for several reasons. Primarily, if the blower 25 malfunctions by not rotating rapidly enough, the switch 69 opens, which stops the hot water heater 12 from burning its fuel. In other words, if the blower 25 does not reach its predetermined speed, then the entire system 10 effectively shuts down. In such case, the blower 25 may be replaced in the manner discussed above. If the various parameters are properly selected, then this feature should help prevent the hot water heater 12 from generating more exhaust fumes than the inducer 14 can force from the system 10 . The process also can be interrupted if the PTC 70 trips, which happens when the hot water heater 12 draws too much current, or if the air/exhaust mixture is too hot, which causes the over temperature switch 42 to open.
- the draft inducer 14 provides a number of other advantages over many conventional draft inducers. Specifically, the draft inducer 14 requires a smaller blower 25 than many prior art draft inducers. As noted above, in illustrative embodiments, the blower 25 runs at 24 volts DC, while many available prior art blowers run at 115 volts AC. Consequently, the draft inducer 14 should have a lower power draw and a smaller profile. This smaller draft inducer 14 thus should generate less noise. Some of these advantages are enhanced with the embodiment that incorporates an external step-down transformer 36 .
- the draft inducer 14 is more versatile than prior art draft inducers having AC blowers. Specifically, because a DC blower is used, the draft inducer 14 may be programmed. Moreover, the embodiment with a remote step-down transformer 36 permits easy installation that typically should not require an electrician.
- the draft inducer 14 can have a battery backup.
- the battery can bypass transformer 36 and rectifier 64 . Accordingly, if there is a power failure, the battery can power the system 10 .
Abstract
A draft inducer system has a voltage reducer capable of converting an input AC voltage to a reduced voltage, and an inducer unit capable of being coupled with the voltage reducer. The voltage reducer includes a reducer housing, a set of prongs extending from the reducer housing, and an output interface capable of delivering the reduced voltage. The set of prongs is capable of plugging into an AC outlet. The inducer unit has a unit housing, an air moving device within the unit housing, and a mixing chamber formed by the unit housing. The mixing chamber has an exhaust input to receive exhaust from a burning fuel, and an ambient air input for receiving ambient air. The ambient air mixes with the exhaust in the mixing chamber to produce mixed air. Accordingly, the mixing chamber also has a mix output capable of directing the mixed air from the mixing chamber.
Description
- This patent application is a continuation application and claims priority from U.S. patent application Ser. No. 10/655,534, filed on Sep. 4, 2003 entitled “DRAFT INDUCER SYSTEM” that is incorporated herein by reference. Application Ser. No. 10/655,534 claims priority from provisional U.S. patent application No. 60/409,142, filed Sep. 9, 2002, entitled, “DRAFT INDUCER SYSTEM,” and naming Fred A. Brown, Phillip Bowen, and Jeffrey E. From as inventors, the disclosure of which is incorporated herein, in its entirety, by reference. Application Ser. No. 10/655,534 also claims priority from the provisional U.S. patent application No. 60/499,844 filed on Sep. 3, 2003, entitled, “DYNAMIC DRAFT INDUCER” and naming Fred A. Br own and Gregory R. Turi as inventors, the disclosure of which is incorporated herein, in its entirety, by reference.
- The invention generally relates air movement and, more particularly, the invention relates to draft inducers.
- Fuel burning furnaces commonly have an attached draft inducer that mixes ambient air with exhaust gasses (i.e., fumes) produced by burning fuel. After the exhaust gasses and ambient air are mixed, they are vented from the furnace through an exhaust pipe. Among other benefits, draft inducers can improve efficiency by controlling the flow of exhaust gasses from their furnaces. Moreover, mixing the ambient air with the exhaust reduces the exhaust temperature, thus permitting simplified piping to be used for the exhaust pipe.
- Many conventional draft inducers have an AC blower that is powered by a high voltage AC signal (e.g., 115 volts AC). As a result, such draft inducers typically are relatively large, have relatively high power consumption requirements, and run less efficiently. Moreover, for a number of reasons relating to the AC blower, local building codes often require that an electrician install the inducer, further increasing installation costs.
- In accordance with one aspect of the invention, a draft inducer system has a voltage reducer capable of converting an input AC voltage to a reduced voltage, and an inducer unit capable of being coupled with the voltage reducer. The voltage reducer includes a reducer housing, a set of prongs extending from the reducer housing, and an output interface capable of delivering the reduced voltage. The set of prongs is capable of plugging into an AC outlet. The inducer unit has a unit housing, an air moving device within the unit housing, and a mixing chamber formed by the unit housing. The mixing chamber has an exhaust input to receive exhaust from a burning fuel, and an ambient air input for receiving ambient air. The ambient air mixes with the exhaust in the mixing chamber to produce mixed air. Accordingly, the mixing chamber also has a mix output capable of directing the mixed air from the mixing chamber.
- In some embodiments, the air moving device includes a DC blower. Moreover, the reducer housing may be produced from a flexible material. The voltage reducer also may include a cord that terminates at the output interface, where the output interface is removably coupleable with the inducer unit. The voltage reducer also may include a transformer for producing the reduced voltage.
- Various embodiments of the inducer unit include rectification circuitry to produce a substantially DC input voltage from the reduced voltage. Moreover, the system may have a hot water heater. In such case, the unit housing may be mounted to the hot water heater, where the hot water heater burns the fuel to produce the exhaust.
- In accordance with another aspect of the invention, a draft inducer for controlling the exhaust of a fuel burning system (i.e., where the fuel burning system burns fuel after control circuitry that is a part of the system is energized) has an input for receiving power, an air moving device energized by power received from the input, and an output for selectively delivering the power to the control circuitry, which is energized by the power received via the output. The output switches the power to the control circuitry on and off as a function of the rotational speed of the air moving device.
- In some embodiments, the draft inducer has a switch between the input and the output. The switch is configured to provide a closed circuit when the air moving device is operating at least at a predefined speed. The switch also may be configured to provide an open circuit when the air moving device is operating below the predefined speed. The open circuit prevents power from being delivered from the output.
- The draft inducer also may have a processor that detects the rotational speed of the air moving device. The processor thus produces a power signal when the air moving device rotates at a predetermined rotational speed. Generation of the power signal causes the output to deliver power to the control circuitry.
- In accordance with other aspects of the invention, a draft inducer system has a voltage reducer capable of converting an input AC voltage to a reduced voltage, and an inducer unit having a housing and an air moving device within the unit housing. The voltage reducer has a set of prongs capable of plugging into an AC outlet. In addition, the inducer unit is removably coupleable with the voltage reducer and is energized by the reduced voltage.
- The foregoing and advantages of the invention will be appreciated more fully from the following further description thereof with reference to the accompanying drawings wherein:
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FIG. 1 schematically shows a draft inducer system that may be configured in accordance with illustrative embodiments of the invention. -
FIG. 2 schematically shows a draft inducer configured in accordance with illustrative embodiments of the invention. -
FIG. 3 schematically shows an external AC adapter that converts AC wall voltage to a reduced AC voltage. -
FIG. 4 schematically shows a bottom view of the draft inducer ofFIG. 2 . -
FIG. 5 schematically shows an exploded view of the draft inducer shown inFIG. 2 . -
FIG. 6 schematically shows the electronic configuration and connections between the AC adapter, the draft inducer, and a corresponding hot water heater. -
FIG. 7 shows an exemplary process executed by the electronic circuit shown inFIG. 6 . - In illustrative embodiments of the invention, a draft inducer has an external AC adapter that converts AC wall voltage to a reduced AC voltage. To those ends, the adapter has a pair of
prongs 34 that readily plug into a conventional AC outlet, such as a wall outlet or power strip. Installation of the draft inducer therefore requires no specialized hard wired electrical connections. Details of this and related embodiments are discussed below. - In other embodiments, a draft inducer has an output that delivers power to a fuel burning system as a function of the rotational speed of its blower. Receipt of the power enables the fuel burning system to perform its underlying function (e.g., burning fuel to deliver heat). Accordingly, as a safety feature, the draft inducer can prevent the system from burning fuel (i.e., producing potentially toxic exhaust gas) when the blower is not operating. Details of this and related embodiments are discussed below.
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FIG. 1 schematically shows a draft inducer system (the “system 10”) that may be configured in accordance with illustrative embodiments of the invention. Thesystem 10 has afuel burning device 12 with adraft inducer 14 mounted to its top side. Among other things, the draft inducer 14 forcibly vents exhaust fumes produced by the burning fuel. - In illustrative embodiments, the
fuel burning device 12 is a conventional natural gas hot water heater (also identified by reference number 12). Accordingly, various embodiments are discussed as being used with a natural gashot water heater 12. Rather than having ahot water heater 12, however, thesystem 10 may have other types of fuel burning devices, such as boilers. Discussion of ahot water heater 12 thus is exemplary and, consequently, not intended to limit all embodiments of the invention. Moreover, various embodiments may be implemented with other types of burnable fuels, such as oil or wood. Accordingly, discussion of burning natural gas is not intended to limit all embodiments of the invention. - The
draft inducer 14 illustratively is mounted over an exhaust opening in thehot water heater 12 to receive exhaust fumes produced by the burning fuel. In illustrative embodiments, that mounting is between a coldwater intake pipe 16 and a hotwater outlet pipe 18 at the top of theheater 12. When thesystem 10 is on, thedraft inducer 14 mixes the exhaust fumes with ambient air within its interior, and forces the resultant mixture out of the premises via anexhaust pipe 20. Because the resultant mixture typically has a much lower temperature than that of the exhaust fumes, theexhaust pipe 20 can be produced from a lower cost material, such as conventional PVC piping. - The
system 10 is powered by anAC adapter 22 that can be plugged into a conventional AC outlet. Accordingly, installation requires no specialized electrical expertise. Details of thedraft inducer 14 and its interaction with thehot water heater 12 are discussed below with reference toFIGS. 2-7 . -
FIG. 2 schematically shows adraft inducer 14 configured in accordance with illustrative embodiments of the invention. Theinducer 14 has a metal orplastic housing 24 containing ablower 25 and forming anexhaust port 26 for directing the noted mixture of exhaust fumes and ambient air to theexhaust pipe 20. Thehousing 24 also forms aninterior mixing chamber 28 for mixing ambient air with exhaust fumes. A plurality ofambient air inlets 30 formed in the side of thehousing 24 permit theblower 25 to draw ambient air into the mixingchamber 28, thus enabling the exhaust to mix with the air. -
FIG. 3 schematically shows more details of theexternal AC adapter 22, which converts AC wall voltage to a reduced AC voltage. Specifically, theadapter 22 has anadapter housing 32, a pair of prongs 34 (extending from the adapter housing 32) for mating with a wall plug (e.g., a home AC outlet, such as those in North America and Europe, or a power strip), and an internal transformer 36 (seeFIG. 6 ) for reducing the wall voltage to a lower (stepped down) AC voltage. Theadapter housing 32 may be produced from any conventional material used for these purposes, such as a hard or soft plastic. - In exemplary embodiments, the wall voltage is 115 volts AC, while the stepped down voltage is 24 volts AC. An
electrical cord 38 transmits the stepped down voltage to thedraft inducer 14. To that end, thecord 38 illustratively plugs into a mating female port 40 (seeFIG. 2 ) on thedraft inducer 14. Among other benefits, theadapter 22 electrically isolates thedraft inducer 14 andhot water heater 12 from the power source. In addition, as noted above, theadapter 22 enables thesystem 10 to be installed without requiring specialized hard wired electrical connections. - The
adapter 22 illustratively is removably coupleable with the matingfemale port 40 on thedraft inducer 14. To that end, theadapter cord 38 may have amale contact member 42 that plugs into the matingfemale port 40 noted above. In other embodiments, however, theadapter cord 38 is wired directly into the matingfemale port 40 and thus, is not removably coupled with thedraft inducer 14. -
FIG. 4 schematically shows a bottom view of thedraft inducer 14 shown inFIG. 2 . This view more clearly shows anexhaust inlet 44 formed through the bottom of the mixingchamber 28. The size and shape of theexhaust inlet 44 are selected to carefully control the amount of exhaust that can be drawn into the mixingchamber 28. Those skilled in the art can calculate this size and shape based upon the type of fuel being burned, the performance of theblower 25, the type ofhot water heater 12, and other related parameters. - For extra support, the
draft inducer 14 also has a plurality ofsupport bosses 46 underneath theexhaust port 26. Accordingly, thesupport bosses 46 provide the structural integrity to thedraft inducer 14, such as when theexhaust pipe 20 is coupled with theexhaust port 26. Additionally, thedraft inducer 14 has a plurality of mountingmembers 48 for fastening theinducer housing 24 with thehot water heater 12. -
FIG. 5 schematically shows an exploded view of thedraft inducer 14 shown inFIG. 2 . As shown, thehousing 24 illustratively is formed from atop housing portion 24A that snap fits with abottom housing portion 24B. To those ends, thetop housing portion 24A has a pair ofmale clips 50 that mate with correspondingfemale clips 52 on thebottom housing portion 24B. Each female clip has aspring body 54 that enables it to flex away from thehousing 24. Consequently, eachfemale clip 52 can easily uncouple from its correspondingmale clip 50. The top andbottom housing portions top housing portion 24A to pivot upwardly (relative to thebottom housing portion 24B) when the male andfemale clips - When coupled, the edges of the top and
bottom housing portions housing 24. To that end, the edges of the top andbottom housing portions housing portions chamber 28 should have no other vents to the exterior. - When the two
housing portions blower 25 may be easily removed, replaced, or both removed and replaced. For example, theblower 25 may be malfunctioning. In such case, theadapter 22 may be unplugged, thehousing portions blower 25 can be removed. After anew blower 25 is positioned in its interior (e.g., via another snap-fit), thehousing 24 may be closed. Theadapter 22 then may be reconnected to the AC outlet, thus permitting thedraft inducer 14 to begin operating. In illustrative embodiments, theblower 25 is similar to the SPINNAKER™ blower, distributed by Comair Rotron of San Diego, Calif. In alternative embodiments, other air moving devices may be used, such as fans. -
FIG. 6 schematically shows the general electronic configuration and connections between theadapter 22, thedraft inducer 14, and thehot water heater 12. The various parts of thesystem 10 are divided by vertical dashed lines. In particular, relevant components of theadapter 22 are shown and identified byreference number 22, relevant components of the draft inducer 14 (i.e., noted as being within thehousing 24 and/or exhaust pipe 20) are shown and identified byreference number 14, and relevant components of theheater 12 are shown and identified byreference number 12. - The
adapter 22 includes an interface 60 (e.g., the prongs 34) for receiving the wall voltage (e.g., 115 volts AC), and the prior noted step-downtransformer 36 for producing a stepped-down AC voltage (e.g., 24 volts AC). The stepped-down voltage then is fed to a bridge rectifier 64 (within the draft inducer housing 24), which converts the stepped-down AC voltage to a DC voltage (e.g., 24 volts DC). In alternative embodiments, rather than being within thedraft inducer 14, thebridge rectifier 64 may be located within theadapter 22. - The
draft inducer 14 also includes a first capacitor C1 (in parallel with the blower 25) that reduces ripple from thebridge rectifier 64 and stores the DC voltage received from thebridge rectifier 64. A second capacitor C2 in series with the first capacitor C1 provides noise suppression. More specifically, the second capacitor C2 protects a downstream switch 76 (discussed below) from arcing as it opens and closes. The second capacitor C2 does not provide any appreciable filtering. Accordingly, the capacitance of the first capacitor C1 may be selected to be much greater than that of the second capacitor C2. For example, the capacitance of the first capacitor C1 can be on the order of about 10,000 microfarads, while the capacitance of the second capacitor C2 can be on the order of about 0.1 microfarads. In alternative embodiments, the second capacitor C2 is omitted. - The
blower 25 may include one or more program leads (shown schematically at reference number 66) that permit it to perform in pre-specified ways. For example, theblower 25 may be programmed to rotate at a speed (i.e., in RPMs) that is based upon the temperature of the exhaust fumes. To that end, theblower 25 may include hardware and/or software that perform the noted functions. For example, theblower 25 may include aprocessor 68 that executes a specified function based upon computer instructions. Different hardware within theblower 25 also may be configured to perform the noted functions. - The
blower 25 includes internal circuitry (e.g., the processor 68) that produces a signal having a zero output state (e.g., logic level of zero) when theblower 25 is running (i.e., rotating at or above a pre-selected RPM value), and an open output state (e.g., logic level one) when theblower 25 is not running. This signal is transmitted directly to a switch 69 (via a resistor R1) that, consequently, is open when theblower 25 is off, and closed when theblower 25 is on. In illustrative embodiments, theswitch 69 is a PNP bipolar junction transistor (“BJT”) that is biased on when its base receives the noted zero output state. - The
draft inducer 14 also includes a thermistor sensor 70 (shown inFIG. 3 as a “PTC 70”), which has a variable resistance that is proportional to the current through it (i.e., it acts as a reusable fuse), and an over temperature switch (“OTS 72”) to ensure that the temperature of the exhaust/air mixture in theexhaust port 26 does not exceed a prescribed temperature. To that end, if theOTS 72 detects that the mixture exceeds such temperature, it opens, thus breaking the circuit to theheater 12. As a consequence, theheater 12 cannot continue to operate. - The
heater 12 has asolenoid 74 that turns on the gas supply when on, and turns off the gas supply when off. Accordingly, when either theOTS 72 or switch 69 breaks the circuit, thesolenoid 74 cannot function, consequently cutting off the supply of gas to theheater 12. Consequently, theheater 12 cannot burn gas, which produces exhaust fumes. - The
heater 12 also includes a low temperature switch (“LTS 76”), which selectively turns theheater 12 on and off based upon water temperature within the tank. Specifically, theLTS 76 turns theheater 12 on (i.e., it closes) when it detects that the water temperature is below a pre-selected low temperature. In a corresponding manner, theLTS 76 turns theheater 12 off (i.e., it opens) when it detects that the water temperature is at or above a pre-selected high temperature. -
FIG. 7 shows an exemplary process executed by the electronic circuit shown inFIG. 6 . The process begins atstep 700, in which thelow temperature switch 42 is closed to begin heating water in the tank. This connection provides the ground return for theblower 25, which causes it to begin rotating. - It then is determined at
step 702 if theblower 25 is running at a predetermined minimum speed that can provide a sufficient pressure to perform the draft inducing function. This predetermined speed may be based upon a number of variables, such as the size of thehot water heater 12, the size of theblower 25 andinducer 14, and other known parameters associated with thesystem 10. In illustrative embodiments, theprocessor 68 makes this determination. Thehot water heater 12 thus receives no power until theblower 25 reaches this minimum speed. - After the
blower 25 reaches the minimum speed, the process continues to step 704, in which thesolenoid 74 is connected to the power source. To that end, theprocessor 68 forwards a signal to the switch 69 (e.g., a logical zero). Upon receipt, theswitch 69 closes, which connects the power source (i.e., thetransformer 36 and rectifier 64) with thesolenoid 74. Consequently, thesolenoid 74 turns on the gas supply, which enables thehot water heater 12 to begin heating the water in its internal tank. - The
hot water heater 12 continues to heat the water until it reaches a predetermined maximum temperature (step 706). When that temperature is reached, thehot water heater 12 opens its low temperature switch 46 (step 708), which effectively breaks the return path for therectifier 64. As suggested above, due to its small capacitance, the second capacitor C2 does not provide a ground return path for therectifier 64. - The water in the
hot water heater 12 then cools until it reaches a predetermined minimum temperature (step 710). After it reaches the minimum temperature, the process repeats by looping back to step 700, in which thelow temperature switch 700 is closed. - It should be noted that this process can be interrupted at any time for several reasons. Primarily, if the
blower 25 malfunctions by not rotating rapidly enough, theswitch 69 opens, which stops thehot water heater 12 from burning its fuel. In other words, if theblower 25 does not reach its predetermined speed, then theentire system 10 effectively shuts down. In such case, theblower 25 may be replaced in the manner discussed above. If the various parameters are properly selected, then this feature should help prevent thehot water heater 12 from generating more exhaust fumes than theinducer 14 can force from thesystem 10. The process also can be interrupted if thePTC 70 trips, which happens when thehot water heater 12 draws too much current, or if the air/exhaust mixture is too hot, which causes the overtemperature switch 42 to open. - In addition to those discussed above, the
draft inducer 14 provides a number of other advantages over many conventional draft inducers. Specifically, thedraft inducer 14 requires asmaller blower 25 than many prior art draft inducers. As noted above, in illustrative embodiments, theblower 25 runs at 24 volts DC, while many available prior art blowers run at 115 volts AC. Consequently, thedraft inducer 14 should have a lower power draw and a smaller profile. Thissmaller draft inducer 14 thus should generate less noise. Some of these advantages are enhanced with the embodiment that incorporates an external step-downtransformer 36. - The
draft inducer 14 is more versatile than prior art draft inducers having AC blowers. Specifically, because a DC blower is used, thedraft inducer 14 may be programmed. Moreover, the embodiment with a remote step-downtransformer 36 permits easy installation that typically should not require an electrician. - Moreover, in some embodiments, the
draft inducer 14 can have a battery backup. In such case, the battery can bypasstransformer 36 andrectifier 64. Accordingly, if there is a power failure, the battery can power thesystem 10. - Although various exemplary embodiments of the invention are disclosed above, it should be apparent that those skilled in the art can make various changes and modifications that will achieve some of the advantages of the invention without departing from the true scope of the invention.
Claims (10)
1. A draft inducer system comprising:
a voltage reducer capable of converting an input AC voltage to a reduced DC voltage, the voltage reducer comprising:
a reducer housing;
a set of prongs extending from the reducer housing, the set of prongs capable of plugging into an AC outlet; and
an output interface capable of delivering the reduced DC voltage, the system also including an inducer unit capable of being coupled with the output interface, the inducer unit comprising:
a unit housing;
an air moving device including a DC blower within the unit housing receiving the DC voltage; and
a mixing chamber formed by the unit housing, the mixing chamber having an exhaust input to receive exhaust from a burning fuel, the mixing chamber also having an ambient air input for receiving ambient air, the ambient air mixing with the exhaust in the mixing chamber to produce mixed air, the mixing chamber also having a mix output capable of directing the mixed air from the mixing chamber.
2. The system as defined by claim 1 wherein the reducer housing is comprised of a flexible material.
3. The system as defined by claim 1 wherein the voltage reducer includes a transformer for producing the reduced voltage.
4. The system as defined by claim 1 further including a hot water heater, the unit housing being mounted to the hot water heater, the hot water heater burning the fuel to produce the exhaust.
5. The draft inducer as defined by claim 1 further including a switch between the input and the output, the switch being configured to provide a closed circuit when the air moving device is operating at least at a predefined speed.
6. The draft inducer as defined by claim 9 wherein the switch is configured to provide an open circuit when the air moving device is operating below the predefined speed, the open circuit preventing power from being delivered from the output.
7. A draft inducer system comprising:
a voltage reducer capable of converting an input AC voltage to a reduced voltage, the voltage reducer having a set of prongs capable of plugging into an AC outlet; and
an inducer unit having a unit housing and an air moving device within the unit housing, the inducer unit being removably coupleable with the voltage reducer, the inducer unit being energized by the reduced voltage.
8. The system as defined by claim 7 wherein the voltage reducer has a cord that terminates in an output interface, further wherein the inducer unit has a power input that is removably coupleable with the output interface of the voltage reducer.
9. The system as defined by claim 7 wherein the voltage reducer has a reducer housing that contains voltage reduction circuitry.
10. The system as defined by claim 7 wherein the reduced voltage is an AC voltage, the inducer including rectification circuitry to convert the reduced voltage to a DC voltage.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/195,099 US20050271989A1 (en) | 2002-09-09 | 2005-08-02 | Draft inducer system |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US40914202P | 2002-09-09 | 2002-09-09 | |
US49984403P | 2003-09-03 | 2003-09-03 | |
US10/655,534 US7052271B2 (en) | 2002-09-09 | 2003-09-04 | Draft inducer system |
US11/195,099 US20050271989A1 (en) | 2002-09-09 | 2005-08-02 | Draft inducer system |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/655,534 Continuation US7052271B2 (en) | 2002-09-09 | 2003-09-04 | Draft inducer system |
Publications (1)
Publication Number | Publication Date |
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US20050271989A1 true US20050271989A1 (en) | 2005-12-08 |
Family
ID=31982367
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
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US10/655,534 Expired - Fee Related US7052271B2 (en) | 2002-09-09 | 2003-09-04 | Draft inducer system |
US11/195,099 Abandoned US20050271989A1 (en) | 2002-09-09 | 2005-08-02 | Draft inducer system |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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US10/655,534 Expired - Fee Related US7052271B2 (en) | 2002-09-09 | 2003-09-04 | Draft inducer system |
Country Status (5)
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US (2) | US7052271B2 (en) |
AU (1) | AU2003268483A1 (en) |
CA (1) | CA2497992A1 (en) |
GB (1) | GB2410318A (en) |
WO (1) | WO2004023041A2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7363882B2 (en) * | 2002-09-09 | 2008-04-29 | Comair Rotron, Inc. | Condensation removal for use with a draft inducer |
US20050252213A1 (en) * | 2004-05-17 | 2005-11-17 | Brown Fred A | Condensation removal for use with a draft inducer |
CA2541945A1 (en) * | 2003-09-03 | 2005-03-17 | Comair Rotron, Inc. | Apparatus and method for maintaining an operating condition for a blower |
US20120222834A1 (en) * | 2011-03-01 | 2012-09-06 | International Thermal Investments Ltd. | Shroud for space heater |
Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4523079A (en) * | 1983-09-20 | 1985-06-11 | Black & Decker Inc. | Electric iron having electronic control circuit with a power resistor mounted on the soleplate |
US4867106A (en) * | 1985-06-07 | 1989-09-19 | Bradford White Corporation | Direct power vented water heater |
US5075608A (en) * | 1974-06-24 | 1991-12-24 | Erdman David M | Control system, electronically commutated motor system, draft inducer apparatus and method |
US5199385A (en) * | 1992-03-24 | 1993-04-06 | Bradford-White Corp. | Through the wall vented water heater |
US5222888A (en) * | 1991-08-21 | 1993-06-29 | Emerson Electric Co. | Advanced proof-of-rotation switch |
US5288303A (en) * | 1992-04-07 | 1994-02-22 | Wilhelm Environmental Technologies, Inc. | Flue gas conditioning system |
US5352099A (en) * | 1992-12-14 | 1994-10-04 | Ametek, Inc. | Exhaust fan for water heater |
US5524556A (en) * | 1995-06-09 | 1996-06-11 | Texas Instruments Incorporated | Induced draft fan control for use with gas furnaces |
US5589760A (en) * | 1995-09-05 | 1996-12-31 | Lee; Anthony | Traveller's voltage converter for automatically selecting load wattage |
US5791763A (en) * | 1996-04-01 | 1998-08-11 | Go-Gro Industries Limited | Electronic control battery-operated device of lamp with fan |
US5950573A (en) * | 1998-10-16 | 1999-09-14 | Srp 687 Pty. Ltd. | Power vented water heater with air inlet |
US6231311B1 (en) * | 1999-09-17 | 2001-05-15 | Fasco Industries, Inc. | Method and apparatus for providing dilution air to a blower motor |
US6398512B2 (en) * | 1999-09-17 | 2002-06-04 | Dale Stewart | Method and apparatus for cooling and expelling exhaust gases from a water heater |
US6459575B1 (en) * | 2001-05-15 | 2002-10-01 | Hewlett-Packard Company | Cooling module for portable computer |
US6479957B1 (en) * | 1992-04-06 | 2002-11-12 | General Electric Company | Integral motor and control |
US6762866B2 (en) * | 2001-12-03 | 2004-07-13 | Lockheed Martin Corporation | High speed mechanical laser shutter |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07216959A (en) * | 1994-01-27 | 1995-08-15 | Inax Corp | Deodorizing device for toilet |
JPH11177266A (en) * | 1997-12-15 | 1999-07-02 | Pfu Ltd | Cooling device for portable electronic equipment |
-
2003
- 2003-09-04 US US10/655,534 patent/US7052271B2/en not_active Expired - Fee Related
- 2003-09-04 GB GB0507087A patent/GB2410318A/en not_active Withdrawn
- 2003-09-04 CA CA002497992A patent/CA2497992A1/en not_active Abandoned
- 2003-09-04 WO PCT/US2003/027814 patent/WO2004023041A2/en not_active Application Discontinuation
- 2003-09-04 AU AU2003268483A patent/AU2003268483A1/en not_active Abandoned
-
2005
- 2005-08-02 US US11/195,099 patent/US20050271989A1/en not_active Abandoned
Patent Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5075608A (en) * | 1974-06-24 | 1991-12-24 | Erdman David M | Control system, electronically commutated motor system, draft inducer apparatus and method |
US4523079A (en) * | 1983-09-20 | 1985-06-11 | Black & Decker Inc. | Electric iron having electronic control circuit with a power resistor mounted on the soleplate |
US4867106A (en) * | 1985-06-07 | 1989-09-19 | Bradford White Corporation | Direct power vented water heater |
US5222888A (en) * | 1991-08-21 | 1993-06-29 | Emerson Electric Co. | Advanced proof-of-rotation switch |
US5199385A (en) * | 1992-03-24 | 1993-04-06 | Bradford-White Corp. | Through the wall vented water heater |
US6479957B1 (en) * | 1992-04-06 | 2002-11-12 | General Electric Company | Integral motor and control |
US5288303A (en) * | 1992-04-07 | 1994-02-22 | Wilhelm Environmental Technologies, Inc. | Flue gas conditioning system |
US5352099A (en) * | 1992-12-14 | 1994-10-04 | Ametek, Inc. | Exhaust fan for water heater |
US5524556A (en) * | 1995-06-09 | 1996-06-11 | Texas Instruments Incorporated | Induced draft fan control for use with gas furnaces |
US5720231A (en) * | 1995-06-09 | 1998-02-24 | Texas Instrument Incorporated | Induced draft fan control for use with gas furnaces |
US5589760A (en) * | 1995-09-05 | 1996-12-31 | Lee; Anthony | Traveller's voltage converter for automatically selecting load wattage |
US5791763A (en) * | 1996-04-01 | 1998-08-11 | Go-Gro Industries Limited | Electronic control battery-operated device of lamp with fan |
US5950573A (en) * | 1998-10-16 | 1999-09-14 | Srp 687 Pty. Ltd. | Power vented water heater with air inlet |
US6231311B1 (en) * | 1999-09-17 | 2001-05-15 | Fasco Industries, Inc. | Method and apparatus for providing dilution air to a blower motor |
US6398512B2 (en) * | 1999-09-17 | 2002-06-04 | Dale Stewart | Method and apparatus for cooling and expelling exhaust gases from a water heater |
US6459575B1 (en) * | 2001-05-15 | 2002-10-01 | Hewlett-Packard Company | Cooling module for portable computer |
US6762866B2 (en) * | 2001-12-03 | 2004-07-13 | Lockheed Martin Corporation | High speed mechanical laser shutter |
Also Published As
Publication number | Publication date |
---|---|
WO2004023041A2 (en) | 2004-03-18 |
WO2004023041A3 (en) | 2004-11-25 |
US7052271B2 (en) | 2006-05-30 |
GB2410318A (en) | 2005-07-27 |
CA2497992A1 (en) | 2004-03-18 |
AU2003268483A8 (en) | 2004-03-29 |
AU2003268483A1 (en) | 2004-03-29 |
US20040129264A1 (en) | 2004-07-08 |
GB0507087D0 (en) | 2005-05-11 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: MOTION HOLDINGS, LLC, DELAWARE Free format text: CHANGE OF NAME;ASSIGNOR:COMAIR ROTRON, INC.;REEL/FRAME:036887/0929 Effective date: 20081014 |