Prosecution Insights
Last updated: April 19, 2026
Application No. 18/237,827

MULTI-CIRCUIT HVAC SYSTEMS AND METHODS

Non-Final OA §102§103
Filed
Aug 24, 2023
Examiner
BABAA, NAEL N
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Johnson Controls Tyco Ip Holdings LLP
OA Round
1 (Non-Final)
77%
Grant Probability
Favorable
1-2
OA Rounds
2y 10m
To Grant
81%
With Interview

Examiner Intelligence

Grants 77% — above average
77%
Career Allow Rate
410 granted / 534 resolved
+6.8% vs TC avg
Minimal +4% lift
Without
With
+4.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
25 currently pending
Career history
559
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
49.8%
+9.8% vs TC avg
§102
17.4%
-22.6% vs TC avg
§112
31.0%
-9.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 534 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 Species E (Fig. 13) in the reply filed on 9/18/2025 is acknowledged. Claim Rejections - 35 USC § 102 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, 7-8, 17-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kester (US 2019/0170405). Regarding claim 1, Kester teaches a heating, ventilation, and air conditioning (HVAC) system (see Title), comprising: a primary heat transfer circuit (122, Fig. 6, paragraph [0035]), comprising: a first heat exchanger fluidly coupled to an ambient environment (60, Fig. 6, paragraph [0037]); an intermediate heat exchanger fluidly coupled to the first heat exchanger (126, Fig. 6, paragraph [0036]); and a compressor configured to circulate a refrigerant through the primary heat transfer circuit (68, Fig. 6, paragraph [0037]); a secondary heat transfer circuit (124, Fig. 6, paragraph [0035]), comprising: a second heat exchanger fluidly coupled to a thermal load (62, Fig. 6, paragraph [0038]); the intermediate heat exchanger, wherein the intermediate heat exchanger is fluidly coupled to the second heat exchanger (see Fig. 6); and a pump configured to circulate a heat transfer fluid through the secondary heat transfer circuit (70, Fig. 6, paragraph [0038]); a sensor configured to provide feedback indicative of an operational parameter of the heat transfer fluid (178, Fig. 6, paragraph [0045]); and a controller communicatively coupled to the compressor and the pump (176, Fig. 6, paragraph [0046]), wherein the controller is configured to receive the feedback and adjust operation of the compressor, the pump, or both, based on the feedback (see paragraph [0046]). Regarding claim 7, Kester teaches the HVAC system of claim 1, wherein the controller is configured to: determine, based on the feedback, a pressure of the heat transfer fluid; compare the pressure to a target operating pressure range of the heat transfer fluid; and execute a remedial operation in response to a determination that the pressure deviates from the target operating pressure range by a threshold amount (see paragraphs [0044]-[0046]). Regarding claim 8, Kester teaches the HVAC system of claim 1, wherein the heat transfer fluid comprises a non-volatile or inert fluid (see claim 3). Regarding claim 17, Kester teaches a heating, ventilation, and air conditioning (HVAC) system (see Title), comprising: a primary heat transfer circuit (122, Fig. 6, paragraph [0035]), comprising: a first heat exchanger fluidly coupled to an ambient environment (122, Fig. 6, paragraph [0035]); and a compressor fluidly coupled to the first heat exchanger and configured to circulate a refrigerant through the primary heat transfer circuit (68, Fig. 6, paragraph [0037]); a secondary heat transfer circuit (124, Fig. 6, paragraph [0035]), comprising: a second heat exchanger fluidly coupled to a thermal load (62, Fig. 6, paragraph [0038]); and a pump fluidly coupled to the second heat exchanger and configured to circulate a heat transfer fluid through the secondary heat transfer circuit (70, Fig. 6, paragraph [0038]), wherein the heat transfer fluid is a non-volatile or inert fluid (see claim 3); an intermediate heat exchanger disposed along the primary heat transfer circuit and the secondary heat transfer circuit (126, Fig. 6, paragraph [0036]), wherein the intermediate heat exchanger is configured to transfer heat between the refrigerant and the heat transfer fluid (see Fig. 6), wherein the primary heat transfer circuit is entirely external to a perimeter of the thermal load (see at least Fig. 5). Regarding claim 18, Kester teaches the HVAC system of claim 17, comprising a sensor configured to detect an operating parameter of the heat transfer fluid, wherein the controller is configured to receive feedback indicative of the operating parameter from the sensor and to adjust operation of the compressor, the pump, or both, based on the feedback (178, Fig. 6, paragraph [0045]). Regarding claim 19, Kester teaches the HVAC system of claim 18, wherein the operating parameter is a pressure of the heat transfer fluid, and the controller is configured to: compare the pressure to a target pressure range for the heat transfer fluid; and suspend operation of the compressor, the pump, or both, in response to a determination that the pressure is below the target pressure range (see paragraphs [0044]-[0046]). Regarding claim 20, Kester teaches the HVAC system of claim 17, comprising a sensor configured to detect a pressure of the refrigerant, wherein the controller is configured to: receive feedback indicative of the pressure from the sensor; compare the pressure to a target pressure range for the refrigerant; and suspend operation of the compressor, the pump, or both, in response to a determination that the pressure is below the target pressure range (see paragraphs [0044]-[0046]). Claim Rejections - 35 USC § 103 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. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. 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 2 is rejected under 35 U.S.C. 103 as being unpatentable over Kester in view of Hashimoto (US 2021/0095884). Regarding claim 2, Kester teaches the HVAC system of claim 1, but does not teach that the controller is configured to: determine, based on the feedback, a temperature of the heat transfer fluid; compare the temperature to a lower operating temperature threshold for the heat transfer fluid; and execute a remedial operation in response to a determination that the temperature is less than the lower operating temperature threshold. Hashimoto teaches an air conditioning system (Hashimoto, Title) which features a heat source unit (Hashimoto, 2, Fig. 2, paragraph [0053]) that is connected to a plurality of indoor units (Hashimoto, 1, Fig. 2, paragraph [0054]) through a heat exchanger (Hashimoto, 4, Fig. 2, paragraph [0019]), wherein the plurality of indoor units circulate heat medium (Hashimoto, paragraph [0022]) and when the temperature of the heat medium is less than a threshold, the controller performs steps to increase the temperature (Hashimoto, paragraph [0053]). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester with the controller determining the temperature of the heat transfer fluid and comparing it to a threshold and execute an operation in response to determining that the temperature is less than the threshold, as taught by Hashimoto, in order to maintain the desired temperature in the system. Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Kester in view of Hashimoto, as applied to claim 2, further in view of FOR1 (CN112484227A). Regarding claim 3, Kester as modified teaches the HVAC system of claim 2, but does not teach that the controller is configured to execute a temperature-increase control scheme as the remedial operation, and wherein, to execute the temperature-increase control scheme, the controller is configured to: decrease an operational speed of the compressor; increase an operational speed of the pump; or both. FOR1 teaches an air conditioner (FOR1, Title) which features a circulating system that is connected to an energy storage device which exchanges heat with the circulating system through energy storage material (FOR1, Abstract) wherein when it is determined that the temperature of the energy storage medium is lower than a preset temperature, the compressor frequency is reduced (FOR1, see Description). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester with reducing the compressor speed in the temperature increase control scheme, as taught by FOR1, in order to maintain the desired temperature in the system. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Kester in view of Hashimoto, as applied to claim 2, further in view of FOR2 (ES2219316T3). Regarding claim 4, Kester as modified teaches the HVAC system of claim 2, but does not teach that the controller is configured to deactivate the compressor, the pump, or both, in response to a determination that the temperature of the heat transfer fluid is below an additional lower operating temperature threshold that is less than the lower operating temperature threshold. FOR2 teaches a refrigerator (FOR2, Title) wherein when the temperature falls below a low temperature threshold, the compressor is deactivated (FOR2, Abstract at least, the Examiner notes that the general teaching of deactivating the compressor when the temperature falls below a threshold reads on both recited thresholds of the claim). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester as modified with deactivating the compressor when the temperature falls below the threshold, as taught by FOR2, in order to prevent damage to the system. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Kester in view of Hashimoto, as applied to claim 2, further in view of FOR3 (WO2015/140883A1). Regarding claim 5, Kester as modified teaches the HVAC system of claim 2, but does not teach that the controller is configured to: determine, based on additional feedback from an additional sensor, a composition of the heat transfer fluid; and determine, based on the composition, the lower operating temperature threshold. FOR3 teaches determining a threshold temperature value on the basis of the refrigerant composition which is acquired by a composition acquisition means (FOR2, see at least Abstract). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester as modified with determining the lower temperature threshold based on composition which is determined from a sensor, as taught by FOR3, in order to maintain the desired temperature as refrigerant fluctuates state in the operation of the HVAC system. Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Kester in view of Hashimoto, as applied to claim 2, further in view of FOR4 (EP2963359A1) and FOR5 (WO2022247797A1). Regarding claim 6, Kester teaches the HVAC system of claim 1, but does not teach the controller is configured to: detect, based on the feedback, an amount of the refrigerant mixed in the heat transfer fluid; and in response to detection of the amount, deactivate the compressor, the pump, or both. FOR4 teaches an air conditioning device (FOR4, Title) which detects whether there is a leak of primary loop refrigerant into the secondary loop in the intermediate heat exchanger (FOR4, see Description, see claims). FOR5 teaches that when a leak is detected, the compressor is immediately shut down. Therefore, it would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester as modified with an amount of refrigerant mixed with the heat transfer fluid in the intermediate heat exchanger and deactivating the compressor, as taught by FOR4 and FOR5, in order to protect the compressor and other equipment (FOR5, see Description). Claims 9-11 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Kester (US 2019/0170405) in view of Okazaki (US 2014/0196483), further in view of Cao (US 2021/0164700). Regarding claim 9, Kester teaches a heating, ventilation, and air conditioning (HVAC) system (see Title), comprising: a first primary heat transfer circuit (122, Fig. 6, paragraph [0035]), comprising a first heat exchanger fluidly coupled to an ambient environment (60, Fig. 6, paragraph [0037]), an intermediate heat exchanger fluidly coupled to the first heat exchanger (126, Fig. 6, paragraph [0036]), and a first compressor configured to circulate a first refrigerant through the first heat exchanger and the intermediate heat exchanger (68, Fig. 6, paragraph [0037]); a secondary heat transfer circuit (124, Fig. 6, paragraph [0035]), comprising a third heat exchanger fluidly coupled to a thermal load (62, Fig. 6, paragraph [0038]), the intermediate heat exchanger (see Fig. 6), and a pump (70, Fig. 6, paragraph [0038]), wherein the intermediate heat exchanger is fluidly coupled to the third heat exchanger (see Fig. 6), and the pump is configured to circulate a heat transfer fluid through the third heat exchanger and the intermediate heat exchanger (see Fig. 6); and a controller communicatively coupled to the first compressor (176, Fig. 6, paragraph [0046]). Kester does not teach a second primary heat transfer circuit, comprising a second heat exchanger fluidly coupled to the ambient environment, the intermediate heat exchanger, and a second compressor, wherein the intermediate heat exchanger is fluidly coupled to the second heat exchanger, and the second compressor is configured to circulate a second refrigerant through the second heat exchanger and the intermediate heat exchanger; and that the controller is coupled to the first and the second compressor, wherein the controller is configured to operate the first compressor and block operation of the second compressor in a first operating mode of the HVAC system and to operate the second compressor and to block operation of the first compressor in a second operating mode of the HVAC system. Okazaki teaches a heat pump (see Okazaki, Title) which features a primary circuit with a heat exchanger connected to an ambient environment (see Okazaki, 3a, Fig. 5, paragraph [0036]), a first compressor (see Okazaki, 1a, Fig. 5, paragraph [0036]) that is connected to a secondary circuit through an intermediate heat exchanger (see Okazaki, 5, Fig. 5, paragraph [0036]) and a second primary heat transfer circuit, comprising a second heat exchanger fluidly coupled to the ambient environment (see Okazaki, 3b, Fig. 5, paragraph [0036]), the intermediate heat exchanger (see Okazaki, 5, Fig. 5, paragraph [0036]), and a second compressor (see Okazaki, 1b, Fig. 5, paragraph [0036]), wherein the intermediate heat exchanger is fluidly coupled to the second heat exchanger (see Okazaki, Fig. 5), and the second compressor is configured to circulate a second refrigerant through the second heat exchanger and the intermediate heat exchanger (see Okazaki, Fig. 5). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester with a second primary circuit with the elements therein, as taught by Okazaki, in order to increase the overall rate of heat transfer in the system. Kester as modified does not teach that the controller is configured to operate the first compressor and block operation of the second compressor in a first operating mode of the HVAC system and to operate the second compressor and to block operation of the first compressor in a second operating mode of the HVAC system. Cao teaches a control method for a heat pump system (Cao, Title) with a first and second compressor (Cao, 1, 6, Fig. 2) wherein depending on the operating mode, the controller can turn on the main compressor and turn off the auxiliary compressor (Cao, paragraph [0054]). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester with blocking operation of the second compressor in a first operating mode of the HVAC system and to operate the second compressor and to block operation of the first compressor in a second operating mode of the HVAC system, as taught by Cao, in order to control the use of the system as desired. Regarding claim 10, Kester as modified teaches the HVAC system of claim 9, wherein the first refrigerant and the second refrigerant are different types of refrigerant (Kester, claim 12). Regarding claim 11, Kester as modified teaches the HVAC system of claim 9, wherein the first operating mode is a cooling mode, and the second operating mode is a heating mode (through the combination with Cao, the manipulation of each compressor is taught by the art and is capable of being applied to any desired operational mode switch). Regarding claim 14, Kester as modified teaches the HVAC system of claim 9, wherein the heat transfer fluid comprises a non-volatile or inert fluid (Kester, see claim 3). Claims 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Kester in view of Okazaki and Cao, further in view of FOR1 (CN112484227A). Regarding claim 15, Kester as modified teaches the HVAC system of claim 9, but does not teach a sensor configured to detect an operating parameter of the heat transfer fluid, wherein the controller is configured to receive feedback indicative of the operating parameter from the sensor and to adjust operation of the first compressor, the second compressor, the pump, or any combination thereof, based on the feedback. FOR1 teaches an air conditioner (FOR1, Title) which features a circulating system that is connected to an energy storage device which exchanges heat with the circulating system through energy storage material (FOR1, Abstract) wherein when it is determined that the temperature of the energy storage medium is lower than a preset temperature, the compressor frequency is reduced (FOR1, see Description). It would have been obvious to one of ordinary skill in the art, prior to the effective filing date, to provide Kester as modified with reducing the compressor speed in the temperature increase control scheme, as taught by FOR1, in order to maintain the desired temperature in the system. Regarding claim 16, Kester as modified teaches the HVAC system of claim 15, wherein the operating parameter is a temperature of the heat transfer fluid, and the controller is configured to: compare the temperature to a lower operating temperature threshold for the heat transfer fluid; and increase a first speed of the first compressor, increase a second speed of the second compressor, decrease a third speed of the pump, or any combination thereof, in response to a determination that the temperature is less than the lower operating temperature threshold (see FOR1, Abstract, Description at least, see motivation to combine in claim 15). Allowable Subject Matter Claims 12-13 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. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to NAEL N BABAA whose telephone number is (571)270-3272. The examiner can normally be reached M-F, 9-5 EST. 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, Jerry-Daryl Fletcher can be reached at (571)-270-5054. 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. /NAEL N BABAA/Primary Examiner, Art Unit 3763
Read full office action

Prosecution Timeline

Aug 24, 2023
Application Filed
Feb 06, 2026
Non-Final Rejection — §102, §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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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
77%
Grant Probability
81%
With Interview (+4.1%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 534 resolved cases by this examiner. Grant probability derived from career allow rate.

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