HVAC Service Interval & Cost Estimator

Estimate how often your HVAC system needs professional servicing and what it will cost annually, based on system type, age, usage intensity, and environmental conditions.

Formulas Used

Service Visits per Year:

visits = base_visits(system_type)
        + age_adder(age)          ← +0.5 if age > 10 yrs; +1.0 if age > 15 yrs
        × usage_multiplier        ← 0.85 (low) → 1.35 (very high)

Service Interval (months) = 12 ÷ visits_per_year

Cost per Visit:

cost_per_visit = base_cost(system_type)
               × [1 + age_surcharge]      ← 2% per yr over 10 yrs, max 40%
               × [1 + env_surcharge]      ← 0–20% for environment
               × location_labor_index     ← 0.85–1.30

Annual Costs:

annual_service_cost   = visits_per_year × cost_per_visit × (1 − contract_discount)
annual_filter_cost    = (12 ÷ filter_change_interval_months) × filter_unit_cost
total_annual_cost     = annual_service_cost + annual_filter_cost

Remaining Life (yrs)  = expected_lifespan(system_type) − system_age
% Life Used           = (system_age ÷ expected_lifespan) × 100

Assumptions & References

  • Base service visit frequencies follow ACCA (Air Conditioning Contractors of America) and ASHRAE residential maintenance guidelines.
  • Base visit costs ($100–$160) are derived from HomeAdvisor / Angi national averages (2023–2024).
  • Expected system lifespans: Central AC & Heat Pump = 15 yrs; Furnace = 20 yrs; Boiler = 25 yrs; Mini-Split = 20 yrs; Package Unit = 15 yrs (DOE / ASHRAE).