As defined in the Code of Federal Regulations (CFR), "direct expansion-dedicated outdoor air systems," or "DX-DOAS," means a unitary dedicated outdoor air system that is capable of dehumidifying air to a 55 °F dew point - when operating under Standard Rating Condition A as specified in Table 4 or Table 5 of AHRI 920-2020 with a barometric pressure of 29.92 in Hg - for any part of the range of airflow rates advertised in manufacturer materials, and has a moisture removal capacity of less than 324 lb./h. 10 CFR 431.92.
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For the latest information on the planned timing of future DOE regulatory milestones, see the current Office of Management and Budget Unified Agenda of Regulatory and Deregulatory Actions. All planned dates are preliminary and subject to change.
Standards
Final rule - Federal Register, 87FR65651 (November 1, 2022)
Notice of Proposed Rulemaking - Federal Register, 87FR5560 (February 1, 2022)
Notice of Data Availability - Federal Register, 84FR48006 (September 11, 2019)
- Frequently Asked Questions
- Technical Support Document
The direct expansion-dedicated outdoor air systems energy conservation standard rulemaking docket EERE-2017-BT-STD-0017contains all notices, public comments, public meeting transcripts, and supporting documents pertaining to this rulemaking.
Public Meeting Information
There is no public meeting scheduled at this time.
Submitting Public Comments
The comment period is closed.
Test Procedure
Final Rule - Federal Register, 87FR45164 (July 27, 2022)
Supplemental Notice of Proposed Rulemaking - Federal Register, 86FR72874 (December 23, 2021)
Notice of Proposed Rulemaking - Federal Register, 86FR36018 (July 7, 2021)
The direct expansion-dedicated outdoor air systems test procedure rulemaking docket EERE-2017-BT-TP-0018 contains all notices, public comments, public meeting transcripts, and supporting documents pertaining to this rulemaking.
Public Meeting Information
There is no public meeting scheduled at this time.
Submitting Public Comments
The comment period is closed.
Direct expansion-dedicated outdoor air systems manufactured and distributed in commerce, as defined by 42 U.S.C. 6291(16), must meet the energy conservation standards specified in the Code of Federal Regulations at 10 CFR 431.97(h).
Beginning July 24, 2023, representations with respect to energy use or efficiency of direct expansion-dedicated outdoor air systems must be based on testing conducted in accordance with Appendix B to Subpart F of Part 431.
Compliance
DOE has established regulations on certification, compliance, and enforcement in the CFR at 10 CFR Part 429. These regulations cover statistical sampling plans, certified ratings, certification reports, record retention, and enforcement. More information on these regulations is available here.
Waivers
For information on current test procedure wavers, see DOE’s Waivers webpage.
For information about obtaining test procedure waivers, see 10 CFR part 431, subpart V.
Exceptions
DOE's Office of Hearings and Appeals has not authorized exception relief for dedicated outdoor air systems.
For information about obtaining exception relief, see 10 CFR part 1003.
Guidance and Frequently Asked Questions
For information on further guidance and answers to frequently asked questions on all covered products, see DOE’s Further Guidance database.
State Exemptions to Federal Pre-emption
DOE has not exempted any state from this energy conservation standard. States may petition DOE to exempt a state regulation from preemption by the federal energy conservation standard. States may also petition DOE to withdraw such exemptions. For details, see 10 CFR part 431, subpart W.
For more information related to this product, please email:
ApplianceStandardsQuestions@ee.doe.gov