EPA 608 Type 3 Practice Test: Chillers

Type III is for low-pressure equipment, which mostly means centrifugal chillers. Try three samples now.

What makes it "low-pressure"

A low-pressure appliance uses a refrigerant with a saturation pressure below 45 psia at 104 °F. EPA's examples are R-11, R-123, R-113 and R-245fa (40 CFR 82.152).

Much of a low-pressure system runs below atmospheric pressure. So leaks pull air and moisture in rather than letting refrigerant out. That one fact explains a lot of Type III.

The evacuation level changed

Current Table 1 uses one level for every low-pressure appliance: 25 mm Hg absolute, whatever the age of the recovery equipment (40 CFR 82.156(a)).

Older guides list 25 inches of Hg vacuum for older equipment and split chillers at 200 lb. Those rows are gone.

Opening a chiller for a quick repair

For a non-major repair that isn't followed by evacuation, a low-pressure appliance is brought up to 0 psig (atmospheric pressure) before opening. Openings are covered when the section can't be isolated (40 CFR 82.156(a)(1)(ii)).

The 85 °F rule matters here. If the refrigerant boils at or below 85 °F, as R-11 and R-123 do, you can't use methods such as nitrogen that would require purging the appliance.

Other Type III topics

• Purge units. They remove air and moisture from the condenser. Purging far more than usual points to a leak.
• Rupture discs. These protect the evaporator and vent outdoors.
• Recovery. Remove the liquid first, then the vapor. Keep water flowing or drain the tubes so they don't freeze.
• Charging. Charge vapor first until the saturation temperature is above freezing, then liquid.
• Leak repair. R-11 and R-123 chillers of 50 lb or more fall under Section 608 (40 CFR 82.157). HFC chillers of 15 lb or more, such as R-245fa, fall under the AIM Act rule (40 CFR 84.106). This is a separate rule from Section 608 (40 CFR 84.106). You need it on the job, but testing programs may not test it yet. Our practice labels AIM-only questions and leaves them out of the timed mock.
• Safety. R-123's toxicity class, refrigerant sensors in equipment rooms, and vapors that collect low.

Who should take Type III

Take it if you work in commercial buildings, hospitals, campuses or plants with chillers. It also completes Universal, which many employers ask for.

Common questions

Do I need Core for Type III? Yes. Every certification type requires passing Core plus the type section, 25 questions each (Appendix D).

Can I get Type III on its own? Yes. Type III is its own certification for low-pressure appliances (40 CFR 82.161(a)(1)(iii)). Add Types I and II later for Universal.

Is Type III closed-book? Yes. Type III must be taken closed-book with a proctor (Appendix D).

How to practice

Pass the free Core test first. Then unlock the full Type III bank and the Universal mock exam with the $19 one-time Universal pass.

Sources

• 40 CFR 82.152, definition of low-pressure appliance: https://www.ecfr.gov/current/title-40/section-82.152 (checked 2026-10-20)
• 40 CFR 82.156(a), Table 1, non-major repairs and the 85 °F rule: https://www.ecfr.gov/current/title-40/section-82.156 (checked 2026-10-20)
• 40 CFR 82.157 and 40 CFR 84.106, leak repair: https://www.ecfr.gov/current/title-40/section-82.157 and https://www.ecfr.gov/current/title-40/section-84.106 (checked 2026-10-20)
• EPA, Section 608 Test Topics (Type 3): https://www.epa.gov/section608/section-608-technician-certification-test-topics (checked 2026-10-20)
• 40 CFR Part 82, Appendix D to Subpart F: https://www.ecfr.gov/current/title-40/appendix-Appendix%20D%20to%20Subpart%20F%20of%20Part%2082 (checked 2026-10-20)