Question 1Substitutes, oils and blends
What is temperature glide in a zeotropic blend?
Get ready for your refrigerant certification test, one section at a time.
Find your weakest section in a free 15-minute diagnostic, fix it with a short lesson, and practice Core and every type with each answer explained.
The only interactive course with a tutor that finds your weak spots and fixes them.
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Free evacuation level lookup
Pick the refrigerant, the charge, the job and when the recovery machine was made, and get the level the rule requires, with the reason. The full page has the table and practice questions.
Find the required level
High-pressure (R-22)
10 inches of mercury vacuum
Before a major repair, a high-pressure appliance with a full charge of 200 pounds or more must reach 10 inches of mercury vacuum when the recovery equipment was made on or after 15 November 1993.
Verify the level is reached before the appliance is opened.
More free practice
- 15-question diagnosticAll four sections: your score in each, a lesson on the weakest, and a plan. No account.
- Core practice testA full 25-question Core section, the part every certification needs, scored against the 70 percent mark.
- A test for each type10 questions on Type I, Type II or Type III, with a lesson on what you missed.
- Leak-rate calculatorBoth methods the rule allows, the 20, 30 and 10 percent limits, and what happens over the limit.
The four sections
Each section is 25 questions and passes at 70 percent, 18 of 25. Core plus the types you need; Universal is all four.
Core
Ozone and the law, the Section 608 rules, substitutes and oils, the refrigeration cycle, recovery, dehydration, safety and shipping.
Every certification
Type I
What counts as a small appliance, how much to recover, passive and active recovery, access valves and safety.
Small appliances
Type II
Leak detection and the leak repair rules, evacuation levels by charge and equipment date, recovery technique and pressure-temperature.
High-pressure systems
Type III
Chillers below atmospheric pressure: purge units, hot-water pressurizing, 25 mm Hg absolute, recovery and charging vapor first.
Low-pressure systems
Try one question from each section
Question 2Small appliance recovery
Why does warming the compressor of a failed small appliance speed passive recovery?
Question 3Evacuation levels
A technician must replace the expansion valve on a 400 lb R-22 system with a 2015 recovery machine. The job is not major, and no evacuation is planned afterward. What level is required?
Question 4Recharging
Why is vapor charged before liquid into an evacuated low-pressure chiller?
In the course
- 19 interactive lessons
- 186 practice questions
- 2 full 100-question Universal practice exams
Guides
Refrigerant Genius Pro
US$24one payment
- 19 interactive lessons
- 186 practice questions
- 2 full 100-question Universal practice exams
Full refund within 14 days. Ask within 14 days of paying, for any reason. Our refund promise still applies after you start the course. The note under the pay button is about the separate legal right to cancel. Terms
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One payment. No sales tax is added. Access until October 31, 2027.
Questions? support@unigenius.co.uk