ICC F29 Master Mechanical Exam (2015 IMC/IFGC)
Practice at the real exam's pace
Every practice exam shows your time per question against the real exam's clock (2:24 here), and each topic lands in one of these:
What's on the exam
Questions per topic, out of 100Topics
General Requirements and Plan Reading
Key Concepts
Scope and applicability - The IMC regulates permanently installed mechanical systems; fuel gas piping, gas-fired appliances and their venting are regulated by the International Fuel Gas Code (Section 101.2). Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories high with separate means of egress comply with the International Residential Code (Section 101.2, Exception). - Where a general and a specific requirement conflict, the specific governs; where different sections specify different requirements, the most restrictive governs (Section 102.1). - Where this code conflicts with a referenced standard, the provisions of this code apply (Section 102.8.1; see also 102.8.2). - Existing and new systems shall be maintained; the owner or owner's authorized agent is responsible, and HVAC maintenance inspection is per ASHRAE/ACCA/ANSI Standard 180 (Section 102.3).
Appliances and Equipment
Key Concepts
Water heaters - Gas-fired water heaters shall be tested to ANSI Z21.10.1 and ANSI Z21.10.3 and installed per the manufacturer's instructions (IFGC 624.1). - Water heater requirements for sizing, relief valves, drain pans and scald protection follow the International Plumbing Code — those four items only (IFGC 624.1.1). - Combination potable water-heating/space-heating water heaters shall be listed and labeled for such service and installed per the manufacturer's instructions and the IPC (IFGC 624.2; IMC 1002.2). - Where a combination system needs space-heating water above 140°F, an ASSE 1017 temperature-actuated mixing valve shall temper water to the potable distribution system to 140°F (60°C) or less (IMC 1002.2.2). - Listing standards: oil-fired UL 732; domestic electric UL 174 or UL 1453; commercial electric UL 1453; solid-fuel-fired UL 2523 (IMC 1002.1).
Exhaust and Ventilation Systems
Key Concepts
Exhaust discharge location (IMC 2015, Section 501.3.1) — termination distances differ by what the duct conveys: - Explosive/flammable vapors, fumes or dusts (Item 1): 30 ft from property lines; 10 ft from operable openings into buildings; 6 ft from exterior walls and roofs; 30 ft from combustible walls and operable openings in the direction of discharge; 10 ft above adjoining grade. - Other product-conveying outlets (Item 2): 10 ft from property lines; 3 ft from exterior walls and roofs; 10 ft from operable openings; 10 ft above grade. - Environmental air exhaust (Item 3): 3 ft from property lines; 3 ft from operable openings into buildings other than Group U; not less than 10 ft from mechanical air intakes.
Duct Systems
2015 International Mechanical Code (IMC) — Chapter 6, Duct Systems
Key Concepts
Duct classification and metal construction - Ducts are classified by maximum operating pressure, positive or negative: 0.5, 1.0, 2.0, 3.0, 4.0, 6.0 or 10.0 inches of water column (IMC 603.3). The classification selected must equal or exceed the system design pressure. There is no 2.5-, 5.0- or 8.0-inch class. - Round metallic duct joints: mechanically fastened with not less than three sheet metal screws or rivets equally spaced around the joint; where partially inaccessible, three fasteners are equally spaced on the exposed portion to prevent a hinge effect (IMC 603.4.1). - Crimp joints in round and oval metal duct: lapped not less than 1 inch (25 mm), male end extending into the adjoining duct in the direction of airflow (IMC 603.4.2). - Table 603.4 (single dwelling units)…
Combustion Air
2015 IFGC / 2015 IMC
Key Concepts
Scope and method selection - Combustion, ventilation and dilution air shall be provided by one of the methods in Sections 304.5 through 304.9. Where the requirements of Section 304.5 are not met, outdoor air shall be introduced per 304.6 through 304.9. Direct-vent appliances, gas appliances of other than natural draft design, vented gas appliances not designated Category I, and appliances with power burners follow the manufacturer's instructions (IFGC 304.1). - IMC 701.1: Solid fuel-burning appliances — combustion air per the manufacturer's installation instructions; oil-fired appliances — per NFPA 31; gas-fired appliance combustion and dilution air — per the International Fuel Gas Code. The methods in IMC Chapter 7 do not apply to fireplaces, fireplace stoves and direct-vent appliances. - IMC 701.2: Volume, smoke or fire dampers in combustion air openings shall be…
Chimneys and Vents
Key Concepts
Connections to chimneys (IFGC 501.9; IMC 801.12). Connectors shall connect to a masonry chimney flue at a point not less than 12 inches above the lowest portion of the interior of the chimney flue.
Cleanouts (IFGC 501.15.3; IMC 801.13). Masonry chimney flues shall have a cleanout opening of minimum height 6 inches, with the upper edge not less than 6 inches below the lowest chimney inlet opening, fitted with a tight-fitting, noncombustible cover.
Unvented appliance limit (IFGC 501.8). Where the appliances in Items 5 through 11 (counter appliances, refrigerators, room heaters listed for unvented use, direct-fired makeup air heaters, other appliances listed for unvented use and not provided with flue collars, specialized appliances of limited input such as laboratory burners and gas lights, etc.) are installed so that aggregate input **exceeds 20 Btu per hour per cubic…
Fuel Supply Systems
Key Concepts
Sizing methods (402.4.1–402.4.3). Under the longest length method, each section is sized using the longest length of piping from the point of delivery to the most remote outlet and the load of that section — one length row sizes everything. Under the branch length method, the longest run is sized first using its own length and section loads; each branch not previously sized then uses the length from the point of delivery to the most remote outlet in that branch. Hybrid systems size high-pressure piping to the most remote line pressure regulator, then regulator-to-outlet piping separately (402.4.3).
Demand and pressure (402.2, 402.5, 402.6). Total connected hourly load is the basis for sizing, assuming simultaneous full-capacity operation. Maximum design operating pressure inside buildings shall not exceed 5 psig except where: the system is welded; the piping is in…
Special Requirements
Key Concepts
Refrigerant quantities and change of refrigerant - The refrigerant type in a circuit containing more than 220 pounds (99.8 kg) of Group A1 or 30 pounds (13.6 kg) of any other group shall not be changed without prior notification to the code official and compliance with the applicable code provisions for the new refrigerant type (1101.8). - A machinery room is not required for listed equipment and appliances containing not more than 6.6 pounds (3 kg) of refrigerant, regardless of safety classification, where installed per the listing and manufacturer's instructions (1104.2, Exception 1). - A hood and exhaust system complying with Section 510 is required where a device having an open flame or a surface temperature greater than 800°F (427°C) is used in a room containing more than 6.6 pounds (3 kg) of refrigerant in a single…
Electrical
Key Concepts
Electrical wiring, controls and connections — NFPA 70 (IMC 2015, Section 301.10) Electrical wiring, controls and connections to equipment and appliances regulated by the IMC shall be in accordance with NFPA 70. The IMC does not restate NFPA 70's rules; it points to that standard as the governing document.
Label information — general nameplate content (IMC 2015, Section 301.9) A permanent factory-applied nameplate(s) shall be affixed to appliances, with the following in legible lettering: - Manufacturer's name or trademark - Model number - Serial number - The seal or mark of the approved agency
The label shall also include category-specific information. Note that each list below belongs to its own appliance category — do not mix them.
Water
Source: IMC 2015, Chapter 12 — Hydronic Piping
Key Concepts
Scope (1201.1). Chapter 12 governs construction, installation, alteration and repair of hydronic piping systems that are part of HVAC systems, including steam, hot water, chilled water, steam condensate and ground source heat pump loop systems. Potable cold and hot water distribution is installed per the International Plumbing Code. As an alternative to Sections 1202 and 1203, piping may be designed, installed, inspected and tested in accordance with ASME B31.9 (1201.3).
Used materials — two opposite rules. - Hydronic piping (1202.2): Reused pipe, fittings, valves or other materials shall be clean and free of foreign materials and shall be approved by the code official for reuse. - Ground-source heat pump loops (1210.2): Reused pipe, fittings, valves, and other materials shall not be permitted — no approval pathway exists.