CT HVAC case studies
CT HVAC · Put your knowledge to work in context.
HVAC Excellence is the HVACR education-and-workforce arm of ESCO Group, based in Mt. Its stated mission is to develop standards and resources that strengthen the quality of education, training, credentialing, and workforce development across the HVACR and building-science industries. The CT HVAC case studies are 5 cases and about 4,068 words.
1High Superheat, Zero Subcooling on a Fixed-Orifice Split System
A technician is sent to a 3-ton R-410A residential split system with a fixed-orifice (piston) metering device. The filter is clean and the evaporator coil has been washed.
733 words, about 4 min2Control Transformer Overload on a Zoned Heat Pump
A 3-ton heat pump with electric auxiliary heat and a three-zone damper panel serves a two-story house. The technician finds the Y1 contactor chattering and the zone panel occasionally dropping out, especially when a second zone calls while the reversing valve is energized.
823 words, about 4 min3Excessive External Static Pressure on a 3-Ton Retrofit
A 3-ton (1,200 CFM nominal) upflow furnace and coil in a 12-year-old house has complaints of long runtimes, warm bedrooms, and occasional frost on the suction line at the air handler. Measured at the tapped blower speed: return static −0.35 in.
773 words, about 4 min4Commissioning a New 2-Ton System at Low Ambient
A newly installed 2-ton R-410A split system with a TXV, matched coil, 3/8 in. liquid line, and a variable-speed air handler is ready for commissioning.
786 words, about 4 min5Spillage and Depressurization in a Natural-Draft Furnace Closet
A 100,000 BTU/h natural-draft furnace rated 80% AFUE sits in a closet measuring 4 ft × 2 ft × 8 ft (64 ft³) with a louvered door opening to a basement that was recently air-sealed. The homeowners added a 300 CFM bath fan and a 150 CFM dryer in the same basement.
953 words, about 5 min