Fan coil units (also known as FCUs) are a way of heating and cooling many different kinds of spaces – that could be residential, commercial, or industrial. FCUs can help with energy efficiency as well as improve the overall air quality.
In this article we are going to cover everything you need to know in order to make the right choice when buying an FCU. There are a lot of factors in play, and thinking about your requirements ahead of time, particularly around the size of the room and how discreet you want the unit to be, will help you make the right choice. That’s what this guide is VIV designed to help you navigate.
Selecting the right FCU can be challenging though, so in this comprehensive 2025 guide, we’ll go through everything you need to know to make the right choice – including the different types of FCUs and their various applications. We will also do a deep dive into how they work, and we will also examine their many benefits.
By the time you have finished the article, you’ll have what you need to know in order to start thinking seriously about the right FCU for your space. As always, it’s worth speaking to an expert like Daikin who can give you professional advice and ensure you get the best tailored solution.
So let’s get started.
What are fan coil units?
Let’s start by defining exactly what we’re talking about. A fan coil unit is basically a system that helps regulate a room’s temperature. It doesn’t use ductwork and works using a fan that pushes air over an indoor coil that is filled with refrigerant. In turn, the refrigerant absorbs (or releases) heat depending. The treated air is then circulated into the space.
You will often find FCUs in offices and commercial spaces, and even in some homes. We will get into the different types of FCUs in more detail later, but essentially there are two distinct versions – either vertical fan coils (VFCs) and horizontal fan coils (HFCs). The former are generally mounted on walls or ceilings (great for tighter spaces) while HFCs sit on floors or ceilings and therefore work better for larger areas.
Types of fan coil units
Let’s now look at the different types of fan coil units. The two main types are horizontal and vertical, but we will look at additional ones here as well:
Horizontal: As you might expert, these are installed in a horizontal position and are generally found in hotel rooms and apartments. Their main benefit is that they are compact and they are quiet. You’ll usually see them mounted on ceilings or walls.
Vertical: Designed for vertical installation, these units can be mounted on either the floor or the ceiling. They are often used in large commercial buildings or multi-storey residential complexes. There needs to be plenty of room to install them.
Cassette: These are units mounted on ceilings which are often used in commercial offices. They are compact so they can sit flush with the ceiling and are generally efficient and discreet.
High-wall: Positioned high on walls, these are ideal for residential spaces and hotel rooms where space is at a premium. They’re also quiet and can be controlled remotely.
Concealed: These are in ceilings or closets so they are not in-sight, usually because it’s important to maintain the style of the interior design.
Benefits of using fan coil units
Let’s now look at the benefits of using fan coil units:
Efficiency: Fan coil systems provide targeted heating and cooling so they reduce energy consumption and lower your utility costs. Because they’re so efficient you are only controlling the climate where it’s needed and so minimising waste.
Flexible: These systems can be tailored to suit a number of different architectural needs, including mitred corners and curved installations. They can integrate with patio or French doors and come in a wide range of grille colours and patterns.
Easy installation: As well as being simple to install, FCUs are low-maintenance with easy access for cleaning and servicing. So they’re a hassle-free solution for long-term use.
Discreet: These systems provide comfortable heating and cooling without a lot of noise. They integrate into flooring and work well with any finish including wood, carpet and many others.
Air quality: Low air turbulence reduces the circulation of dust and allergens, creating a healthier indoor
Factors to consider when choosing a fan coil unit
Selecting the right FCU depends on a number of different factors. Here are the main considerations to keep in mind:
Room size & capacity: Ensure the FCU’s heating and cooling capacity matches the size of the room. Units with too little power may struggle to maintain a comfortable temperature, while oversized units can lead to inefficiency and unnecessary energy costs.
Installation type: Consider whether a horizontal, vertical, cassette, high-wall, or concealed unit best suits your space. Horizontal and concealed units are great for discreet installation, while vertical and high-wall options work well in larger areas.
Aesthetic & space constraints: If maintaining a seamless interior design is a priority, opt for a concealed or floor-integrated system. Alternatively, cassette and high-wall units provide a sleek and compact solution for modern spaces.
Noise levels: If quiet operation is important—such as in bedrooms, offices, or hospitality settings—choose a unit with low-noise performance to ensure minimal disruption.
Maintenance & accessibility: Consider how easy it will be to clean and service the unit. Some designs offer easier access for maintenance, making them more convenient for long-term use.
Integration with Other Systems: If the FCU will be used alongside other heating or cooling solutions, ensure compatibility with radiant heating, underfloor systems, or central HVAC setups.
By assessing these factors, you can choose an FCU that delivers the best balance of efficiency, comfort, and aesthetics for your space.
About Daikin
Daikin is a global innovator in air conditioning and HVAC systems. We offer a complete range of systems to meet the needs of residential, commercial, and industrial clients. From packaged units and split systems to ductless mini-splits and advanced VRF (VRV) technology, Daikin products are engineered for optimal performance, energy efficiency, and comfort year-round.
Daikin leads the industry in innovation and customer support and has business in 170 countries with millions of systems installed. Learn more about Daikin’s HVAC products by contacting us today.
