Idaho - HVAC JOURNEYMAN EXAM

Key Concepts

Code Title and Scope (Section 101)

• Code Title: Known as the "Mechanical Code of [NAME OF JURISDICTION]" (Section 101.1)
• Scope Coverage: Regulates design, installation, maintenance, alteration, and inspection of permanently installed mechanical systems for environmental control (Section 101.2)
• Key Exception: Detached one- and two-family dwellings and townhouses (not more than 3 stories) follow the International Residential Code, not the IMC
• Fuel Gas Systems: Regulated by International Fuel Gas Code, not IMC
• Appendices: Do not apply unless specifically adopted by jurisdiction (Section 101.2.1)

Key Concepts

Scope and Application (Section 201) - Section 201.1: All terms in Chapter 2 apply throughout the entire IMC unless expressly stated otherwise - Section 201.2: Present tense includes future; masculine includes all genders; singular includes plural - Section 201.3: Terms not defined in IMC but defined in other I-Codes (IBC, IFC, IFGC, IPC) use those definitions - Section 201.4: Undefined terms use "ordinarily accepted meanings" based on context

Critical HVAC System Definitions (Section 202) - Air Conditioning: Treatment of air controlling temperature, humidity, cleanliness, AND distribution simultaneously - Air-Conditioning System: Heat exchangers, blowers, filters, supply/exhaust/return ducts, and connected apparatus - Air Distribution System: Any system of ducts, plenums, and air-handling equipment circulating air within spaces - **Air-Handling…

Key Concepts

Section 301 - General Requirements - 301.2 Energy Utilization: All HVAC systems must be designed for efficient energy use per the International Energy Conservation Code - 301.3 Identification: Every pipe, tubing, and fitting must bear manufacturer identification - 301.4 Plastic Components: Plastic pipe, fittings, and components require third-party certification to NSF 14 - 301.5 Third-Party Testing: All piping, tubing, and fittings must be tested by approved third-party agency OR certified by approved certification agency - 301.7 Listed and Labeled: All appliances must be listed and labeled for their specific application (Exception: refrigeration equipment follows Section 1101.2)

Key Concepts

Section 401.1 - Scope: Chapter 4 governs ventilation of occupied spaces. Mechanical exhaust systems, hazardous exhaust, dust/stock/refuse conveyors, subslab soil exhaust, and smoke control systems fall under Chapter 5, not Chapter 4.

Section 401.2 - Ventilation Required: Every occupied space must be ventilated by either natural means (Section 402) or mechanical means (Section 403). Special requirement: Dwelling units with air infiltration rates less than 5 air changes per hour (tested with blower door at 0.2-inch water column/50 Pa) must use mechanical ventilation. Ambulatory care facilities and Group I-2 occupancies require mechanical ventilation only.

Section 401.3 - When Required: Ventilation must be provided during periods when the room or space is occupied.

Key Concepts

Section 501.2 - Independent System Requirements - Single or combined mechanical exhaust systems for environmental air must be independent of all other exhaust systems - Dryer exhaust must be independent of all other systems - Type I exhaust systems must be independent except as provided in Section 506.3.5 - Type II exhaust systems for food-processing operations must be independent of all other exhaust systems

Section 501.3 - Exhaust Discharge Requirements - All mechanical exhaust must discharge outdoors at a point that won't cause public nuisance - Cannot discharge into attics, crawl spaces, or onto walkways - Must discharge where air cannot be readily drawn back in by ventilating systems - Exception: Whole-house ventilation-type attic fans can discharge…

Key Concepts

Section 601 - General Requirements

• Scope (601.1): All duct systems for air conditioning, heating, ventilating, and exhaust must comply with Chapter 6, except when specified in Chapters 5 and 7
• Air Movement in Egress Elements (601.2): Corridors SHALL NOT serve as supply, return, exhaust, relief, or ventilation air ducts
• Exception: Makeup air for toilet rooms, bathrooms, dressing rooms if corridor is directly supplied with outdoor air at greater rate than makeup air taken
• Exception: Return air within dwelling units and tenant spaces ≤1,000 sq ft
• Contamination Prevention (601.4): Exhaust ducts under positive pressure, chimneys, and vents cannot extend into or pass through ducts or plenums
• Return Air Opening Restrictions (601.5): Return…

Key Concepts

Section 801.1 - Scope: Chapter 8 governs factory-built chimneys, chimney liners, vents, and connectors. It also covers utilization of masonry chimneys. Critical: Gas-fired appliances are governed by the International Fuel Gas Code, NOT Chapter 8.

Section 801.2 - General Venting Requirement: Every fuel-burning appliance must discharge combustion products to a vent, factory-built chimney, or masonry chimney. Exception: Commercial cooking appliances vented by Type I hood per Section 507.

Section 801.4 - Positive Flow: Venting systems must develop positive flow adequate to convey all combustion products to outside atmosphere.

Section 801.6 - Minimum Size: Chimney or vent serving a single appliance must have minimum area equal to the area of the appliance connection (except for engineered systems).

Key Concepts

Section 901 - General Requirements - Chapter 9 governs approval, design, installation, construction, maintenance, alteration and repair of specific appliances and factory-built fireplaces - Gas-fired appliances are regulated by the International Fuel Gas Code, NOT Chapter 9 - Fireplaces and solid fuel-burning appliances are prohibited in hazardous locations (Section 901.3) - In Group I-2, Condition 2 occupancies, solid fuel-burning fireplaces and appliances are completely prohibited (Section 901.4)

Fireplace Types and Standards - Masonry fireplaces: Must comply with International Building Code (Section 902.1) - Factory-built fireplaces: Must be listed, labeled, and installed per UL 127 testing standard (Section 903.1) - Pellet fuel-burning appliances: Must be listed per ASTM E1509 (Section 904.1) - Fireplace stoves: Must be tested per…

Key Concepts

Section 1001 - General Scope and Exceptions Chapter 10 governs installation, alteration, and repair of boilers, water heaters, and pressure vessels. Know the seven specific exceptions, particularly: - Unfired pressure vessels ≤5 cubic feet operating at ≤250 psi in Groups B, F, H, M, R, S, and U occupancies - Pressure vessels in refrigeration systems (regulated by Chapter 11) - Equipment subject to federal or state inspection

Section 1002 - Water Heater Requirements Water heaters must be listed, labeled, and removable without removing permanent building structure. Key standards include: - Domestic electric: UL 174 or UL 1453 - Commercial electric: UL 1453 - Oil-fired: UL 732 - Solid-fuel: UL 2523

Key Concepts

System Scope and Compliance (Section 1101.1) Chapter 11 governs refrigeration systems that vaporize and liquefy fluids during the refrigeration cycle. All systems must comply with both the IMC and ASHRAE 15 standards. Ammonia systems have additional requirements under IIAR 2, 3, 4, and 5 standards.

Factory-Built Equipment Standards (Section 1101.2) Listed and labeled factory-built equipment must be tested per UL 207, 412, 471, or 1995. These units meet code requirements when installed per listing and manufacturer instructions.

System Classification Process (Section 1102.1) Six-step determination process: 1. Classify the refrigeration system (Section 1103.3) 2. Classify the refrigerant (Section 1103.1 and Table 1103.1) 3. Determine maximum refrigerant quantity (Section 1104) 4. Determine enclosure requirements (Section 1104) 5. Apply location…

Key Concepts

Scope and Application (Section 1201.1) Chapter 12 governs 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 water distribution systems are covered under the Idaho State Plumbing Code (ISPC), not IMC.

Sizing Requirements (Section 1201.2) All piping and components must be sized for the actual demand of the system. Undersized systems will fail to meet load requirements.

Alternative Standard (Section 1201.3) As an alternative to Sections 1202 and 1203, systems can be designed per ASME B31.9 standard.

Key Concepts

Scope and Compliance (Section 1301.1-1301.2) Chapter 13 governs design, installation, construction, and repair of fuel-oil storage and piping systems. Fuel-oil storage systems must comply with Section 603.3 of the International Fire Code, while piping systems follow IMC requirements.

Fuel Type Requirements (Section 1301.3) Appliances must be designed for the specific fuel type they will use. Converting an appliance from the fuel specified on its rating plate requires reapproval from the code official.

Anti-siphon Requirements (Section 1301.4) When an oil burner is served by a tank where any part is above the burner inlet connection level and the fuel supply line comes from the tank top, an approved anti-siphon valve or siphon-breaking device must be installed instead of…

Key Concepts

Scope and Applications (Section 1401.1) Solar thermal systems covered include space heating/cooling, domestic hot water heating, swimming pool heating, and process heating. This chapter governs design, construction, installation, alteration, and repair.

Equipment Standards (Section 1401.4) - Solar thermal equipment must conform to ICC 900/SRCC 300 - Systems must be listed and labeled per ICC 900/SRCC 300 - Collectors and panels specifically must be listed per ICC 901/SRCC 100 - Installation must follow manufacturer's instructions and ICC 900/SRCC 300

Potable Water Protection (Section 1401.2) Potable water supplies must be protected against contamination per the International Plumbing Code (Idaho State Plumbing Code). Exception: When all solar system piping is part of the potable water distribution system and all components…

Key Concepts

Code Title and Scope (Section 101) - The code is officially titled "Fuel Gas Code of [NAME OF JURISDICTION]" per Section 101.1 - Section 101.2 defines scope: applies to fuel-gas piping systems, fuel gas appliances, gaseous hydrogen systems, and related accessories - Critical Exception: Detached one- and two-family dwellings and townhouses (not more than 3 stories) with separate egress follow the International Residential Code, NOT the IFGC

Piping System Coverage (Section 101.2.2) - Natural gas: operating pressure ≤ 125 psig (862 kPa gauge) - LP-gas: operating pressure ≤ 20 psig (140 kPa gauge) - Coverage extends from point of delivery to outlet of appliance shutoff valves - Includes design, materials, components, fabrication, assembly, installation, testing, inspection, operation,…

Key Concepts

Section 201 - General Requirements - 201.1 Scope: All definitions in Chapter 2 apply throughout the entire fuel gas code unless specifically stated otherwise - 201.2 Interchangeability: Present tense includes future; masculine includes feminine/neuter; singular includes plural and vice versa - 201.3 Terms Defined in Other Codes: When terms aren't defined in IFGC, refer to International Building Code, International Fire Code, International Mechanical Code, or Idaho State Plumbing Code (ISPC) - NOT International Plumbing Code - 201.4 Terms Not Defined: Use ordinarily accepted meanings based on context

Key Concepts

Section 301 - General Requirements - Listed and Labeled Equipment (301.3): All appliances must be listed and labeled for their specific application unless approved under Section 105 through engineering evaluation - Label Information Requirements (301.5): Permanent factory nameplate must include manufacturer's name/trademark, model number, serial number, testing agency seal, hourly Btu/h rating, approved fuel type, and minimum clearance requirements - Fuel Types (301.7): Appliances must be designed for the specific fuel gas supplied; conversion only allowed with complete manufacturer instructions, gas supplier instructions, or installation instructions

Key Concepts

Scope and Application (Section 401.1) - Chapter 4 governs design, installation, modification, and maintenance of gas piping systems from the point of delivery to appliance connections - Utility service piping within buildings must comply with IBC structural safety and fire protection provisions

Piping Identification Requirements (Section 401.5) - Non-steel exposed piping must have yellow labels marked "Gas" in black letters - Labels spaced at maximum 5-foot intervals - Exception: Labels not required on pipe in same room as appliance served

System Modifications and Additions (Sections 401.3-401.4) - When modifying existing systems, maintain sizes per Chapter 4 requirements - When adding appliances, check existing piping capacity for ALL appliances served - If inadequate capacity, either enlarge existing system…

Key Concepts

Scope and Application (Section 501.1) - Chapter 5 governs factory-built chimneys, chimney liners, vents, and connectors for gas-fired appliances - Masonry chimney construction is regulated by International Building Code - Non-gas fuel appliances are regulated by International Mechanical Code

General Venting Requirements (Section 501.2) - Every appliance must discharge combustion products to the outdoors (with specific exemptions in 501.8) - Venting systems must be sized according to Sections 503 and 504

Appliances Not Required to Be Vented (Section 501.8) Key unvented appliances include: - Ranges and built-in cooking units (listed for optional venting) - Hot plates and laundry stoves - Type 1 clothes dryers (must exhaust per Section 614) - Room heaters listed for unvented use -…

Key Concepts

Scope and Application (Section 601.1) Chapter 6 governs the approval, design, installation, construction, maintenance, alteration and repair of specific gas appliances. This chapter works in conjunction with other IFGC chapters to provide comprehensive appliance requirements.

Decorative Appliances for Fireplaces (Section 602) - Must be tested in accordance with ANSI Z21.60/CSA 6.26 - Manually lighted natural gas decorative appliances tested per ANSI Z21.84 - Flame Safeguard Device Required: All decorative appliances (except ANSI Z21.84 tested units) must have flame safeguard devices that automatically shut off fuel supply when ignition becomes inoperative - Cannot be installed where prohibited by Section 303.3

Key Concepts

Scope and Applications (Section 701.1) Gaseous hydrogen systems must comply with IFGC Chapter 7 AND IFC Chapters 53 and 58. Compressed gases also require compliance with IFC Chapter 50 for general requirements. This multi-code coordination is critical.

System Definition (Section 702.1) A gaseous hydrogen system contains at least 95% hydrogen gas by volume and not more than 1% oxygen by volume. The system includes containers, reactors, regulators, relief devices, manifolds, compressors, and interconnecting piping.

Pressure Relief Device Requirements (Section 703.3) - No valves (shutoffs, check valves, or mechanical restrictions) between pressure relief devices and protected containers (703.3.1) - Exception: Locked-open shutoff valve on containers with multiple relief devices - No restrictions between relief device and atmospheric discharge…