[Congressional Bills 119th Congress]
[From the U.S. Government Publishing Office]
[S. 3269 Introduced in Senate (IS)]
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119th CONGRESS
1st Session
S. 3269
To direct the Comptroller General of the United States to conduct a
technology assessment focused on liquid cooling systems for artificial
intelligence compute clusters and high-performance computing
facilities, and for other purposes.
_______________________________________________________________________
IN THE SENATE OF THE UNITED STATES
November 20, 2025
Mr. McCormick (for himself, Mr. Coons, Mr. Budd, and Mr. Schiff)
introduced the following bill; which was read twice and referred to the
Committee on Energy and Natural Resources
_______________________________________________________________________
A BILL
To direct the Comptroller General of the United States to conduct a
technology assessment focused on liquid cooling systems for artificial
intelligence compute clusters and high-performance computing
facilities, and for other purposes.
Be it enacted by the Senate and House of Representatives of the
United States of America in Congress assembled,
SECTION 1. SHORT TITLE AND PURPOSE.
This Act may be cited as the ``Liquid Cooling for AI Act of 2025''.
SEC. 2. LIQUID COOLING DEPLOYMENT AND SCALABILITY.
(a) Findings.--Congress finds that--
(1) the 2024 United States Data Center Energy Usage Report
published by Lawrence Berkeley National Laboratory--
(A) indicates that data centers accounted for 4.4
percent of total United States electricity consumption
in 2023, up from 1.9 percent in 2018; and
(B) projects that data centers could represent
between 6.7 percent and 12.8 percent of total
electricity consumption by 2028, due to the rapid
growth of AI, cloud computing, and other digital
technologies;
(2) traditional air-cooled systems are reaching limits to
effectively remove heat from AI chips and hardware, and liquid
cooling-enhanced thermal performance is increasingly becoming a
necessity for high-density AI servers and data centers due to
the growing power consumption and heat generation of AI
workloads;
(3) liquid cooling technologies, including direct-to-chip
liquid cooling and single-phase or 2-phase immersion cooling,
can improve thermal performance, enable higher densities, and
reduce cooling system load when properly engineered and
maintained;
(4) effective liquid cooling deployments require
interoperable components and engineered subsystems, including
coolant distribution units, secondary loops, manifolds, hoses,
quick-disconnects, valves, pumps, filters, leak detection and
containment, corrosion control, and appropriate instrumentation
and controls;
(5) interfaces for heat-reuse are integral to liquid
systems and can reduce thermal load on heat-rejection equipment
by transferring heat through plate heat exchangers or other
devices to beneficial secondary uses where technically
appropriate;
(6) Federal agencies, including the Department of Energy,
are considering the deployment of AI systems across Government-
owned facilities; and
(7) a comprehensive, independent assessment of emerging
data center architectures and cooling technologies is essential
to inform efficient and cost-effective deployment decisions
across the Federal Government.
(b) Definitions.--In this section:
(1) 2-phase.--The term ``2-phase'', with respect to a
cooling process, means a process that leverages the heat-
absorbing phase change from liquid to gas during the cooling
cycle.
(2) AI.--The term ``AI'' has the meaning given the term
``artificial intelligence'' in section 5002 of the National
Artificial Intelligence Initiative Act of 2020 (15 U.S.C.
9401).
(3) Appropriate congressional committees.--The term
``appropriate congressional committees'' means--
(A) the Committee on Energy and Natural Resources
of the Senate;
(B) the Committee on Science, Space, and Technology
of the House of Representatives; and
(C) the Committee on Energy and Commerce of the
House of Representatives.
(4) Direct-to-chip liquid cooling.--The term ``direct-to-
chip liquid cooling'' means a liquid cooling method that
involves circulating a coolant in direct contact with
applicable heat-generating components, such as processors and
memory modules, to efficiently absorb and transfer heat away
from those heat-generating components.
(5) Heat-reuse.--The term ``heat-reuse'' means the capture
and transfer of waste heat from liquid loops for beneficial
secondary use through appropriate interfaces and controls.
(6) Immersion cooling.--The term ``immersion cooling''
means a cooling technique that involves a dielectric fluid
(single-phase or 2-phase) coming into direct contact with
information technology components to capture and reject heat
from an entire information technology system instead of a
single component.
(7) Liquid cooling.--The term ``liquid cooling'' means
utilization of liquids to remove heat efficiently from
electronic components.
(8) National laboratory.--The term ``National Laboratory''
has the meaning given the term in section 2 of the Energy
Policy Act of 2005 (42 U.S.C. 15801).
(9) Single-phase.--The term ``single-phase'', with respect
to a cooling process, means a process in which the coolant
remains in the same liquid state throughout the entire cooling
cycle.
(c) GAO Review.--
(1) In general.--Not later than 30 days after the date of
enactment of this Act, the Comptroller General of the United
States shall initiate a review of--
(A) the research and development needs relating to
liquid cooling utilization by data centers; and
(B) the related market, technological, and
regulatory conditions affecting that utilization.
(2) Elements.--The review required under paragraph (1)
shall include the following:
(A) An evaluation of liquid cooling research and
development needs, and the costs and benefits for high-
performance computing.
(B) A description of avoided costs of energy,
including deferred and avoided new electric
transmission and infrastructure upgrades and associated
costs.
(C) A description of increased compute capacity
through the enabling of more use of energy for
computing workloads rather than cooling.
(D) A survey and analysis of existing research on
the positive and negative effects of liquid cooling on
computing performance, resiliency, and cybersecurity.
(E) An assessment of market trends and adoption
rates of liquid cooling in United States data centers
over the past 5 years and projections of future trends
to account for the rapidly evolving industry and
potential market outlook.
(F) A comparison of single-phase and 2-phase
direct-to-chip to single-phase and 2-phase immersion
cooling across density bands, including relating to
thermal performance, maintainability, interoperability,
safety, failure modes, and lifecycle cost.
(G) An evaluation of--
(i) coolant options, including water,
water-glycol, and engineered fluids;
(ii) materials compatibility;
(iii) corrosion control;
(iv) biogrowth mitigation;
(v) filtration;
(vi) de-aeration;
(vii) fluid monitoring and management;
(viii) single-phase and 2-phase engineered
fluids;
(ix) testing for total thermal performance;
(x) heat transfer capacity; and
(xi) energy efficiency.
(H) Development of reference architectures and
layouts for rack, row, and room-level liquid
distribution by density band and cooling approach.
(I) A survey of existing opportunities for reusing
waste heat produced by data centers.
(J) An evaluation of failure scenarios (such as
pump failures or fluid leaks) and mitigation
strategies, especially in shared colocation
environments.
(K) Recommendations of the Comptroller General of
the United States relating to--
(i) whether liquid cooling should be
considered as a primary cooling option over air
cooling due to the thermal conditions of
computing components in servers within data
centers;
(ii) the utilization and ongoing research
by the Federal Government of liquid cooling
technologies;
(iii) best practices and industry standards
for the design and operation of liquid cooling
technologies;
(iv) methods to enhance the security,
reliability, and resilience of computing
equipment and data centers; and
(v) methods to accelerate education on
operational best practices.
(3) Stakeholder input.--For purposes of recommending the
best practices and industry standards described in paragraph
(2)(K)(iii), the Comptroller General of the United States shall
consult with stakeholders from Federal, State, and local
governments, the private sector, academia, and National
Laboratories.
(4) Liquid cooling advisory organization.--
(A) In general.--The Secretary of Energy and the
Comptroller General of the United States shall
establish an advisory committee to consult and
coordinate with in the preparation of the review under
paragraph (2).
(B) Members.--The advisory committee established
under subparagraph (A) shall consist of--
(i) interested parties who--
(I) have expertise in liquid
cooling system applications in the
development, operation, and
functionality of AI factories or data
centers, information technology
equipment, or software; and
(II) may be members of liquid
cooling industry organizations; and
(ii) representatives of hardware
manufacturers, data center operators, fluid
producers, or AI factory development.
(C) Consultation.--The advisory committee
established under subparagraph (A) shall consult with
relevant stakeholders, including the Department of
Energy, the National Laboratories, and any college,
university, research institution, industry association,
company, or public interest group with applicable
expertise in any of the subject matters areas described
in subparagraph (C).
(D) Termination.--The advisory committee
established under subparagraph (A) shall terminate on
the date on which the Secretary of Energy submits a
report and any recommendations under subsection (e).
(d) Report.--Not later than 90 days after the date of enactment of
this Act, the Comptroller General of the United States shall submit to
the Secretary of Energy and the appropriate congressional committees a
report containing the results, findings, and any associated
recommendations of the review required under subsection (c).
(e) Department of Energy Review.--Not later than 180 days after
receiving the report from the Comptroller General of the United States
under subsection (d), the Secretary of Energy shall submit to the
appropriate congressional committees an assessment of the report and
any associated recommendations, including--
(1) relevant considerations for Congress regarding the
importance of liquid cooling for the United States to maintain
its global lead in AI technologies; and
(2) recommendations for research and development on liquid
cooling and heat-reuse.
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