Arkansas HVACR NewsMagazine January 2026

ARHVACR NewsMagazine January 2026

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Kirk’s Corner Installation Best Practices for High Efficiency Furnaces Avoiding Common Pitfalls for HVAC Contractors High-efficiency furnaces (90%+ AFUE) continue to gain market share across Arkansas as homeowners look for lower operating costs and improved comfort. While these systems offer clear advantages, they also introduce installation complexities that can lead to premature failures, safety concerns, or costly callbacks if not handled correctly. This article outlines best practices for HVAC contractors, focusing on the most common problem areas: PVC venting, condensate management, and proper sizing and airflow in increasingly tight homes.

Best Practices • Use

manufacturer approved materials only: Not all PVC is equal. Schedule 40 PVC is common, but some manufacturers require CPVC or polypropylene in specific applications. Always follow the installation manual. • Maintain proper slope: Vent pipes must slope back toward the furnace (typically ¼ inch per foot) to allow condensate to drain safely. Improper slope can lead to frozen vents in Arkansas winters or water accumulation in low spots. • Limit vent length and elbows: Exceeding maximum equivalent vent length reduces combustion air flow and causes pressure switch issues. Count every elbow — especially in retrofit installs. • Terminate correctly for Arkansas conditions: Avoid low termination points where heavy rain, snow, or landscaping can obstruct airflow. Sidewall terminations should be clear of shrubs and positioned to avoid recirculation of exhaust gases.

1. PVC Venting: More Than “Just Pipe”

Unlike 80% furnaces that rely on metal flue venting, high-efficiency units use PVC, CPVC, or polypropylene venting systems. Improper vent installation can cause startup failures and nuisance lockouts.