Planned vs reactive aircon maintenance: the real cost

Reactive maintenance looks cheaper because the invoice only arrives when something breaks. That single number is the trap. It counts the repair and ignores everything the failure dragged in with it: the emergency call-out premium, the hours the space ran hot, and the occupants who escalated while it did.

Running a unit to failure also costs more than fixing it on schedule. A coil left fouled until it chokes does not just need a clean by then. It has worked the compressor harder for months and may have taken a part down with it. The deferred saving is really borrowed against a larger bill later.

The comparison that matters is not repair cost against servicing cost. It is the full cost of a failure, premium and downtime included, against the planned visit that would have prevented it. Once that is the frame, reactive stops looking cheap on the units that actually matter.

The gap between the two approaches is easiest to see line by line. The table sets the same failure against what each approach actually pays for it.

The reactive column only looks cheaper if the failure never happens. On a unit that runs hard or sits in front of occupants it always eventually does, and the premium-plus-downtime line is where a planned cycle pays for itself several times over.

Reactive maintenance is not always the wrong choice, and treating it as such over-spends. For a single low-stakes unit in a back room, a space nobody occupies for long, or a unit already near the end of its life, waiting for a fault can be the rational call. There is little downtime cost to insure against.

The honest test is what a failure would actually cost. Where that number is small, a planned cycle is insurance against a risk that barely exists. Buying scheduled servicing for every unit regardless of stakes is how a maintenance budget inflates without reducing any real risk.

Four factors decide when planned maintenance starts winning, and they compound. Unit count is the first: one unit is easy to watch, but nobody notices the third of forty quietly degrading until it fails. The more units there are, the more value in a cycle that catches the drift early.

Criticality is the second and the heaviest. A unit cooling a public lobby, a server room, or an occupied floor carries a failure cost that a store cupboard never will. Age is the third, since older units fail more often and less predictably. Downtime cost is the fourth, and it is the one most often left out of the sum.

For facilities managers running several sites, these factors rarely point the same way across a portfolio. The lobby and the server room sit at one end, the rarely-used back office at the other. The right plan treats them differently rather than averaging them into one blanket contract.

Most buildings are best served by a mix, not a single policy. Planned cycles for the critical and occupant-facing units, lighter or reactive cover for the low-stakes ones, with the line drawn by what a failure would cost rather than by habit. That is where the budget does the most work.

On the repairs themselves, the diagnosis still has to come before the quote. A reactive call-out under time pressure is exactly when a unit gets a guessed part rather than a found fault, which is how a managed budget pays for work the unit never needed. One accountable contractor who diagnoses first keeps both the planned and the reactive side honest.