ID HVAC case studies
ID HVAC · Put your knowledge to work in context.
The Idaho HVAC Board is one of the occupational boards administered by the Idaho Division of Occupational and Professional Licenses (DOPL), the state agency whose stated mission is "Dedicated to Consumer Protection and Public Safety." DOPL's Building, Construction & Real Estate group lists the HVAC Board alongside Electrical, Plumbing, Factory Built Structures, and Liquefied Petroleum Gas Safety, and DOPL's online services include purchasing an Electrical, HVAC or Plumbing permit and requesting an Electrical, HVAC or Plumbing inspection. This page is an independent study resource for candidates preparing for the Idaho HVAC Board licensing examination; it is not affiliated with, endorsed by, or operated by DOPL or the HVAC Board. The ID HVAC case studies are 5 cases and about 4,357 words.
1Cold-Climate Heat Pump Retrofitted With a 30°F Compressor Lockout
A homeowner in a climate with a 99% heating design temperature of 8°F replaced a failing 3-ton R-22 air conditioner and 80% AFUE furnace with a cold-climate variable-speed heat pump rated 24,000 Btu/h at 47°F and 14,000 Btu/h at 5°F, plus a 10 kW electric resistance air handler. The contractor set the compressor lockout at 30°F and left the thermostat's auxiliary-heat staging at factory defaults.
786 words, about 4 min2Rooftop VAV With Simultaneous Hot and Cold Zones and an Economizer at Minimum
An office building has four 25-ton packaged rooftop units with variable-frequency supply fans, VAV boxes with hot-water reheat, economizers, and CO2-based demand-controlled ventilation. Supply fan speed is controlled to a duct static pressure setpoint of 2.0 in.
854 words, about 4 min3Chilled Water Plant That Cannot Reach Design Tons Without a Third Chiller
A campus chilled water plant has two identical 400-ton centrifugal chillers in a primary-variable configuration serving 60 air handlers with two-way modulating coil valves. Design is 44°F supply, 56°F return, a 12°F delta-T.
893 words, about 4 min4Restaurant Hood Losing Capture With a Makeup Air Shortfall
A 120-seat restaurant has a 12 ft Type I hood over a gas range and fryer line. The exhaust fan is set to 4,200 cfm, within the hood manufacturer's listed range, and the dedicated makeup air unit supplies 3,000 cfm of untempered air through four ceiling diffusers mounted directly in front of and above the hood.
877 words, about 4 min5Apartment Boiler With Upper-Floor Air Binding and Near-Boiler Noise After a Pump Change
A four-story, 42 ft tall apartment building has two 1,500 MBH atmospheric cast-iron boilers in the basement, piped in parallel with a single variable-speed circulator located on the return. The compression tank connects to the boiler supply header, and the air separator sits downstream of the pump on the supply.
947 words, about 5 min