How Airflow and Static Pressure Measurements Explain the 5000 Rule for Furnaces
The $5000 rule is a practical guideline that compares the cost of repairing a furnace against replacement: if repair costs exceed 50% of a new unit's price, replacement often makes better financial sense. However, the real decision hinges on whether your system's airflow and static-pressure measurements still support efficient operation. When measured CFM benchmarks and static-pressure data fall outside target ranges, even a $5000 repair may fail to restore proper performan