The HVAC Briefing

The Texas Department of Licensing and Regulation finalized adoption of the 2024 UMC following the standard three-year update cycle. This means any HVAC installation, replacement, or major alteration permitted on or after September 1 must meet the 2024 code, even if you quoted the job under 2021 standards. Local AHJs across Texas—from Houston to Dallas to San Antonio—will enforce the new version immediately, with no grace period for projects in bidding.

The 2024 UMC introduces several changes contractors need to bake into daily operations. Combustion air requirements for Category I furnaces now demand more precise calculations, especially in tight construction where mechanical ventilation is present. Refrigerant safety standards have been updated to align with ASHRAE 15-2022, which matters significantly as you transition to A2L refrigerants like R-454B and R-32. Expect inspectors to scrutinize sensor placement, refrigerant detector specs, and ventilation rates in mechanical rooms more carefully than before. Ductwork sections include revised leakage testing protocols—if you're doing commercial work or anything requiring duct testing, the new table values are stricter.

From a business standpoint, start updating your proposal templates this month. Your standard boilerplate language about code compliance should reference the 2024 UMC explicitly for any work scheduled past September 1. If you're quoting larger jobs with longer lead times, clarify in writing which code edition applies—it's determined by permit date, not contract date. This protects you from scope creep when an inspector flags something that was compliant under 2021 but no longer passes.

Stock and training adjustments matter too. Any apprentices or newer techs need to understand the updated combustion air tables—these aren't minor tweaks. If you're doing multifamily or light commercial, the revised ventilation calculations for mixed-use spaces will affect your equipment sizing on makeup air units and ERVs. Plan a crew meeting before September to walk through the most common residential and light commercial changes your team will encounter on inspections.

One overlooked detail: the 2024 edition tightens up appliance labeling and documentation requirements. Inspectors can now require manufacturers' installation instructions at rough-in for certain equipment categories, not just at final. Keep digital copies of install manuals accessible on every truck, especially for condensing furnaces, ductless systems, and anything with complex venting.