EPA 608 Type I vs Type II vs Type III: Which One Do You Need?

The short answer

Everyone takes Core. Then you add the type that matches the equipment you work on, or all three for Universal. Each section is 25 questions and needs 70% (18 right) on its own.

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Type I: small appliances

The regulation defines a small appliance as a product that is fully manufactured, charged and hermetically sealed in a factory with 5 lbs of refrigerant or less. Both halves count: a unit charged in the field is not a small appliance, however little refrigerant it holds.

What that looks like on the job:

• Household and commercial refrigerators and freezers
• Window and portable room air conditioners, packaged terminal units (PTACs, PTHPs)
• Dehumidifiers, under-the-counter ice makers, vending machines, water coolers

What it is not: car air conditioning (MVAC) is covered by Section 609, not 608. MVAC-like systems, such as the AC on farm and construction equipment, aren't small appliances either; techs service them with a Type II or a Section 609 certification.

The numbers Type I asks about

With recovery equipment made after November 15, 1993, you must recover 90% of the charge if the appliance compressor runs, 80% if it doesn't, or pull the appliance down to a 4-inch mercury vacuum. Some certifying organizations offer the Type I test by mail; that version needs 84% (21 of 25), and a Core section passed by mail doesn't count toward Universal.

Who needs it: appliance repair techs, and anyone servicing vending, ice and beverage equipment.

Type II: high-pressure appliances

A high-pressure appliance uses a refrigerant whose liquid-phase saturation pressure is between 170 and 355 psia at 104°F: R-22, R-407A, R-407C, R-410A and R-502 are the regulation's own examples. Type II also covers very high-pressure appliances, above 355 psia at 104°F, such as low-temperature systems on R-13 or R-503. Small appliances and car AC are left out.

In practice, Type II is most of the trade: residential and commercial split systems, heat pumps, rooftop units, supermarket cases, walk-ins and process refrigeration. New equipment is moving to A2L refrigerants such as R-454B and R-32, which are mildly flammable and change how you handle ignition sources and ventilation.

What Type II tests

• Leak detection, and the leak repair rules for larger systems.
• Required evacuation levels, which depend on how much refrigerant the appliance holds and when the recovery equipment was made.
• Recovery technique: liquid first, then vapor, and how to speed it up.

Leak repair got an update in 2026. Since January 1, 2026, appliances with 15 lbs or more of an HFC refrigerant (or a substitute with a GWP above 53) must be repaired when their annual leak rate passes 20% for commercial refrigeration, 30% for industrial process refrigeration, and 10% for comfort cooling and other appliances. Residential and light commercial AC and heat pumps are exempt; the AIM Act leak repair guide has the details.

Who needs it: residential and commercial HVAC techs and refrigeration techs. If you only get one type, it's probably this one.

Type III: low-pressure appliances

A low-pressure appliance uses a refrigerant with a liquid-phase saturation pressure below 45 psia at 104°F: R-11, R-123, R-113 and R-245fa are the regulation's examples. In the field that means centrifugal chillers cooling hospitals, campuses and office towers. Many new chillers use R-1233zd(E) in place of R-123.

What makes them different is that the low side runs below atmospheric pressure. A leak doesn't push refrigerant out; it pulls air and moisture in. That's why Type III questions keep coming back to:

• The purge unit, which removes air and other non-condensables. A purge unit that runs all the time is telling you there's a leak.
• The rupture disc on the evaporator, which bursts at 15 psig and is piped outdoors. Leak testing raises pressure gently, with warm water through the tubes, never past 10 psig.
• Recovery: liquid first, then vapor, with the water pumps running so the tube water doesn't freeze and split the tubes. The required evacuation level is 25 mm Hg absolute.

Who needs it: chiller techs and building engineers on large commercial plants.

Should you just go Universal?

If you don't know yet what equipment you'll be sent to, yes. Universal means passing Core plus all three types, it never expires, and it keeps every door open, from a window unit to a 500-ton chiller. You can take all four sections in one sitting or add types later.

Not sure you're ready for all four? Start with the Core exam guide, then try 10 free Core questions.

How to study the differences

1. Learn the definitions: 5 lbs and factory-sealed for Type I, the psia limits for II and III.
2. Pair each type with its numbers: Type I recovery percentages, Type III's 15 psig rupture disc and 25 mm Hg.
3. Drill each section in 25-question blocks, then take a full mock exam on the clock.

The EPA 608 Exam Prep app covers Core, Type I, Type II and Type III, with a timed Mock Exam that grades each section at 70% the way the real test does. It works offline, and Pro is a one-time purchase.