The most common indicators are reduced airflow from supply registers, spaces that consistently fail to reach setpoint, unusual noise from the unit, visible moisture or drain pan overflow, increased energy consumption without a change in occupancy or usage, and tenant or occupant comfort complaints that can't be traced to the thermostat or controls. Any of these warrant a service call. In many cases the underlying issue — a fouled coil, a worn belt, a failing motor bearing — is caught and resolved well before it causes a full system failure.

At minimum once per year, typically before peak cooling season. Facilities with higher dust loads, specific IAQ requirements, or units serving densely occupied spaces may benefit from twice-yearly cleaning. Coil fouling is one of the most common and most overlooked causes of degraded AHU performance — even a thin layer of buildup on the coil surface measurably reduces heat transfer efficiency and increases energy consumption. We inspect coil condition on every maintenance visit and recommend cleaning based on actual observed condition rather than a fixed schedule.

An air handler (AHU) is a larger central unit that conditions and distributes air through a ductwork system serving an entire floor or zone. It typically includes a blower, heating and cooling coils, filters, and often an economizer and outside air section. A fan coil unit (FCU) is a smaller, self-contained unit installed directly in the space it serves — typically in individual rooms or zones — and connected to a central chilled water or hot water system rather than a duct network. Both require regular service, but the scope and access considerations differ significantly. Many commercial buildings use both, with AHUs handling primary air distribution and FCUs providing supplemental zone control.

Reprogramming is the right first step when a VFD is faulting due to parameter drift, incorrect acceleration and deceleration ramp settings, or communication errors with the BAS — all of which can often be resolved without hardware replacement. Replacement is typically warranted when the drive has sustained internal damage from power surges or heat, when fault codes indicate failed output transistors or capacitor degradation, or when the unit is old enough that repair parts are no longer available and downtime risk outweighs replacement cost. Friedman Mechanical diagnoses the full VFD chain before recommending hardware replacement, and we carry common drive sizes to reduce lead time when replacement is the right call.

Yes. We specify and install MERV-rated media upgrades, HEPA filtration systems, and UV germicidal units for facilities with indoor air quality requirements driven by building standards, tenant expectations, healthcare regulations, or code compliance. Filter upgrades are often evaluated alongside coil cleaning and AHU maintenance since filter performance and coil condition are directly related — an undersized or poorly sealed filter rack allows bypass air that fouls coils faster and defeats IAQ improvements downstream. We assess the full air handling system and recommend upgrades based on your facility's actual airflow, pressure drop tolerance, and compliance requirements.