HVAC Excellence AC case studies
HVAC Excellence AC · Put your knowledge to work in context.
HVAC Excellence is the HVACR education and workforce standards program of ESCO Group / ESCO Institute, based in Mt. According to the program's own page, HVAC Excellence "develops standards and resources that strengthen the quality of education, training, credentialing, and workforce development across the HVACR and building science industries." It is not a single exam. The HVAC Excellence AC case studies are 5 cases and about 3,497 words.
1High Superheat With Normal Subcool on a Fixed-Orifice System
A residential service call involves a 3-ton R-410A split system with a fixed-orifice metering device and a PSC blower. The homeowner reports that the house has not cooled below 78°F since the filter was replaced.
675 words, about 3 min2Compressor Overload Trip on a Low-Charge Packaged Unit
A 5-ton R-410A packaged rooftop unit with a three-phase Copeland scroll compressor serves a small office. The unit cools for about eight minutes, then the compressor internal overload opens; the indoor fan continues to run.
709 words, about 4 min3TXV Starvation After a Liquid-Line Restriction
A 10-ton R-410A commercial split system with a TXV and a scroll compressor serves a conference room. The room is 78°F instead of 72°F, and the compressor runs continuously.
708 words, about 4 min4Economizer and Demand-Control Ventilation Fault in a Packaged Rooftop
A 20-ton R-410A packaged rooftop unit with two cooling stages, an economizer, and demand-control ventilation serves a 4,000 ft² office. Occupants complain of stale air and headaches in the afternoon.
673 words, about 3 min5Coaching a Student Through Refrigerant Charging in the Lab
An instructor supervises a lab practical in which a student is troubleshooting a 3-ton R-410A residential split system with a TXV. The outdoor ambient is 92°F, indoor return air is 76°F dry bulb and 64°F wet bulb.
732 words, about 4 min