Rooftop Units

Six things move the number, and only one of them is the equipment. Tonnage and heating type. Whether the existing curb takes an adapter or has to be replaced. Crane size, which is set by the pick weight at the reach your site allows — a unit you can reach from the lot is a different job from one that needs a long boom across a building. Whether the work happens in business hours or off-hours. Roofing and flashing scope, and who holds the membrane warranty. Permits, inspections and any street or lot closure. We price all six from the survey rather than guessing from the nameplate.

An adapter, in most cases. The existing curb is structurally fine and already correctly flashed into the roof; what has changed is the new unit’s footprint and where its supply and return openings sit. A fabricated adapter bridges the two and keeps the roof penetration untouched, which is usually the cheaper and lower-risk path. You need a new curb when the existing one is rotted, out of level, undersized for the new unit’s weight, or so far off in footprint that an adapter would overhang. That is a decision from measurements, not from a catalogue.

Fifteen to twenty years is the usual band for packaged equipment in this climate, and coastal or industrial exposure pulls it toward the low end because of what salt and airborne chemistry do to the condenser coil. Units on an annual service programme with clean coils, aligned belts and working economizers reliably outlast units that only get looked at when a tenant complains.

Usually, yes. The area under that one unit loses conditioning for the length of the swap; the rest of the building carries on. The part that has to be scheduled is the crane, because it needs ground space, a clear swing path and often a closure. That is why most of our changeouts run on a weekend or overnight. On multi-unit roofs we sequence them so no more than one zone is down at a time, and portable cooling can cover a critical space.

For a contactor, a fan motor or a belt, repair it — those are cheap and the refrigerant is irrelevant. For a compressor failure or a leaking coil on an R-22 machine, do the arithmetic before you commit: you are buying scarce refrigerant into a system old enough that the next failure is already in the post. We will give you the repair number and the changeout number side by side and tell you which one we would spend our own money on.

Because nobody checks it. The economizer brings in outdoor air for free cooling when conditions allow, and it fails quietly — a seized linkage, a burnt-out actuator, a drifting outdoor air sensor or a changeover setting nobody has revisited since startup. The unit keeps cooling on the compressor and the only symptom is a bill nobody questions. We stroke the dampers and verify changeover on every maintenance visit.

Yes, on every major brand of packaged equipment. Plenty of the roofs we maintain were built out by somebody else over twenty years and carry four manufacturers across a dozen units. We inventory what is up there, log it, and service all of it.

Yes. For property managers with multiple sites we build a unit-by-unit asset list with age, model, refrigerant and condition, then rank the replacements so the capital plan is a schedule rather than a series of surprises. Remote monitoring on the critical units makes that list keep itself current.