Office Action Predictor
Last updated: April 16, 2026
Application No. 18/749,543

HIGH-EFFICIENCY COOLING SYSTEMS AND METHODS FOR A COMPUTER DATA CENTER

Non-Final OA §102§103§112
Filed
Jun 20, 2024
Examiner
BAUER, CASSEY D
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Klein, Bradley John
OA Round
1 (Non-Final)
74%
Grant Probability
Favorable
1-2
OA Rounds
3y 0m
To Grant
96%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allow Rate
657 granted / 885 resolved
+4.2% vs TC avg
Strong +22% interview lift
Without
With
+21.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
35 currently pending
Career history
920
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
48.9%
+8.9% vs TC avg
§102
24.7%
-15.3% vs TC avg
§112
22.8%
-17.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 885 resolved cases

Office Action

§102 §103 §112
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 . Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. With reference to claim 1, in line 6 the word “thereat” lacks antecedent basis. It is therefore unclear the structure “thereat” is referring to. For the purposes of examination, the examiner is going to treat the claim as if it read, “a refrigerant return line directing the refrigerant at a second pressure toward the refrigerant source for cooling and recirculating of the refrigerant at the refrigerant source, wherein the second pressure is lower than the first pressure”. With reference to claim 1, in line 8 the word “therethrough” lacks antecedent basis. It is therefore unclear the structure “therethrough” is referring to. For the purposes of examination, the examiner is going to treat the claim as if it read, “a first heat exchanger configured to use the refrigerant circulating through the first heat exchanger to cool air or liquid which passes through the first heat exchanger”. With reference to claim 5, in line 2 the word “therethrough” lacks antecedent basis. It is therefore unclear the structure “therethrough” is referring to. For the purposes of examination, the examiner is going to treat the claim as if it read, “further comprising a second heat exchanger configured to use the refrigerant circulatingthrough the second heat exchanger to cool air or liquid which passes through the second heat exchanger”. With reference to claim 7, in line 1 the “first outlet temperature sensor” lacks antecedent basis. For the purposes of examination, the examiner is going to treat the claim as if it depended from claim 3 which does provide antecedent basis for a first outlet temperature sensor. With reference to claim 11, in line 5 the word “therethrough” lacks antecedent basis. It is therefore unclear the structure “therethrough” is referring to. For the purposes of examination, the examiner is going to treat the claim as if it read, “wherein the first heat exchanger is configured to use the refrigerant circulating through the first heat exchanger”. With reference to claim 12, in line 5 the word “thereof” lacks antecedent basis. It is therefore unclear the structure “thereof” is referring to. For the purposes of examination, the examiner is going to treat the claim as if it read, “detecting a refrigerant temperature in the refrigerant return line and using said refrigerant temperature for adjusting the bypass flow of the refrigerant”. Claims 2-4, 6, 8-10, and 13-16 are also rejected by virtue of dependency. 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)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claims 1, 2, 4, 5, 8, and 11-13 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by CN111356338 to Chen, hereinafter referred to as Chen, (see English language translation provided herewith). In reference to claim 1, Chen discloses the claimed invention including: A cooling system for a facility employing equipment requiring active cooling, the cooling system comprising: a refrigerant supply line providing a refrigerant at a first pressure from a refrigerant source (4) and a refrigerant return line directing the refrigerant at a second pressure toward the refrigerant source for cooling and recirculating of the refrigerant at the refrigerant source, wherein the second pressure is lower than the first pressure (See annotated reference below for the examiner’s definition of the refrigerant return and supply lines. Note that a pressure sensor 24 measures a difference between these two lines and since flow is always from a higher pressure to a lower pressure, it can be inferred that the pressure in the return line is lower than the pressure in the supply line even though Chen is silent to specific pressures in the supply and return lines), a first heat exchanger (at 5) configured to use the refrigerant circulating through the first heat exchanger to cool air or liquid which passes through the first heat exchanger and is used for active cooling of the equipment in the facility (IT load), the first heat exchanger having a first refrigerant inlet (from the supply line) configured to receive at least some refrigerant from the refrigerant supply line, the first heat exchanger having a first refrigerant outlet (to the return line) operably connected to direct at least some refrigerant to the refrigerant return line, and a first bypass line equipped with an in-line adjustable first valve (10) operable, when at least partially open, to allow at least some refrigerant to flow from the refrigerant supply line toward and mix with the refrigerant of the refrigerant return line without flowing through the first heat exchanger, thereby reducing a temperature of the refrigerant in the refrigerant return line to or below a preset maximum refrigerant temperature prior to reaching the refrigerant source. It should be noted that the claim does not further specify, define, or limit what, if any, additional structure is required in order to " reducing a temperature of the refrigerant in the refrigerant return line to or below a preset maximum refrigerant temperature prior to reaching the refrigerant source" beyond that previously recited, of which Chen includes, as detailed above PNG media_image1.png 596 961 media_image1.png Greyscale In reference to claim 2, Chen discloses the claimed invention including: a return line temperature sensor (22) positioned in the refrigerant return line downstream of the first heat exchanger (5), wherein the return line temperature sensor is configured to measure refrigerant temperature in the refrigerant return line prior to reaching the refrigerant source (4). In reference to claim 4, Chen discloses the claimed invention including: the refrigerant passing through the first heat exchanger (5) is a water (see abstract). In reference to claim 5, Chen discloses the claimed invention including: a second heat exchanger (as seen in figure 1) configured to use the refrigerant circulating therethrough to cool air (see underlined portion of page 8 of the English language translation) or liquid which passes through the second heat exchanger and is also used for active cooling of the equipment of the facility, the second heat exchanger having a second refrigerant inlet configured to receive at least some refrigerant from the refrigerant supply line, the second heat exchanger having a second refrigerant outlet operably connected to direct at least some refrigerant to the refrigerant return line. In reference to claim 8, Chen discloses the claimed invention including: the facility is a computer data center (data center IT load) and the air or liquid passing through the first heat exchanger is used for active cooling of computer equipment of the data center, see underlined portion of page 8 of the English language translation. In reference to claim 11, Chen discloses the claimed invention including: A method for cooling a facility employing equipment requiring active cooling, the method comprising the following steps: a. directing a refrigerant from a refrigerant supply line (as defined in the annotated reference with respect to claim 1 supra) pressurized at a first pressure through a first heat exchanger (5), wherein the first heat exchanger is configured to use the refrigerant circulating therethrough to cool air or liquid which passes through the first heat exchanger and is used for active cooling of the equipment in the facility (see underlined portion of page 8 of the English language translation), b. directing the refrigerant to flow from the first heat exchanger to a refrigerant return line (as defined in the annotated reference with respect to claim 1 supra) at a second pressure, wherein the second pressure is lower than the first pressure (implied by the disclosed pressure differential), and C. directing sufficient bypass flow of the refrigerant from the refrigerant supply line directly to the refrigerant return line via a first bypass line (as defined supra) and without flowing through the first heat exchanger, thereby keeping a refrigerant temperature in the refrigerant return line at or below a preset maximum refrigerant temperature. It is noted that a whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited, see MPEP 2111.04. Since the limitation of keeping a refrigerant temperature in the refrigerant return line at or below a preset maximum refrigerant temperature simply expresses the intended result of the positively recited step of directing bypass flow and does not require any further steps to be performed, the recitation of keeping a refrigerant temperature in the refrigerant return line at or below a preset maximum refrigerant temperature is not given patentable weight. In reference to claim 12, Chen discloses the claimed invention including: a step of detecting a refrigerant temperature in the refrigerant return line (via 22) and using thereof for adjusting the bypass flow (via 10) of the refrigerant to be sufficient to not exceed the preset maximum refrigerant temperature in the refrigerant return line. Note that the recitation of the bypass flow to be sufficient to not exceed the preset maximum refrigerant temperature in the refrigerant return line simply expresses the intended result of the positively recited step of adjusting the bypass flow and does not require any further steps to be performed. Accordingly, the intended result of the refrigerant to be sufficient to not exceed the preset maximum refrigerant temperature in the refrigerant return line is not given patentable weight, see MPEP 2111.04. In reference to claim 13, Chen discloses the claimed invention including: the facility is a computer data center and the air or liquid passing through the first heat exchanger is used for active cooling of computer equipment of the data center, see underlined portion of page 8 of the English language translation. 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 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. Claims 3 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of CN 117651405 to Zhu, hereinafter referred to as Zhu, (see English language translation provided herewith). In reference to claim 3, Chen and Zhu disclose the claimed invention. Chen fails to disclose the first heat exchanger further comprises a first outlet temperature sensor positioned at or downstream the first refrigerant outlet, the first outlet temperature sensor is configured to measure refrigerant temperature after passing through the first heat exchanger. Zhu teaches that it is a known method in the art of data center cooling systems to provide a first heat exchanger (3) that comprises a first outlet temperature sensor (Ts,1, out) positioned at or downstream the first refrigerant outlet, the first outlet temperature sensor is configured to measure refrigerant temperature after passing through the first heat exchanger (3). Zhu teaches that this method obtains the optimal working frequency of the variable-frequency pump of each data centre by calculating and deducing, optimizes the flow rate of the cooling water, enables each data centre to obtain the cooling water of the optimal heat exchange quantity under different calorific values, ensures the stable working temperature of each data centre, and does not cause the waste of the power resource of the cooling system, see underlined portion of page 7 of the English language translation. This is strong evidence that modifying Chen as claimed would produce predictable results (i.e., ensure stable working temperature of each data center). Accordingly, it would have been obvious to a person having ordinary skill in the art at the time the invention was effectively filed, to modify Chen by Zhu such that, the first heat exchanger further comprises a first outlet temperature sensor positioned at or downstream the first refrigerant outlet, the first outlet temperature sensor is configured to measure refrigerant temperature after passing through the first heat exchanger, since all claimed elements were known in the art, and one having ordinary skill in the art could have modified the prior art as claimed by known methods with no changes in their respective functions and the combination would have yielded a predictable result of ensuring stable working temperature of each data center. In reference to claim 7, Chen and Zhu disclose the claimed invention. Zhu teaches the first outlet temperature sensor Ts, 1, out is positioned downstream the first refrigerant outlet of the first heat exchanger (3). Accordingly, when modifying Chen by Zhu as applied in claim 3 supra, the limitations of claim 7 would be met by the combination. Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Chen as modified. In reference to claim 6, Chen as modified discloses the claimed invention. Chen fails to disclose a second bypass line equipped with an in-line adjustable second valve operable, when at least partially open, to allow at least some refrigerant to flow from the refrigerant supply line toward and mix with the refrigerant of the refrigerant return line without flowing through the second heat exchanger. It is noted that including a second bypass line with a second valve would do nothing more than provide additional flow of refrigerant to the return line without passing through a heat exchanger. This would be predictable to one skilled in the art. Further, there is no evidence of record that providing a second bypass and adjustable valve would do anything new and unexpected Accordingly, it would have been obvious to a person having ordinary skill in the art at the time the invention was effectively filed, to modify Chen such that the system included a second bypass line equipped with an in-line adjustable second valve operable, when at least partially open, to allow at least some refrigerant to flow from the refrigerant supply line toward and mix with the refrigerant of the refrigerant return line without flowing through the second heat exchanger since it has been held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced, see MPEP 2144.04 (VI)(B). Claims 9 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US10,225,952 to Chainer et al. hereinafter referred to as Chainer. In reference to claim 9, Chen and Chainer disclose the claimed invention. Chen fails to disclose a supplemental heat exchanger positioned downstream of the first heat exchanger, the supplemental heat exchanger placed outside the facility. Chainer teaches that in the art of electronic equipment cooling, that it is a known method to provide a refrigerant loop (300) with a supplemental heat exchanger (301) positioned downstream of the first heat exchanger (303), the supplemental heat exchanger placed outside a facility (304). This is strong evidence that modifying Chen as claimed would produce predictable results (i.e., transfer waste heat to the outdoor environment). Accordingly, it would have been obvious to a person having ordinary skill in the art at the time the invention was effectively filed, to modify Chen by Chainer such that, a supplemental heat exchanger was positioned downstream of the first heat exchanger, the supplemental heat exchanger placed outside the facility, since all claimed elements were known in the art, and one having ordinary skill in the art could have modified the prior art as claimed by known methods with no changes in their respective functions and the combination would have yielded a predictable result of transfer waste heat to the outdoor environment. Claims 16 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US2023/0247795 to Khalili et al., hereinafter referred to as Khalili. In reference to claim 16, Chen and Khalili disclose the claimed invention. Chen fails to disclose a step of directing at least some refrigerant coming out of the first heat exchanger to flow through a second heat exchanger prior to directing thereof to the refrigerant return line. Khalili teaches that in the art of IT cooling systems, that it’s a known method to direct at least some refrigerant coming out of a first heat exchanger (54) to flow through a second heat exchanger (56) prior to directing thereof to the refrigerant return line (22). This is strong evidence that modifying Chen as claimed would produce predictable results (i.e., use residual cooling of the cooling loop to cool lower demand heat loads). Accordingly, it would have been obvious to a person having ordinary skill in the art at the time the invention was effectively filed, to modify Chen by Khalili such that, at least some refrigerant coming out of the first heat exchanger was directed to flow through a second heat exchanger prior to directing thereof to the refrigerant return line, since all claimed elements were known in the art, and one having ordinary skill in the art could have modified the prior art as claimed by known methods with no changes in their respective functions and the combination would have yielded a predictable result of using residual cooling of the cooling loop to cool lower demand heat loads. Allowable Subject Matter Claims 10, 14 and 15 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include 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 CASSEY D BAUER whose telephone number is (571)270-7113. The examiner can normally be reached Mon-Thurs: 10AM-8PM (ET). 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, Frantz Jules can be reached at 571-272-6681. 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. /CASSEY D BAUER/ Primary Examiner, Art Unit 3763 /FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763
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Prosecution Timeline

Jun 20, 2024
Application Filed
Jan 29, 2026
Non-Final Rejection — §102, §103, §112
Mar 03, 2026
Interview Requested
Mar 16, 2026
Examiner Interview Summary
Mar 16, 2026
Applicant Interview (Telephonic)
Mar 26, 2026
Response Filed

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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
74%
Grant Probability
96%
With Interview (+21.5%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 885 resolved cases by this examiner. Grant probability derived from career allow rate.

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