10.4 - Core Memorization Sheet

Module: Universal Review and Mock Examinations
Purpose: One-page-target rapid review of the highest-priority Core facts before Universal mock examinations
Covers: Core material consolidated from Modules 1–6
Regulatory verification basis: Current project material verified through August 14, 2026
Use: Memorize the distinctions, rules, and safety principles below; return to the detailed module files when a condition or exception is unclear

1. Ozone and Environmental Effects

Ozone

O3 = ozone

• Stratospheric ozone: beneficial; absorbs much harmful ultraviolet radiation.
• Ground-level ozone: harmful air pollutant.
• Less stratospheric ozone means more harmful UVB can reach Earth’s surface.

Ozone-Depletion Sequence

CFC / HCFC released
→ transported to stratosphere
→ UV breaks molecule apart
→ chlorine released
→ catalytic ozone destruction
→ chlorine regenerated and can repeat the cycle

ODP and GWP

Do not confuse: Zero ODP does not mean zero GWP, zero flammability, zero toxicity, or automatic regulatory acceptability.

2. Refrigerant Families

Blend Reminder

• Zeotropic / near-azeotropic blends: may have temperature glide.
• When required to avoid fractionation, remove the blend from the source cylinder as liquid.
• For superheat with a zeotropic blend, use dew point.
• For subcooling with a zeotropic blend, use bubble point.

3. Clean Air Act and Montreal Protocol

Clean Air Act
→ U.S. federal law

Section 608
→ stationary refrigeration / air-conditioning refrigerant management
→ 40 CFR Part 82, Subpart F

Montreal Protocol
→ international agreement
→ controls ozone-depleting substances

High-Priority Distinction

PRODUCTION / IMPORT PHASEOUT
≠
AUTOMATIC BAN ON USING EXISTING EQUIPMENT

Recovered, recycled, or reclaimed refrigerant may continue to be used where permitted.

Section 608 Versus Section 609

Section 608
→ stationary appliances

Section 609
→ MVAC service for consideration

Universal Section 608 certification does not replace Section 609 certification for paid MVAC service.

4. Venting

Central Rule

DO NOT KNOWINGLY VENT COVERED REFRIGERANT
during maintenance, service, repair, or disposal

Permitted Release Categories

1. De minimis release during a good-faith recovery, recycling, or safe-disposal attempt.
2. Release during normal operation rather than service or disposal.
3. Release of an EPA-exempt substitute in the specified end use.

Nitrogen Trap

Nitrogen alone
→ may be released safely after pressure testing

Nitrogen + covered refrigerant
→ DO NOT intentionally vent the mixture

Exam trap: Zero ODP does not automatically mean venting is allowed.

5. Refrigerant Sales

Stationary Refrigerant

Section 608 certified technicians may purchase refrigerant within the current Section 608 sales-restriction framework.

Section 609

Section 609 certification provides purchase authority for refrigerants acceptable for MVAC use within its scope.

Section 609 credential
≠
authority to buy stationary-system refrigerant such as R-22

Small-Can MVAC Exception

An uncertified person may purchase a qualifying small can of non-exempt substitute refrigerant for DIY MVAC use when the container is:

• 2 lb or less.
• Equipped with a unique fitting.
• Equipped with a self-sealing valve.

This exception does not authorize paid MVAC service or intentional venting.

6. The Three Rs

Ownership Reminder

Same owner
→ recovered / recycled refrigerant may be reused where technically suitable

Different owner
→ used refrigerant generally must follow the reclamation pathway before transfer for use as refrigerant

7. Recovery Equipment

System-Dependent

Uses appliance compressor and/or refrigerant pressure

• Ordinary system-dependent equipment is not used on appliances with a full charge greater than 15 lb, except for the permanently attached pump-out-unit provision.

Self-Contained

Has its own means to draw refrigerant from the appliance

Recovery Equipment Date

November 15, 1993
→ recovery/recycling equipment date
→ NOT appliance manufacture date

Recovery-Speed Principles

Faster recovery generally comes from:

• Shorter hoses.
• Larger hose diameter.
• Removing restrictions.
• Recovering bulk liquid first where appropriate.
• Using useful high- and low-side access.
• Safely controlling appliance and recovery-cylinder temperatures.

8. Recovery Cylinders

RECOVERY CYLINDER
→ refillable
→ receives recovered refrigerant

DISPOSABLE CYLINDER
→ one-way container
→ DO NOT refill
→ DO NOT use for recovery

Fill Safety

• Do not overfill recovery cylinders.
• Project exam-preparation rule: 80% maximum fill concept.
• Use a scale.
• More restrictive manufacturer, refrigerant, or transportation limits control actual field filling.
• Keep different refrigerants in separate cylinders.
• Never heat a cylinder with an open flame.
• Secure cylinders during transportation and protect them from excessive heat.

Do not confuse: Type I 80% recovery and cylinder 80% fill are different concepts.

9. Evacuation and Dehydration

Recovery Versus Evacuation

RECOVERY
→ remove + capture refrigerant

EVACUATION / DEHYDRATION
→ remove air + moisture

A vacuum pump is not a substitute for a recovery machine.

Pressure Scales

0 psig
≈ atmospheric pressure
≠ perfect vacuum

psig
→ referenced to atmosphere

psia
→ referenced to perfect vacuum

For vacuum scales:

in. Hg vacuum
→ larger number = deeper vacuum

mm Hg absolute / microns
→ smaller number = deeper vacuum

Standing Vacuum

After evacuation, isolate the system and observe pressure behavior.

• Rapid rise can indicate a leak.
• Slower rise that tends to stabilize can indicate remaining moisture / outgassing.
• Exact acceptance criteria may be manufacturer- or procedure-specific.

Triple Evacuation

A dehydration method may use:

evacuate
→ break vacuum with dry nitrogen
→ evacuate again
→ repeat as required

Dry nitrogen helps sweep moisture; it does not replace the final evacuation.

10. Safety

PPE

Use appropriate:

• Safety glasses / goggles.
• Gloves suitable for refrigerant exposure.
• Protective clothing and footwear.
• Additional PPE required by the refrigerant, task, and workplace.

Liquid refrigerant can cause:

FROSTBITE / EYE INJURY

Asphyxiation

Many refrigerants can displace oxygen.

Refrigerant vapor may collect in low areas

Do not enter an unsafe atmosphere without proper hazard assessment and required respiratory / confined-space controls.

Nitrogen Pressure Testing

Use:

DRY NITROGEN
+
PRESSURE REGULATOR
+
DOWNSTREAM RELIEF PROTECTION

Never use:

OXYGEN
or
COMPRESSED AIR

for refrigerant-system pressure testing.

Fire and Decomposition

• Keep refrigerants away from open flames and hot surfaces.
• High temperatures can produce hazardous decomposition products.
• Refrigerant-air mixtures under pressure can create dangerous conditions.
• Flammable refrigerants require control of ignition sources and compatible service equipment.

Electrical Safety

Before service:

DE-ENERGIZE
→ LOCKOUT / TAGOUT where required
→ VERIFY safe condition

A compressor that is not running may still have energized components.

11. Core Numbers and Words to Know Cold

High-Risk Exam Words

NOT • EXCEPT • MINIMUM • MAXIMUM • FIRST • LAST
CURRENT • HISTORICAL • REQUIRED • PROHIBITED
ABSOLUTE • GAUGE • RECOVER • RECYCLE • RECLAIM

12. Core Final Memory Map

OZONE
→ stratosphere protects from UV
→ chlorine / bromine can catalytically destroy ozone

CFC / HCFC
→ chlorine
→ nonzero ODP

HFC / HFO
→ no chlorine
→ zero ODP

CLEAN AIR ACT §608
→ U.S. stationary refrigerant management

MONTREAL PROTOCOL
→ international ODS control

NO INTENTIONAL VENTING
→ recover refrigerant

RECOVER → REMOVE
RECYCLE → CLEAN
RECLAIM → VERIFY

SYSTEM-DEPENDENT
→ appliance-assisted
SELF-CONTAINED
→ own recovery means

RECOVERY CYLINDER
→ refillable
DISPOSABLE CYLINDER
→ never refill

RECOVERY
≠
EVACUATION

NITROGEN
→ regulator + relief protection
NO oxygen / compressed air

PPE + ventilation + electrical safety
→ ALWAYS

References

Project Source Sections

• Section 1.7 - Quick Reference
• Section 2.9 - Quick Reference
• Section 3.8 - Quick Reference
• Section 4.9 - Quick Reference
• Section 5.10 - Quick Reference
• Section 6.10 - Quick Reference
• Section 10.2 - High-Priority Numbers and Thresholds
• Section 10.3 - Commonly Confused Terms