EPA 608 Certification Study Guide (Core + Type I/II/III)

1) What You Need to Know

EPA Section 608 (Clean Air Act) regulates how you handle refrigerants to prevent atmospheric release (ozone depletion + climate impact). The exam tests whether you can:

• Identify appliance categories (Type I, II, III) and what rules apply
• Follow recovery/evacuation requirements (the most testable numbers)
• Know venting prohibitions, leak repair rules, and proper service practices
• Use correct cylinders, recovery devices, and procedures

Big idea (the rule behind everything)

You may not knowingly vent refrigerant (including most substitutes) during service, maintenance, repair, or disposal. Use EPA-certified recovery equipment and follow required evacuation/recovery levels.

What each Type means (fast)

• Type I: Small appliances (factory-charged, hermetically sealed, typically $\le 5\,\text{lb}$ refrigerant)
• Type II: High-pressure + very-high-pressure appliances (most comfort cooling, refrigeration, heat pumps)
• Type III: Low-pressure appliances (centrifugal chillers using low-pressure refrigerants)
• Universal: Core + all Types

2) Step-by-Step Breakdown

A) Decide which certification/type rules apply

1. Is it a small appliance? (factory-charged + hermetically sealed + $\le 5\,\text{lb}$)
   • Yes \rightarrow Type I rules
2. If not small: Determine pressure category
   • Low-pressure \rightarrow Type III
   • High/very-high pressure \rightarrow Type II

On the test, “household refrigerator/window unit/water cooler/dehumidifier” usually screams Type I.

B) Recovery workflow (generic, exam-safe)

1. Verify recovery machine is EPA-certified and correct for refrigerant
2. Connect with low-loss fittings; minimize hose losses
3. Recover (liquid first when possible, then vapor)
4. Meet required evacuation/recovery level (Type-specific table below)
5. Isolate & monitor (watch for pressure rebound that indicates trapped refrigerant)
6. Close valves, shut off, and disconnect with minimal release
7. Label recovered refrigerant (never mix unknowns)

C) Type II (high-pressure) recovery: practical steps

1. Identify charge size: $<200\,\text{lb}$ vs $\ge 200\,\text{lb}$ (affects required vacuum)
2. Recover liquid first (faster, less wear)
   • Use push-pull only when conditions make sense (see traps)
3. Switch to vapor recovery to reach the target evacuation level
4. If system has failed compressor or restricted flow, slow down and prevent overheating

D) Type III (low-pressure chiller) recovery: practical steps

1. Get refrigerant out as a liquid when possible (low-pressure refrigerants often recover more efficiently as liquid)
2. Warm the evaporator/receiver (e.g., water flow/heat) to help boil off refrigerant
3. Use a recovery machine capable of handling low-pressure recovery and deep vacuum
4. Pull down to the required mm Hg absolute level
5. Watch for non-condensables (air) \rightarrow may require purging

Low-pressure chillers: the exam loves mm Hg absolute numbers and “air raises pressure” logic.

E) Type I (small appliance) recovery: practical steps

1. Confirm it’s truly small appliance (sealed + factory charge + $\le 5\,\text{lb}$)
2. Install access (process tube/piercing valve) using proper technique
3. Recover to the required percent recovery (depends on equipment date + whether compressor runs)
4. Properly cap/pinch off and prepare for disposal/recycling

3) Key Formulas, Rules & Facts

A) Refrigerant/environment basics (Core)

• ODS classes:
  • Class I: CFCs (higher ozone depletion)
  • Class II: HCFCs (lower ODP than CFCs, still regulated)
• ODP reference: CFC-$11$ defined as $\text{ODP}=1.0$
• GWP: climate impact relative to $CO_2$ (higher = worse warming effect)
• What destroys ozone: chlorine/bromine radicals released in the stratosphere under UV

B) “No venting” + allowed releases (Core)

• Prohibited: knowingly venting refrigerants (ODS and most substitutes)
• Allowed (de minimis) releases: small unavoidable releases when:
  • connecting/disconnecting hoses & gauges
  • leaks during normal operation (not intentional)

Intentionally “bleeding off” refrigerant to the air is not de minimis.

C) Recovery device definitions (Core)

D) Recovery / evacuation requirements (high-yield tables)

Type I: small appliance recovery levels (by percent)

Applies to factory-charged, hermetically sealed appliances with $\le 5\,\text{lb}$.

Type II: high-pressure & very-high-pressure evacuation levels

(Used for most split systems, rooftop units, supermarkets racks are typically high-pressure; very-high-pressure is rare but tested as a category.)

Type III: low-pressure evacuation levels

Watch the units: Type II uses psig and in Hg vacuum; Type III uses mm Hg absolute.

E) Leak repair rules (Core-heavy, often tested)

For appliances containing more than $50\,\text{lb}$ refrigerant (comfort cooling, commercial refrigeration, industrial process refrigeration):

General expectations:

• If leak rate exceeds the trigger, you must repair and verify within required timelines (exam commonly focuses on thresholds more than paperwork details).
• Chronic leak systems: you can’t keep “topping off” indefinitely.

F) Recovery cylinder rules (Core)

• Use DOT-approved recovery cylinders (commonly gray body/yellow top in practice, but color is not a reliable ID method)
• Do not fill above $80\%$ by volume (space for expansion)
• Store/transport cylinders properly; keep caps on

Max fill calculation (common test concept)

If cylinder water capacity is $WC$ (in $\text{lb}$ of water) and refrigerant liquid **specific gravity** is $SG$:

$W_{\max}=0.8\times WC\times SG$

G) Service practice essentials (Core)

• Never mix refrigerants in a cylinder (mixtures become expensive waste)
• Use low-loss fittings and minimize hose length
• Evacuation (deep vacuum) removes air/moisture; recovery is about removing refrigerant (don’t confuse them)
• Nitrogen is the standard for pressure testing/flowing while brazing (dry, inert)

Using oxygen for pressure testing is dangerous (fire/explosion risk).

4) Examples & Applications

Example 1: Identify the certification Type

Scenario: You’re servicing a household refrigerator that’s factory sealed.

• Key info: sealed + factory charge + typically $\le 5\,\text{lb}$
• Answer: Type I rules apply.

Example 2: Pick the correct Type II evacuation requirement

Scenario: A high-pressure rooftop unit has $250\,\text{lb}$ charge. Your recovery machine was manufactured after $11/15/1993$.

• Charge category: $\ge 200\,\text{lb}$
• Requirement: $10\,\text{in Hg vacuum}$.

Example 3: Low-pressure chiller evacuation target

Scenario: You’re recovering a low-pressure centrifugal chiller with recovery equipment manufactured after $11/15/1993$.

• Requirement: $25\,\text{mm Hg absolute}$.

Example 4: Leak repair threshold recognition

Scenario: A comfort cooling system with $80\,\text{lb}$ charge is leaking at an annualized rate of $12\%$.

• $80\,\text{lb}$ is **greater than** $50\,\text{lb}$ \rightarrow leak repair rules apply
• Comfort cooling threshold is $10\%$ \rightarrow $12\%$ exceeds it \rightarrow repair required.

5) Common Mistakes & Traps

1. Mixing up Type I vs “anything under $5\,\text{lb}$”
   Wrong: thinking any system with a small charge is Type I.
   Right: it must be factory-charged and hermetically sealed (small splits usually aren’t treated as “small appliances” on the exam).

2. Confusing vacuum units: “in Hg vacuum” vs “mm Hg absolute”
   Wrong: applying $10\,\text{in Hg vacuum}$ (Type II) to low-pressure chillers.
   Fix: memorize Type III = mm Hg absolute (either $25$ or $50\,\text{mm Hg absolute}$).

3. Forgetting the $11/15/1993$ equipment date split
   Wrong: using the same evacuation levels for all recovery machines.
   Fix: tie it to a phrase: “After $11/15/1993$ = deeper recovery required.”

4. Believing cylinder color tells you what refrigerant is inside
   Wrong: relying on “green for $R\text{-}22$” style rules.
   Fix: cylinder color conventions changed; labels and documentation matter.

5. Assuming ‘de minimis’ means you can vent a little on purpose
   Wrong: cracking a line to bleed refrigerant because “it’s just a small amount.”
   Fix: de minimis is unavoidable, not intentional.

6. Using push-pull in the wrong situation (Type II)
   Wrong: trying push-pull on small charges or when liquid isn’t available at the outlet.
   Fix: push-pull is best when you have a lot of liquid refrigerant and proper piping; otherwise it stalls and wastes time.

7. Topping off a known leaker (especially $>50\,\text{lb}$ systems)
   Wrong: repeatedly adding refrigerant without addressing leaks.
   Fix: know the $10\%$, $20\%$, $30\%$ leak thresholds and what they imply.

8. Not separating “recovered,” “recycled,” and “reclaimed”
   Wrong: thinking any cleaned refrigerant can be sold.
   Fix: selling used refrigerant typically requires reclamation to AHRI 700.

6) Memory Aids & Quick Tricks

7) Quick Review Checklist

• You can classify the appliance correctly: Type I vs II vs III.
• You know the key date $11/15/1993$ and how it changes recovery requirements.
• You can recall evacuation targets:
  • Type I: $70\%$/$80\%$/$90\%$ (by scenario)
  • Type II: $0\,\text{psig}$ or $10\,\text{in Hg vacuum}$ (older large systems: $4\,\text{in Hg vacuum}$)
  • Type III: $25\,\text{mm Hg absolute}$ or $50\,\text{mm Hg absolute}$
• You remember leak thresholds for $>50\,\text{lb}$: $10\%$ / $20\%$ / $30\%$.
• You can explain recovery vs recycling vs reclamation (AHRI $700$ for reclaim).
• You won’t fall for traps: “a little venting is ok,” “cylinder color proves refrigerant,” “any $<5\,\text{lb}$ system is Type I.”

You’ve got this: if you can nail the tables + definitions + leak thresholds, you’ll crush most EPA $608$ questions.