Free tool, Dallas-Fort Worth
Should you repair or replace that rooftop unit?
Enter the unit age and your repair quote. The calculator applies the $5,000 rule guideline and tells you which path usually makes more financial sense.
The $5,000 rule is a commercial HVAC planning guideline: multiply the unit age in years by the estimated repair cost. If that number exceeds $5,000, replacement is usually the better financial move. Below $3,500 and repair typically wins. The calculator below runs that math instantly and flags when age alone is a reason to plan for replacement.
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How the $5,000 rule works
The rule is straightforward: take the unit's age in years and multiply it by the estimated repair cost in dollars. A 10-year-old unit facing an $800 repair scores 8,000, which suggests replacement is worth pricing out. That same $800 repair on a 4-year-old unit scores 3,200, which is comfortably in the repair range. The $5,000 figure is a guideline built from decades of commercial HVAC field data, not a precise formula. Several factors can shift the answer in either direction.
- Unit age is past the roughly 15-year ASHRAE median service life
- System still uses R-22 refrigerant (discontinued; recharging costs have risen sharply)
- Two or more significant repairs in the past 24 months
- Rising energy bills even after recent repairs (a sign of declining efficiency)
- Manufacturer has discontinued parts for the model
Repair or replace: common questions
What is the $5,000 rule for HVAC?
The $5,000 rule is a planning guideline: multiply the unit age in years by the estimated repair cost. If the result exceeds $5,000, replacement typically delivers better long-term value than repair. It is a starting point, not a hard cutoff. Refrigerant type, repair history, and energy costs also matter.
How long does a commercial rooftop unit last?
ASHRAE pegs the median service life of a commercial rooftop unit at roughly 15 years. Units in high-use or high-heat environments like Dallas can fall short of that; units on a regular maintenance plan often exceed it. Once a unit passes 15 years, budget for replacement even if it is still running.
Is it cheaper to repair or replace a commercial AC unit?
It depends on the math. A single repair on a young unit is almost always cheaper upfront. But an aging unit that needs repeat repairs can cost two to three times more per year than a replacement on a maintenance plan. The calculator above runs the $5,000 rule to help you decide. For a unit-by-unit breakdown, request the free Rooftop Risk Report.
Related commercial HVAC services
Start with the building and equipment details.
Share the unit count, age range, service history, and current concern. The screening result helps organize the next conversation, but it is not an inspection, diagnosis, or promise of contractor availability.