What Drives Commercial HVAC Preventive Maintenance Cost?

Property managers ask us for a price on HVAC maintenance before we have seen the building. We understand why. But two buildings with the same square footage can have maintenance costs that are nowhere near each other. One might have six rooftop units on an easy roof. The other might have a chiller plant, a cooling tower, twenty air handlers and a roof you reach through a hatch in a janitor's closet.

So instead of a price, here is what actually drives the cost of a commercial HVAC preventive maintenance agreement in South Florida. If you understand these factors, you can compare proposals fairly and spot the ones that cut corners.

Equipment type

This is the biggest factor. A packaged rooftop unit is relatively simple. A visit means checking refrigerant operation, cleaning or replacing filters, checking belts and motors, cleaning the condenser coil, clearing the condensate drain and checking controls.

A chiller is a different scale of work. Water cooled chillers need log reviews, oil analysis, refrigerant checks, condenser tube cleaning and periodic eddy current testing. Cooling towers need regular inspection and cleaning and coordination with water treatment. Air handlers need coil cleaning, belt and bearing service and damper checks. A building with a central plant needs more skilled hours per visit and more specialized work through the year.

Split systems, ductless units, packaged terminal units in hotels, VAV boxes, exhaust fans and makeup air units all add their own tasks.

Tonnage and number of units

More equipment means more labor. But it is not just the total tonnage. Twenty five small units take longer than five big ones with the same total capacity, because each unit has its own filters, belts, drains, coils and controls.

How often you want visits

ASHRAE Standard 180 lays out minimum inspection and maintenance tasks for commercial HVAC systems and their frequencies. In South Florida, equipment runs nearly year round, so quarterly visits are common for rooftop units and monthly or more frequent attention is common for chiller plants. Some owners want monthly filter changes in dusty or high occupancy buildings. More visits cost more, but they also catch problems earlier.

We usually suggest matching visit frequency to how the building is used, not to a standard package. A medical office with long hours and humidity concerns needs a different schedule than a warehouse office used 40 hours a week.

Filters

Filter cost depends on how many you have, what size, and what rating. Higher MERV filters cost more and may need to be changed more often in some systems. Hospitals, labs and some offices require specific filtration. The number of filter changes per year has a big effect on the total.

Access

Roof access is a real cost factor. Is there a fixed ladder or a stair to the roof? Do technicians need a lift to reach equipment? Are units on a high rise roof that requires the freight elevator and a building escort? Is there equipment above ceilings in occupied tenant spaces that can only be reached after hours? All of that adds time.

Age and condition

Older equipment takes more time to maintain and fails more often. A twenty year old rooftop unit with corroded coils and patched wiring needs more attention than a two year old unit. Some agreements include a set amount of repair coverage. Others cover only the maintenance tasks, with repairs quoted separately. Know which one you are comparing.

Coastal exposure

Buildings near the ocean or the Intracoastal deal with salt corrosion. Coils need more frequent cleaning and protective treatment, and electrical connections and fasteners need closer inspection. That adds time on every visit, but it extends equipment life significantly.

Water treatment

If you have a cooling tower, water treatment is a separate cost, often handled by a specialist vendor. Some mechanical contractors include it or coordinate it. Make sure your proposal is clear about who is responsible for chemical treatment, testing and the water management program described in ASHRAE Standard 188.

Controls

Buildings with building automation systems can be easier to maintain, because trends and alarms show problems before a technician arrives. But someone has to maintain the controls too: sensors, actuators, programming and network hardware. That may be part of the agreement or separate.

After hours requirements

Hotels, hospitals, retail and restaurants often want maintenance done when the space is closed. After hours and weekend labor costs more. Planning visits for off peak times can help, but some buildings simply require it.

Response time and coverage

Agreements that include priority response, after hours emergency coverage, or guaranteed arrival times cost more than basic maintenance. For a hospital or data room, that coverage is worth it. For a small office it may not be.

What is included and excluded

This is where proposals differ the most. Read the scope carefully. Does it include refrigerant? Belts and filters? Coil cleaning with chemicals or just water? Condensate drain treatment? Condenser tube cleaning? Annual reports? A cheap proposal often has a short scope.

How to compare proposals

Ask each contractor for the list of tasks per visit, the visit frequency for each piece of equipment, what parts and materials are included, and how repairs are priced. Make sure they have actually walked the building. A proposal written without a site visit is a guess.

The cost of skipping maintenance

We are not going to pretend maintenance pays for itself in every case. But in South Florida, an HVAC system that is not maintained usually shows it within a year: dirty coils, clogged drains, failing capacitors, refrigerant leaks and high energy bills. Emergency repairs during the summer almost always cost more than the maintenance that would have prevented them.

Get a real number

We build maintenance agreements after we walk the building and inventory the equipment. Read about our commercial HVAC service, then call 954.577.7923 or request a site visit.