Not recommended for DIY. Requires specialized knowledge of HVAC systems, fuel gas piping, electrical wiring, refrigeration, and comprehensive understanding of the 2024 IRC, 2023 NEC, and Illinois Plumbing Code. Professional installation ensures safety, efficiency, and code compliance.
Direct replacement projects for HVAC systems are generally considered low to moderate complexity when performed by qualified professionals. Key complexities arise from ensuring proper sizing, ventilation, fuel gas piping, electrical connections, and condensate management according to current codes, as well as adherence to local permitting and inspection processes. Deviations from existing layouts or significant upgrades may increase complexity.
Project Guidelines & Rules
Permitting & Planning
4 Rules
Obtain required permits from your local building department prior to commencement of work.
2024 IRC R105.1, R105.2
Verify contractor licensing and insurance requirements with your local municipality.
DuPage County Regional Standard
Ensure proper load calculations (e.g., Manual J for heating/cooling, Manual S for equipment selection) are performed for optimal system sizing.
2024 IRC M1401.3
Provide necessary documentation (e.g., plans, load calculations, equipment specifications) as required by the local building department.
2024 IRC R106.1
HVAC Unit Requirements
4 Rules
All new and replacement HVAC equipment shall be listed and labeled for their intended use.
2024 IRC M1301.1
Outdoor condensing units must be installed on a level, stable surface, typically a concrete pad, with adequate clearance for service and airflow as per manufacturer's instructions.
2024 IRC M1305.1.4
Equipment requiring access for service or maintenance shall be provided with unobstructed passageways and clearances.
2024 IRC M1305.1
Outdoor units shall be protected against physical damage.
2024 IRC M1305.1.3
Fuel Gas Piping (for Furnaces)
8 Rules
All gas piping installations and replacements shall conform to the requirements of the IRC Fuel Gas Code.
2024 IRC Chapter 24 (Fuel Gas)
Proper sizing of gas piping based on BTU load and length is mandatory.
2024 IRC G2413.4
Approved gas piping materials (e.g., black steel, CSST with proper bonding) shall be used.
2024 IRC G2414.4
Accessible shutoff valves shall be installed upstream of each appliance.
2024 IRC G2420.5
All new gas piping installations or modifications shall be pressure tested prior to concealment and use.
2024 IRC G2417.1
CSST (Corrugated Stainless Steel Tubing) installations require proper bonding and grounding.
2024 IRC G2411.2, 2023 NEC 250.104(B)
Ensure proper combustion air supply for gas-fired appliances.
2024 IRC G2407.1
Venting systems for fuel-burning appliances must be installed in accordance with manufacturer's instructions and code, ensuring proper draft and termination.
2024 IRC G2427.1, G2427.6
Electrical Requirements
7 Rules
All electrical wiring and connections must comply with the National Electrical Code.
2023 NEC (NFPA 70)
Dedicated circuit(s) are required for furnace and AC units, as specified by manufacturer and code.
2023 NEC 210.23(A)
Proper overcurrent protection (circuit breakers/fuses) sized according to equipment nameplate data is essential.
2023 NEC 240.4, 430.52
An accessible disconnect switch is required within sight of the outdoor unit and the indoor furnace/air handler.
2023 NEC 440.14, 422.31
All electrical components and wiring in damp or wet locations must be listed for such use.
2023 NEC 110.11
Grounding and bonding of all non-current-carrying metal parts is mandatory.
2023 NEC 250.4, 250.104
Conductors must be adequately sized for the connected load.
2023 NEC 310.15
Condensate Drainage (for AC & High-Efficiency Furnaces)
5 Rules
Condensate lines shall be properly sloped (minimum 1/8 inch per foot) and routed to an approved indirect waste receptor.
Illinois Plumbing Code 890.1370, 2024 IRC M1411.3
Condensate drainage shall not discharge into a storm sewer, onto the ground, or into any area that would create a nuisance or public health hazard.
Illinois Plumbing Code 890.1370(c), 2024 IRC M1411.3
An auxiliary drain pan or safety shutoff switch is required for all cooling coils or evaporators located in an attic or above a finished ceiling.
2024 IRC M1411.6, M1411.6.1
Condensate pumps, if used, must discharge to an approved location and be listed for their intended use.
2024 IRC M1411.3.1
Condensate lines must be protected from freezing in unconditioned spaces, particularly in DuPage County's climate, to prevent damage and improper drainage.
2024 IRC M1411.3, DuPage County Regional Standard
Ductwork & Air Distribution
4 Rules
All new and modified ductwork must be properly sealed to prevent air leakage and ensure system efficiency.
2024 IRC M1601.4.1
Duct insulation R-values in unconditioned spaces shall comply with current energy efficiency requirements.
2024 IRC N1103.2.1 (R403.2.1)
Proper mastic or approved tape must be used for sealing duct connections.
2024 IRC M1601.4.1
Return air openings must not be located in unconditioned attics, garages, or utility rooms where contaminants may be drawn into the conditioned space.
2024 IRC M1602.2
Carbon Monoxide (CO) Alarms
1 Rules
Carbon monoxide alarms are required in all dwelling units with fuel-fired appliances or attached garages.
2024 IRC R315.1, Illinois Carbon Monoxide Detector Act
Inspections
3 Rules
Schedule required inspections with your local building department, which may include rough-in (gas/electrical/plumbing), and final inspections.
2024 IRC R109.1
Ensure all work is accessible for inspection at the time of scheduled visits.
2024 IRC R109.1.5
Provide all necessary equipment manuals, relevant permits, and approved plans on-site for inspectors.
2024 IRC R109.3
Top Rated HVAC Pros in Lake County
GW Jones Heating & Cooling Inc.
