Universal (Types I, II, and III)
What this domain covers
Universal certification is awarded after passing all three type exams, so the questions test your ability to attach the right rule to the right appliance class rather than to learn new subject matter. Expect mixed scenarios: a rooftop unit, a dehumidifier, and a chiller in the same question stem.
Rules you must be able to state
- Never vent any refrigerant, including HFCs and their substitutes. Recovery, recycling, or reclaim is required in every service situation.
- Know the three verbs. Recover means to remove refrigerant into an external container in any condition. Recycle means to clean it on site (oil separation, moisture and acid removal) for reuse in the same equipment. Reclaim means to reprocess it to new-product purity by an EPA-certified facility to AHRI 700 specifications.
- Sales restriction: technicians must be certified to purchase ozone-depleting refrigerants, and since January 1, 2018 the same restriction covers HFCs.
- Leak-rate thresholds apply to appliances holding 50 lb or more: 10% for comfort cooling, 20% for commercial refrigeration, 30% for industrial process refrigeration, 20% for other equipment, measured over 12 months. Exceeding the threshold requires repair within 30 days, followed by verification testing; records are kept three years. An appliance that leaks 125% of its charge in a year must be retrofitted or replaced.
- Cylinder and site safety: DOT-approved cylinders, filled by weight to no more than 80% of capacity, never flame-heated, always secured upright.
Traps that show up in questions
- Believing universal certification permits venting or exempts HFCs.
- Mixing evacuation targets: 80% charge for small appliances, 90%/80% or 10 in. Hg for high-pressure, 25 mm Hg absolute for low-pressure.
- Treating recycled refrigerant as if it were reclaimed; only reclaimed refrigerant may be sold or used in a different owner's equipment.
Rule of thumb
Before answering, name the appliance class out loud - that single identification usually eliminates three of the four answer choices.