Prosecution Insights
Last updated: April 18, 2026
Application No. 18/432,582

METHOD AND SYSTEM FOR GAS DETECTION

Non-Final OA §102§103
Filed
Feb 05, 2024
Examiner
ROYSTON, JOHN M
Art Unit
2855
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Carrier Corporation
OA Round
1 (Non-Final)
78%
Grant Probability
Favorable
1-2
OA Rounds
2y 7m
To Grant
95%
With Interview

Examiner Intelligence

Grants 78% — above average
78%
Career Allow Rate
497 granted / 639 resolved
+9.8% vs TC avg
Strong +17% interview lift
Without
With
+17.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
16 currently pending
Career history
655
Total Applications
across all art units

Statute-Specific Performance

§101
4.3%
-35.7% vs TC avg
§103
48.5%
+8.5% vs TC avg
§102
22.9%
-17.1% vs TC avg
§112
19.3%
-20.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 639 resolved cases

Office Action

§102 §103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Applicant’s election without traverse of invention I, claims 1-10 in the reply filed on 26 March 2026 is acknowledged. Claims 11-14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 26 March 2026. Claim Rejections - 35 USC § 102 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1 and 2 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Polk et al. US Pat 5,477,913 (hereafter Polk). As to claim 1: Polk discloses a multi gas detection system (see fig. 5 and col. 4, lines 62-67 and col. 5, lines 1-5) comprising one or more sensors (54; see fig. 5 and col. 5, lines 1-3) for detecting the presence of two or more of a refrigerant, a supply gas, and a combustion gas (see col. 3, lines 29-35). As to claim 2: Polk discloses the multi gas detection system of claim 1, wherein the multi gas detection system (see fig. 5) comprises a sensor component (54) and the sensor component consists of one sensor (see fig. 5; each sensor component 54 consists of a single sensor). Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Polk et al. US Pat 5,477,913 (hereafter Polk) in view of Rumler et al. US PG-PUB 2023/0058790 A1 (hereafter Rumler). As to claim 3: Polk teaches all of the limitations of the claimed invention as described above regarding claim 1, including one or more sensors (54) that can detect a refrigerant (see col. 3, lines 29-35), a supply gas (see col. 3, lines 29-35) and a combustion gas (see col. 3, lines 29-35), but does not explicitly teach: the one or more sensors detecting an A2L refrigerant. However, Rumler teaches that a sensor in an HVAC system may detect an A2L refrigerant (see ¶ 59). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Polk’s multi gas detection system such that the one or more sensors detect an A2L refrigerant because such refrigerants are commonly utilized as refrigerant in HVAC systems as suggested in ¶ 56 of Rumler and accordingly detection of the presence of such a refrigerant may be applied to detecting a refrigerant leak as also suggested in ¶ 56 and ¶ 59 of Rumler. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Polk et al. US Pat 5,477,913 (hereafter Polk) in view of McQuade et al. US PG-PUB 2019/0170598 A1 (hereafter McQuade). As to claim 5: Polk teaches all of the limitations of the claimed invention as described above regarding claim 1, including one or more sensors (54); but does not explicitly teach: wherein the one or more sensors comprise an infrared sensor, an electrochemical cell sensor, a metal oxide semiconductor sensor, a pellistor, a heated diode sensor, a molecular property sensor, or a combination thereof. However, McQuade teaches that one or more HVAC system sensors may comprise an infrared sensor (see McQuade ¶ 46). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Polk’s sensor to be an infrared sensor because such a sensor is an art recognized means of achieving the useful and predictable result of utilizing infrared light to detect combustion products and the concentration thereof, such as suggested in ¶ 46 of McQuade. Accordingly, such a construction could be utilized to modify the operation of the system in which the sensor is disposed if a potentially hazardous condition exists therein due to a high concentration of combustion gas, such as further suggested in ¶ 47 of McQuade. Claims 6, 7, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over McQuade et al. US PG-PUB 2019/0170598 A1 (hereafter McQuade) in view of Kurane et al. US PG-PUB 2023/0314041 A1 (hereafter Kurane) and Polk et al. US Pat 5,477,913 (hereafter Polk). As to claim 6: McQuade discloses an HVAC system (12; see fig. 2 and ¶ 23) comprising a fan (32; see fig. 2 and ¶ 26); a first heat exchanger (28; see fig. 2 and ¶ 25) located in an airflow created by the fan (see ¶ 26); and a second heat exchanger (30; see fig. 2 and ¶ 25). McQuade does not explicitly teach: the second heat exchanger being located in the airflow created by the fan and downstream of the first heat exchanger. However, Kurane teaches that a second heat exchanger may be located in an airflow created by a fan and downstream of a first heat exchanger (see ¶ 21). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify McQuade’s HVAC system such that a second heat exchanger is located in the airflow created by the fan and downstream of the first heat exchanger because multiple heat exchangers may lessen the burden of each individual exchanger when a flow is desired to be cooled while still allowing for a common discharge to be utilized, such as suggested in ¶ 21 of Kurane. McQuade also does not explicitly teach: multi gas detection system located between the first heat exchanger and the second heat exchanger wherein the multi gas detection system comprises one or more sensors for detecting the presence of two or more of a refrigerant, a supply gas, and a combustion gas. However, Polk teaches a multi gas detection system (see fig. 5 and col. 4, lines 62-67 and col. 5, lines 1-5) wherein the multi gas detection system comprises one or more sensors (54; see fig. 5 and col. 5, lines 1-3) for detecting the presence of two or more of a refrigerant, a supply gas, and a combustion gas (see col. 3, lines 29-35). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify McQuade’s system to include a multi gas detection system located between the first heat exchanger and the second heat exchanger wherein the multi gas detection system comprises one or more sensors for detecting the presence of two or more of a refrigerant, a supply gas, and a combustion gas because such a configuration is an art recognized means of achieving the useful and predictable result of both monitoring for the presence of multiple types of gas and also being able to determine which is present in a harmful level such that a fault condition can be utilized in order to prevent a hazardous condition, such as suggested in Polk col. 5, lines 11-20. As to claim 7: McQuade as modified by Kurane and Polk teaches the HVAC system of claim 6, wherein the multi gas detection system comprises a sensor component (54 of Polk) and the sensor component consists of one sensor (see Polk fig. 5; each sensor component 54 consists of a single sensor that may detect a different gas as disclosed in col. 5, lines 1-3). As to claim 10: McQuade as modified by Kurane and Polk teaches the HVAC system of claim 6, wherein the one or more sensors (54 of Polk) comprise an infrared sensor (see McQuade ¶ 46), an electrochemical cell sensor, a metal oxide semiconductor sensor, a pellistor, a heated diode sensor, a molecular property sensor, or a combination thereof. Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over McQuade et al. US PG-PUB 2019/0170598 A1 (hereafter McQuade) in view of Kurane et al. US PG-PUB 2023/0314041 A1 (hereafter Kurane) and Polk et al. US Pat 5,477,913 (hereafter Polk) as applied to claim 6 above, and further in view of Rumler et al. US PG-PUB 2023/0058790 A1 (hereafter Rumler). As to claim 8: McQuade as modified by Kurane and Polk teaches all of the limitations of the claimed invention as described above regarding claim 6, including one or more sensors (54 of Polk) that can detect a refrigerant (see Polk col. 3, lines 29-35), a supply gas (see Polk col. 3, lines 29-35) and a combustion gas (see Polk col. 3, lines 29-35), but does not explicitly teach: the one or more sensors detecting an A2L refrigerant. However, Rumler teaches that a sensor in an HVAC system may detect an A2L refrigerant (see ¶ 59). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to further modify McQuade’s system such that the one or more sensors detect an A2L refrigerant because such refrigerants are commonly utilized as refrigerant in HVAC systems as suggested in ¶ 56 of Rumler and accordingly detection of the presence of such a refrigerant may be applied to detecting a refrigerant leak as also suggested in ¶ 56 and ¶ 59 of Rumler. Allowable Subject Matter Claims 4 and 9 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: As to claim 4: The prior art of record does not disclose or render obvious to the skilled artisan an HVAC system wherein the one or more sensors has a threshold limit of greater than or equal to 25% of the lower flammability limit for a refrigerant and a threshold limit of 1000 ppm for a supply gas, or a combination thereof, when considered in combination with the limitations of parent claim 1. In particular, while Polk is considered to teach the features of claim 1 (see the above 35 U.S.C. 102(a)(1) rejection of claim 1) and it is known from the prior art to detect a flammable refrigerant (see, for example, De US PG-PUB 2023/0029164 A1 ¶ 64), there does not appear to be a disclosure therein or suggestion available in any of the cited prior art of record that renders obvious the one or more sensors having a threshold limit of greater than or equal to 25% of the lower flammability limit for a refrigerant and a threshold limit of 1000 ppm for a supply gas, or a combination thereof, such as required by the limitations of the instant claim. As to claim 9: The prior art of record does not disclose or render obvious to the skilled artisan an HVAC system wherein the one or more sensors has a threshold limit of greater than or equal to 25% of the lower flammability limit for a refrigerant and a threshold limit of 1000 ppm for a supply gas, or a combination thereof, when considered in combination with the limitations of parent claim 6. In particular, while McQuade, Kurane, and Polk are considered to teach the features of claim 6 (see the above 35 U.S.C. 103(a) rejection of claim 6) and it is known from the prior art to detect a flammable refrigerant (see, for example, De US PG-PUB 2023/0029164 A1 ¶ 64), there does not appear to be a disclosure therein or suggestion available in any of the cited prior art of record that renders obvious the one or more sensors having a threshold limit of greater than or equal to 25% of the lower flammability limit for a refrigerant and a threshold limit of 1000 ppm for a supply gas, or a combination thereof, such as required by the limitations of the instant claim. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN M ROYSTON whose telephone number is (571)270-7215. The examiner can normally be reached M-F 8-4:30 E.S.T.. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Peter Macchiarolo can be reached at 571-272-2375. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JOHN M ROYSTON/Examiner, Art Unit 2855
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Prosecution Timeline

Feb 05, 2024
Application Filed
Apr 04, 2026
Non-Final Rejection — §102, §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
78%
Grant Probability
95%
With Interview (+17.3%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 639 resolved cases by this examiner. Grant probability derived from career allow rate.

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