Average Life Expectancies

Here are a few examples from historical data and experience:

Air conditioning compressor – air cooled, hermetically sealed
12 to 15 years
Air conditioning compressor – water-cooled, hermetically sealed
20 years
Air conditioning compressor – reciprocating20 years
Rooftop heating and air conditioning unit20 years
Copper core boiler – heat exchanger15 to 20 years
Steel core boiler – heat exchanger10 to 15 years
New cast iron core boiler – heat exchanger20 to 25 years
Old cast iron core boiler – heat exchanger30 to 50 years
Steel tube boiler – heat exchanger20 to 40 years
Heat exchanger – standard rooftop unit15 to 20 years
Heat exchanger downstream of a cooling coil (package unit)10 to 20 years
Heat exchanger – standard combustion indoor system20 to 25 years
Cooling tower20 to 25 years
Central chiller20+ years
Air handler30+ years
Gas-fired ceiling-mount unit heater15 to 25 years
Gas-fired ceiling-mount radiant heater20 to 25 years
Built-up asphalt and gravel roof system20 to 25 years
Modified bitumen roof system15 to 20 years
Inverted EPDM rubber or PVC roof system25+ years
Asphalt paving for car parking20 years
Asphalt paving for trucks15 years
Sealed, double glazed windows20 to 30 years
Plywood overhead doors15 to 25 years
Pre-finished steel overhead doors20+ years
Electrical transformer30 years
Electrical switchgear30 years