MI HVAC study guide
MI HVAC · Work through your exam, one topic at a time.
The Michigan HVAC exam is a licensing assessment used by the state to evaluate whether a candidate has the technical and code knowledge expected of a mechanical contractor working in heating, cooling, and ventilation. It is aimed at people pursuing contractor-level licensure - typically experienced installers and technicians moving into business ownership, or contractors adding HVAC scope to an existing mechanical license - rather than at entry-level apprentices. The MI HVAC study guide has 8 sections and about 2,305 words.
01Heating Systems and Equipment
Candidates must be able to match heat sources to distribution and to explain combustion, electric-resistance, and hydronic heating in plain language. Know the difference between steady-state efficiency and AFUE : AFUE accounts for cycling, jacket, and off-cycle losses, so a furnace rated 80% AFUE delivers less usable heat than its steady-state combustion efficiency suggests.
322 words, about 2 min02Cooling and Refrigeration Systems
Understand the vapor-compression cycle: compressor raises pressure and temperature, condenser rejects heat, metering device drops pressure, evaporator absorbs heat. Know the four components and the state of refrigerant at each point (superheated vapor at compressor inlet, subcooled liquid at metering device inlet).
294 words, about 1 min03Ventilation, Air Distribution, and Ductwork
This domain blends indoor air quality, duct design, and pressure balance. Know the difference between ventilation (intentional outdoor air supply), infiltration (unintentional leakage in), and exfiltration .
293 words, about 1 min04Load Calculations and System Sizing
Candidates must understand that sizing begins with a room-by-room load calculation, not rules of thumb. Know the components of a Manual J-style load: conduction through envelope assemblies, solar gain through glazing, internal gains from occupants and appliances, and latent load from moisture.
288 words, about 1 min05Controls, Electrical, and Safety Devices
This domain tests the interface between control logic, electrical circuits, and safety. Understand line voltage vs.
283 words, about 1 min06Fuel Gas Piping, Combustion, and Venting
Know the properties of natural gas and LP: natural gas is lighter than air and rises; LP is heavier and pools. Understand Btu content (roughly 1,000 Btu/ft³ for natural gas, ~2,500 Btu/ft³ for LP vapor), specific gravity , and why orifice sizing differs between fuels.
284 words, about 1 min07Michigan Codes, Permits, and Licensing Requirements
Candidates should understand that Michigan adopts model codes with state amendments and that local jurisdictions enforce them. Know that HVAC work generally requires a permit and inspection, and that contractors must hold a state mechanical contractor license with a qualified master or journeyman.
273 words, about 1 min08Project Planning, Estimating, and Business Practices
This domain covers the business side: estimating, contracts, scheduling, and customer communication. Understand how to build an estimate from a takeoff (equipment, materials, labor hours), apply overhead and profit , and account for permits, disposal, and contingency.
268 words, about 1 min