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Air Force AFSC · Engineering

3E1X1 Heating, Ventilation, Air Conditioning and Refrigeration

Current service use not established

This code is listed in the directory. Inclusion alone does not confirm current service use.

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Overview

Heating, Ventilation, Air Conditioning and Refrigeration specialists maintain the mechanical systems that control temperatures in spaces across their bases. They install, maintain, and repair HVAC and refrigeration systems used in different climates around the world.

Minimum ASVAB: M 55 or E 45

ASVAB policy: Not policy-reviewed · coverage unknown · as of 2026-10-19

Program scope has not been reviewed.

Policy applicability and coverage of the program's score routes have not been reviewed. Shown-route arithmetic is not an eligibility decision.

Source: dafecd-atch4-2025-10-31 (source date 2025-10). Policy applicability has not been established.

See if you would hit this score: free ASVAB practice test

Skill levels: 3E111 helper · 3E131 apprentice · 3E151 journeyman · 3E171 craftsman

Core Skills

  • Combustion equipment operation and repair
  • Industrial air compressor maintenance and repair

Civilian Career Paths

Career associations are editorial assessments of the cited evidence, not an official crosswalk unless the evidence explicitly says so. O*NET supplies civilian occupation information, not proof of a military match. Related experience does not confer civilian qualifications. Tasks and tools below describe civilian work, not military training.

Heating, Air Conditioning, and Refrigeration Mechanics and Installers

Military experience installing, operating, maintaining, and repairing HVAC/R systems directly overlaps civilian heating, cooling, and refrigeration service work.

How to prepare: Practice using a civilian equipment manufacturer's installation specifications to map component placement and connections for a system you have serviced. EPA Section 608 certification is required for covered work on equipment that could release regulated refrigerants, subject to applicable exceptions such as closely supervised apprentices; state or local HVAC licensing requirements vary by jurisdiction and scope of work.

What the civilian work involves
  • Test electrical circuits or components for continuity, using electrical test equipment.
  • Study blueprints, design specifications, or manufacturers' recommendations to ascertain the configuration of heating or cooling equipment components and to ensure the proper installation of components.
  • Connect heating or air conditioning equipment to fuel, water, or refrigerant source to form complete circuit.

Training & Development

Choose credentials for your target role. COOL funding markers describe program listings, not a guarantee of eligibility or funding.

Career Growth

  • Certified Maintenance and Reliability Professionals (CMRP)

    Demonstrate broader maintenance and reliability knowledge when expanding beyond hands-on HVAC/R service responsibilities.

    Eligibility and preparation: No minimum education or work experience is required; candidates must not have sat for the exam within the preceding six months.

    For: Heating, Air Conditioning, and Refrigeration Mechanics and Installers

Notes & Sources

Evidence for this guidance (4 documents)
  1. DAFECD, 30 Apr 26: HEATING, VENTILATION, AIR CONDITIONING, AND REFRIGERATION (3E1X1)

    [1] Specialty Summary section "HEATING, VENTILATION, AIR CONDITIONING, AND REFRIGERATION"; normalized cached text lines 9306-9327; explicit AFSC match for 3E1X1

    Supports: Combustion equipment operation and repair, Industrial air compressor maintenance and repair, Heating, Air Conditioning, and Refrigeration Mechanics and Installers (O*NET 49-9021.00)

  2. O*NET: Heating, Air Conditioning, and Refrigeration Mechanics and Installers

    [2] O*NET 30.3 occupational data

    Supports: Heating, Air Conditioning, and Refrigeration Mechanics and Installers (O*NET 49-9021.00)

  3. COOL credential mapping: Certified Maintenance and Reliability Professionals (CMRP)

    [3] 3E1X1 cached COOL credential feed

    Supports: Certified Maintenance and Reliability Professionals (CMRP)

  4. Society for Maintenance and Reliability Professionals: CMRP eligibility

    [4] Eligibility; retrieved 23 September 2026

    Supports: Certified Maintenance and Reliability Professionals (CMRP)

Defense contractor jobs for 3E1X1

Predecessor codes

Historical codes with documented links to 3E1X1. Each history page explains the change.

54510Heating, Ventilation, Air Conditioning, and Refrigeration Helper54530Apprentice Heating, Ventilation, Air Conditioning, and Refrigeration Specialist54570Heating, Ventilation, Air Conditioning, and Refrigeration Technician54590Heating, Ventilation, Air Conditioning, and Refrigeration Superintendent

Descriptions may be summarized for clarity. Verify all information with your branch career counselor or official military documentation before making career decisions.

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