Indoor climate control systems often rely on air handling units (AHUs) and fan coil units (FCUs) to regulate temperature, manage humidity, and improve air quality. While these two components may appear similar to the untrained eye, there are key distinctions in how AHUs and FCUs operate — differences that matter when selecting the right HVAC system for your specific needs.
At General Air, our HVAC specialists break down the differences between air handling units vs. fan coil units and explain how each contributes to safe, efficient climate control in your home, restaurant, or commercial property.
What is a Fan Coil Unit?
Fan coil units, also known as FCUs, are small single pieces of equipment that condition air and distribute it to the spaces in an area without ductwork. The FCU can be a standalone or part of an HVAC system typically mounted on or near walls or ceilings in individual rooms or zones. Here are some types of FCUs:
- Horizontal above a ceiling void fan coils: These fan coil units are installed above the ceiling, typically in a suspended ceiling void, so they are hidden from view. The cooled or heated air is delivered through ductwork or grilles in the ceiling.
- Horizontal exposed fan coils: Horizontal exposed fan coils are typically installed in open spaces, close to the ceiling, and are visible. These are often used in commercial spaces, like warehouses, where aesthetics are not a primary concern.
- Underfloor fan coils: These fan coil units are installed beneath the floor, often in a raised floor system. Underfloor fan coils are designed for spaces where ceiling installation is not feasible or desired.
- Wall-mounted fan coils: Wall-mounted fan coils are installed on the interior walls of a room. These units are often used in hotel rooms, bedrooms, or small office spaces.
What is an Air Handling Unit?
The air handler is an indoor unit of an HVAC system used to distribute air throughout the indoor space. An AHU works with an HVAC system’s heating and cooling components to supply adequate heating and cooling without consuming a lot of energy. Several types of air handlers can be used with commercial and residential HVAC systems, including:
- Single-speed air handlers: These handlers operate at maximum capacity whenever you turn them on. It means you have minimal control in regulating the heating or cooling output.
- Multi-speed air handlers: Multi-speed blower motors feature two or even three distinct operational levels instead of the single level in single-speed handlers. These handlers initially start at maximum output but subsequently transition to lower settings. This allows the handler to achieve more efficient heating or cooling while minimizing energy consumption.
- Variable-speed air handlers: Variable-speed air handlers can adjust their operation automatically to different speeds in response to the prevailing temperature conditions in a given space. Variable-speed air handlers offer several distinct advantages, including better temperature regulation, enhanced air quality, noise reduction, and optimized energy efficiency.
Should I Pick an FCU or an AHU?
When comparing air handling units vs fan coil units, FCUs are simpler systems consisting of just a coil and fan, making them self-contained. On the other hand, AHUs are complex and larger units with several components.
AHUs are part of a central air system featuring intricate ductwork that distributes air.
AHUs draw air from the outside and pass it to an HVAC system, where it is conditioned.
FCUs can only condition the air already present in an environment by drawing it in and passing it through their heating or cooling coil.
FCUs are ideal for conditioning small areas, while AHUs are used to heat or cool larger spaces.
- When to choose an FCU: Opt for an FCU if you intend to cool or heat smaller areas such as residential rooms. You can also opt for an FCU if your primary goal is to control costs and reduce project complexity.
- When to choose an AHU: An AHU is ideal for large office buildings that require ducts to diffuse and replace air. AHUs are designed for air distribution and filtration. They can handle larger air volumes and maintain consistent air quality throughout a building. These provide better energy management in larger, more complex systems.
Before you pick any unit for your cooling or heating needs, consult with a General Air HVAC professional to evaluate your requirements and make an informed decision.
HVAC Experts in Greenville, South Carolina
AHUs and FCUs have distinct design, functionality, and application characteristics. When deciding between the two units, ensure your choice aligns with your specific HVAC needs, the size and type of your building or space, and your budget.
At General Air, our HVAC professionals have the expertise to assess your specific building requirements, including size, layout, occupancy, and usage. We can provide a system that optimally meets your heating and cooling needs. Contact us today to schedule a free consultation.
Image credit: Dmitriy Kuznietsov / Shutterstock
