US20070125364A1

US20070125364A1 - Range Hood With Integrated CO Monitor

Info

Publication number: US20070125364A1
Application number: US11/564,647
Authority: US
Inventors: Andrew Crnkovich
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 2005-12-02
Filing date: 2006-11-29
Publication date: 2007-06-07
Also published as: WO2007064962A2; WO2007064962A3

Abstract

A range hood having a carbon monoxide sensor positioned therein is provided. The vent fan of the range hood is activated upon the detection of carbon monoxide so as to increase the ventilation of the cooking area. A visual and/or audible alarm may also be provided. If carbon monoxide levels increase or persist, the range hood may increase the speed of the vent fan to provide additional ventilation. Continued presence of carbon monoxide will result in the sounding of a warning. Interface to external warning devices and systems is also provided.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims the benefit of U.S. Provisional Patent Application No. 60/741,715, filed Dec. 2, 2005, the teachings and disclosure of which are hereby incorporated in their entireties by reference thereto.

FIELD OF THE INVENTION

This invention generally relates to consumer or commercial appliances, and more particularly to a range hood or over-the-range microwave oven.

BACKGROUND OF THE INVENTION

Accidental Carbon Monoxide (CO) poisoning is a growing issue. Every year hundreds of people are sickened and several deaths occur due to Carbon Monoxide poisoning, principally from improperly vented or maintained appliances. Ten States now require the installation of CO alarms in residential new construction and several metropolitan areas, including Chicago and New York City, require CO alarms in all residential dwellings.
Holiday cooking has been identified as a common cause of non-lethal CO poisoning. This may be the result of extended cooking in poorly ventilated areas and/or with poorly maintained equipment. This results in elevated CO levels, causing residents to report flu-like symptoms (headaches, nausea, fatigue etc.) which are indicative of low level CO poisoning. Since holiday cooking often occurs over several hours, even very low levels of CO can result in these symptoms.
Previous systems for venting the CO that results from cooking do not adequately address the long term, low level exposure that can result in the low level CO poisoning. One such system is described in U.S. Pat. No. 6,920,874, to Siegel, entitled Intelligent Ventilating Safety Range Hood. This system is capable of sensing CO and turn on the range hood ventilating fan when CO is detected above a certain minimum level. However, if the initial fan speed does not eliminate the hazardous condition, and even if the CO levels rise but remain below 35 ppm, typically because the cooking activity continues to produce CO, the fan speed is not increased. Indeed, the system of Siegel '874 does not take into account to duration of the exposure whatsoever, and provides no alarm unless the CO level rises above 35 ppm. Indeed, even when the Siegel '874 system does provide an alarm, it is only a local alarm in the range hood, which could result in confusion in homes with CO detectors installed because these detectors may not sound at all. This may result in occupants thinking that the range hood or their CO detectors are malfunctioning and not take appropriate action. As a result, a person could continue to suffer from low level CO poisoning.
There exists, therefore, a need in the art for a range hood or over-the-range microwave oven that can detect the presence of carbon monoxide, dynamically exhaust it in order to avoid low level CO poisoning, and provide adequate alarming an notification of the hazardous condition.
Embodiments of the invention provide such an appliance. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

BRIEF SUMMARY OF THE INVENTION

In view of the above, an embodiment of the present invention provides a new and improved consumer or commercial appliance that overcomes one or more of the problems existing in the art. More particularly, the present invention provides a range hood or over-the-range microwave oven that can detect the presence of carbon monoxide and provide ventilation thereof.
In one embodiment of the present invention an Carbon Monoxide (CO) sensor is incorporated into a range hood or over-the-range microwave oven to monitor CO levels. If elevated CO levels are detected, the CO sensor will automatically activate the exhaust fan. If the hazardous condition does not improve, the speed of the exhaust fan will be increased in an effort to vent the CO. If the hazardous condition, including persistent low levels of CO, persists, the CO sensor transmits a CO alarm activate signal to the external CO detectors in the residence to cause them to sound their alarm. Additional information may also be sent over a gateway for a smart home system.
Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is an isometric illustration of a gas cooking range and ventilation hood constructed in accordance with the teachings of the present invention.
While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a typical consumer dwelling 10 having kitchen with a range (or cook top) 12. A range hood (or over-the-range microwave oven, etc.) 14 is positioned over the range 12 to provide ventilation thereof. This ventilation may preferably be to the exterior of the dwelling 10.
A CO sensor 16 is incorporated into range hood 14 and continuously monitors the level of CO in the cooking area. In one embodiment, the CO sensor 16 includes an electrochemical CO sensor and controller circuitry. According to the Consumer Products Safety Commission (CPSC), the health effects of CO depend on the level of CO and length of exposure, as well as each individual's health condition. The concentration of CO is measured in parts per million (ppm). Health effects from exposure to CO levels of approximately 1 to 70 ppm are uncertain, but most people will not experience any symptoms. Some heart patients might experience an increase in chest pain. As CO levels increase and remain above 70 ppm, symptoms may become more noticeable (headache, fatigue, nausea). As CO levels increase above 150 to 200 ppm, disorientation, unconsciousness, and death are possible.
In the event unusual or persistent levels of CO are detected that may indicate a problem condition, the vent fan in the range hood 14 is activated. The CO levels may be similar as those currently used to activate a CO alarm in standard CO detectors installed today (UL 2034), e.g. an inverse relationship between the level of CO concentration and the time duration of exposure. Alternatively, the threshold for activation of the fan may be lower than the levels that would trigger a CO detector to sound its alarm, e.g. less than 30 ppm. Indeed, embodiments of the present invention activate the fan based on the detection of CO or the detection of CO above a certain level, e.g. 2 ppm.
Additionally or alternatively, a visual indicator 18 (e.g. message on LED display) is enabled to alert the resident that the vent fan is operating to improve indoor air quality due to the detected CO condition. In one embodiment, if CO levels do not improve over time, the speed of the vent fan will be increased automatically. If CO levels do not improve with increased air circulation, one embodiment of the present invention provides an audible and visual CO warning, advising the resident to move to fresh air. Such increase in fan speed and sounding of the alarm will occur even if the CO level does not increase, but remains at a low level for an extended period of time. Indeed, in one embodiment, the fan speed will continue to increase to its maximum until the level of CO drops.
If the home is equipped with RF enabled CO alarms 20, a signal is sent from the range hood 14 causing the alarms 20 to activate if the level of CO does not improve. This, despite an increase in fan speed. The range hood 14 will also signal for an alarm if it senses CO levels and time duration that would require alarming under UL 2034. If the home is equipped with a smart or connected home system, such as the Samsung Homevita system, a text message alerting the homeowner to the condition may also be sent over the gateway.
The Range hood preferably would incorporate a long-life CO sensor 16, such as a sensor that utilizes the Invensys Monox™ self-test technology, and would preferably be field serviceable. In the event the sensor 16 is not functioning, a visual and/or audible signal would alert the homeowner to replace the sensor. The range hood would continue to function normally in this condition.
All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. An apparatus configured for installation over a cooking appliance, comprising:

a vent fan;

an exhaust in fluid communication with the vent fan whereby air drawn by the vent fan is exhausted through the exhaust; and

a carbon monoxide (CO) sensor positioned therein; and

wherein the CO sensor turns on the vent fan when the CO sensor detects a presence of CO; and

wherein the CO sensor increases a speed of the vent fan when a level of CO detected by the CO sensor remains above a predetermined safe level after a first predetermined period.

2. The apparatus of claim 1, wherein the CO sensor is positioned to sense air in proximity to the cooking appliance.

3. The apparatus of claim 1, wherein the CO sensor increases the speed of the fan at predetermined intervals is the level of CO does not drop below the predetermined safe level.

4. The apparatus of claim 1, wherein the CO sensor increases the speed of the fan continuously until a drop in the level of CO is detected.

5. The apparatus of claim 1, wherein the CO sensor generates an alarm when the level of CO detected by the CO sensor remains above the predetermined safe level after a second predetermined period.

6. The apparatus of claim 5, wherein the CO sensor transmits an alarm activation signal to an external CO detector to activate its alarm.

7. The apparatus of claim 5, wherein the CO sensor transmits a text message to a smart home gateway.

8. The apparatus of claim 1, further comprising a visual indicator, and wherein the CO sensor activates the visual indicator when the CO sensor detects a presence of CO.

9. The apparatus of claim 8, wherein the visual indicator is an light emitting diode (LED).

10. The apparatus of claim 1, further comprising an audible indicator, and wherein the CO sensor activates the audible indicator when the CO sensor detects a presence of CO.

11. The apparatus of claim 1, further comprising an audible indicator and a visual indicator, and wherein the CO sensor activates the audible indicator and the visual indicator when the CO sensor detects a presence of CO.

12. The apparatus of claim 1, wherein the CO sensor is a self-testing CO sensor.

13. The apparatus of claim 12, further comprising an audible alarm, and wherein the audible alarm is triggered when the self-testing CO sensor determines that it is not functioning properly.

14. The apparatus of claim 12, further comprising a visual alarm, and wherein the visual alarm is triggered when the self-testing CO sensor determines that it is not functioning properly.

15. The apparatus of claim 1, wherein the CO sensor turns on the vent fan when the CO sensor detects a level of CO above a predetermined threshold.

16. The apparatus of claim 1, wherein the CO sensor turns on the vent fan when the CO sensor detects a level of CO for a period of time.

17. The apparatus of claim 16, wherein the level of CO is inversely related to the period of time.

18. A method of increasing the safety of cooking with a gas cooking appliance, comprising the steps of:

monitoring for carbon monoxide (CO) in proximity to the gas cooking appliance;

energizing an exhaust fan located over the gas cooking appliance when the step of monitoring detects the presence of CO; and

increasing the speed of the exhaust fan when the step of monitoring continues to detect the presence of CO above a predetermined safe level after a period of time.

19. The method of claim 18, further comprising the step of providing an indication of the presence of CO when the step of monitoring detects the presence of CO.

20. The method of claim 19, wherein the step of providing an indication of the presence of CO comprises the step of transmitting a radio frequency alarm activation signal to an external CO detector to cause it to sound its alarm.