AR HVAC case studies

AR HVAC · Put your knowledge to work in context.

The Arkansas HVAC-R licensing examination is the assessment tied to state licensure for work on heating, ventilation, air conditioning and refrigeration systems in Arkansas. It is intended for technicians and contractors who need to demonstrate trade competence before practicing, and it appears within the licensing structure of the Arkansas Department of Labor and Licensing. Preparation should be built around four broad content areas that mirror the trade itself: fundamentals, safety and tools; the refrigeration cycle, components and refrigerants; electrical systems and controls; and installation, service, load calculation and code or regulatory requirements. Because the exam blends hands-on trade knowledge with electrical theory and code, candidates generally do best with a staged study plan - theory first, then components and diagnostics, then code and installation practice - followed by timed practice questions in every domain. The AR HVAC case studies are 5 cases and about 3,814 words.

The Dental Office That Won't Cool: Airflow or Charge?

You are the second technician sent to a 1,800 sq ft dental office with a 3-ton R-410A packaged rooftop unit. Outdoor ambient is 96°F; return air at the unit is 78°F dry bulb and 63°F wet bulb.

700 words, about 4 min 2

High Superheat, Low Subcooling: Undercharge or Restriction?

A 3-ton R-410A split system with a thermostatic expansion valve serves a residence. Outdoor ambient is 85°F and indoor conditions are 75°F dry bulb / 63% relative humidity.

729 words, about 4 min 3

Contactor Pulls In, Compressor Hums and Trips

You are called to a 2.5-ton residential split with a reciprocating compressor and a single-pole contactor. The thermostat is calling for cooling.

771 words, about 4 min 4

The Upsize Request: 2.5 Tons to 3 Tons

A homeowner with a 1,800 sq ft single-story house built in 1978 asks you to replace a failed 20-year-old R-22, 2.5-ton condensing unit with a 3-ton R-410A unit because 'the old one never kept up in July.' The existing line set is 3/8 in. vapor, 35 ft long, with no oil trap.

807 words, about 4 min 5

Recovery, Line Set Reuse, and a Vacuum That Won't Hold

You are replacing a failed R-22 condensing unit with a new R-410A unit. The old system's nameplate charge is 6.5 lb of R-22.

807 words, about 4 min