How Does A Rooftop Air Handler Differ From An Indoor Air Handler?

How Does A Rooftop Air Handler Differ From An Indoor Air Handler?

Rooftop air handlers (RTUs) and indoor air handlers differ most notably in installation location, which drives differences in design, function, and ideal use cases. RTUs are self-contained units for outdoor rooftop use, while indoor units are part of split systems and stay inside the building.

1. Installation Location & Space Impact

Rooftop Air Handler (RTU): Installed exclusively on building rooftops. This eliminates the need for indoor or ground space, which is critical for dense commercial areas.

Indoor Air Handler: Mounted inside the building, often in utility rooms, basements, attics, or ceiling cavities. It requires dedicated indoor space, which can be a constraint in small homes or offices.

2. Design & Component Integration

Rooftop Air Handler (RTU): A fully self-contained unit. It integrates all necessary components—fans, filters, heating/cooling coils, and often compressors—into one weather-sealed casing. The casing is also built to resist outdoor elements like rain, wind, and extreme temperatures.

Indoor Air Handler: A partial system component. It only includes core parts like fans, filters, and coils (for air distribution). It relies on a separate outdoor unit (e.g., a heat pump or condenser) to generate heated/cooled refrigerant, which is piped to the indoor handler.

3. Ideal Use Cases

Rooftop Air Handler (RTU): Designed for large commercial buildings. This includes malls, office towers, schools, and retail centers where indoor/ground space is limited, and centralized climate control is needed for multiple zones.

Indoor Air Handler: Suited for residential spaces (homes, apartments) and small commercial areas (e.g., small offices, clinics). It works best where outdoor unit installation (e.g., on a patio or side of the building) is feasible, and space for a split system is available.

4. Noise & Maintenance Access

Rooftop Air Handler (RTU): Minimizes indoor noise. Since the unit is on the roof, operational sounds (from fans or compressors) do not disturb indoor occupants. Maintenance requires rooftop access, which may need specialized equipment (e.g., ladders, lifts).

Indoor Air Handler: Operates quietly indoors (most models are sound-dampened), but maintenance is more accessible. Technicians can service the unit without rooftop access, making routine checks (e.g., filter changes, coil cleaning) faster.