The Importance of a Condo Fan Coil Unit


A condo fan coil unit is an important part of any condo. It helps regulate the temperature and keeps you comfortable all year long. In this post, we will discuss the importance of a fan coil unit, as well as tips for installation and maintenance.

What is a fan coil unit and what does it do?

A fan coil unit (FCU), sometimes referred to as a “condo furnace”, is a type of heating and cooling system that is commonly used in condominiums, apartments, seniors homes, hotels, and other residential buildings. The FCU consists of a fan, a coil, and a set of controls. The coil inside the unit is heated or chilled by a liquid, usually water, circulating through a system of risers, pumps, a boiler, and a chiller. The fan draws ambient air from the room through a filter and blows it across a coil, causing a heat transfer. That conditioned air is then circulated back out into the room. The controls allow the user to set the desired temperature and adjust the speed of the fan. Most residential buildings have a 2-pipe system, in which only heating is available in the winter and cooling in the summer. Some residential buildings, usually hotels or high-end condominiums, have a 4-pipe system, allowing for
heating and cooling all year round.

The Benefits of Replacing Your Fan Coil Unit

Realtor Photo

A new fan coil unit can be listed as a feature when selling your property, adding thousands of dollars to your home’s value, just as new granite countertops would. An older fan coil that is mouldy or leaking might make your property more difficult to sell if the issue is highlighted on your property status certificate.

Age, humidity, lack of maintenance, and fiberglass deterioration are common issues resulting in mould growth. A Unilux replacement unit uses closed cell foam insulation with anti-microbial properties in place of fiberglass to prevent moisture absorption and deterioration.

The volume of air emitted diminishes over time due to a buildup of debris on the underside of the coil. A new fan coil solves this issue.

Motors are one of the most important components in a vertical fan coil unit. Newer motors consume much less energy. The new manifold plumbing system prevents water from needlessly circulating when the system is off.

A study by WT&A Engineering found the new retrofit fan coils to be 5 dB quieter than existing fan coils.

Older models of fan coils have flat drain pans, which allows for pooling and corrosion over time, creating risks of the pan to overflow and cause a flood. Unilux drain pans are sloped towards the center so that water can drain down instead of pooling.

How to choose the right fan coil unit for your condo


If you are considering replacing a FCU in your condo, be sure to speak with the manufacturer or the building’s engineering partner to ensure that it is properly sized for your space. To determine the manufacturer, simply open the access door and look for the name plate, either on the inside door or on the bottom of the cabinet. 94% of fan coils in Canada are manufactured by Unilux.

Your original fan coil will have been sized by the designing engineer of the condominium. This size will have been based on the square footage of your apartment and heat loss properties of your windows and walls. The resulting BTU calculation for all fan coils in the building is summed together to determine the size of the risers, pumps, chiller, and boiler.

If your replacement fan is not sized properly, your unit could adversely affect the building’s heating and cooling system, and you could be liable to rectify this.

Annual fan coil maintenance

To keep your FCU running properly, it is important that a certified technician performs semi-annual maintenance. This includes cleaning the coils, replacing the filter, and flushing the drain line. Additionally, they should check the fans for any wear and tear. It may also be necessary to change the FCU if it becomes mouldy. Unilux uses a particular type of insulation because it is mold-resistant. By following these simple maintenance tips, the FCU will continue to run smoothly for years to come.

Common problems with fan coil units and how to solve them

Fan coil units can experience several problems, such as poor airflow, water leaks, and noise due to worn parts. Freezing of the coil and a resulting flood can also develop but are rare and usually due to accidental misuse.

Here are some common FCU problems and how to solve them:

Poor Airflow

As fan coils age, the motor may not work to its fully capacity or the coil may become clogged with debris, resulting in reduced airflow. This problem can be solved by replacing the blower motor, cleaning the coil, or replacing the entire FCU.

Water Leaks

If the unit is leaking water, it could be due to a clogged drain line or a problem with the condensate pan. A certified technician would solve this problem by cleaning the drain line and ensuring the pan is level. New fan coils come with a flood sensor that shuts off power to the unit and has an audible alarm when water reaches the sensor point.

Coils Freezing

As mentioned above, this is rarely a problem and is most often caused by accidental misuse. A careless resident may leave the window or patio door open during the winter. When the fan coil turns on, a sudden draw of cold air could freeze the coil, causing it to burst. New coils can be equipped with a freeze sensor designed to trigger water flow in the case of a door or window being left open in cold weather.

In the event of these or any other malfunctions, contact your property manager or a certified technician to have the necessary maintenance performed.


The air filters in fan coil units are specifically designed to protect the fan coil unit and improve the air you breathe by trapping dirt and dust. Doing so helps to keep the unit running efficiently and prevents dirt and dust from building up inside the unit, which could lead to several problems. They are also designed to improve indoor air quality.

Older fan coils use a “polywire fabric filter,” which does little more than filter out dust. The Unilux retrofit fan coil uses a MERV8 filter. MERV stands for Minimum Efficiency Reporting Value, and the number informs consumers of which pollutants are trapped by the filter, such as pollen, dust mites, mould spores, pet dander, bacteria, and tobacco smoke. MERV8 filters will trap particles as small as three microns and is the optimal rating for residential applications.

The two most common sizes are 14”x20″x1” and 18”x20″x1”

The fan coil is typically located in the wall of the condo living room or bedroom  behind an access panel. Very seldomly is it located in the ceiling. You can count the number of fan coils you have by counting the access panels, or by counting the thermostats.

Fan coil units typically last for  20 years. However, this can vary depending on the quality of the unit, the amount of use it receives, and the type of environment in which it is used. Some of Unilux’s original 50-year old fan coils are still in operations. By following the proper regular maintenance procedures, you can help to extend the life of your fan coil unit. To determine how much longer your fan coil has left, it is best to consult the manufacturer.

Yes, there are several advantages to replacing a unit. Some of these benefits include improved efficiency, reduced noise levels, and a longer lifespan with fewer fan coil repairs. Additionally, fan coil retrofits can help to improve indoor air quality and thermal comfort. By upgrading your fan coil unit, you can enjoy all of these benefits and more.

Fan coil units have been used in residential buildings and condominiums since the 1970s. Unilux was one of the he first companies to develop fan coils specifically designed for multi residential buildings. . Unilux is credited with introducing a variety of features that made fan coils perfect for residential use, like thick insulation and noise reduction technology.

Due to their high energy performance, reliability, low maintenance requirements, and cost-effectiveness relative to other heating and cooling solutions on the market today, fan coil units continue to be one of the most popular choices for home heating air conditioning across different climates worldwide.

An HVAC (Heating, Ventilation, and Air Conditioning) system is a collection of components that work together to heat and cool indoor air while providing improved indoor air quality. It typically includes elements such as filters, dampers, furnaces, evaporators/cooling coils, cooling towers/condensers, fans & blowers that work together to pump conditioned air into a space.


HVAC systems are designed to provide optimal comfort for occupants in both the summer and the winter months. These HVAC systems help maintain proper ventilation in a space by controlling the room’s temperature to keep it within comfortable levels for people working or living inside it. By circulating fresh outdoor air through an HVAC system and then returning reconditioned indoor air back into the room or building via vents/air ducts/registers, you’re able to create a healthier environment with reduced dust and other particles that can cause health issues or discomfort. 


In addition to keeping people comfortable all year round through regulation of temperature levels & humidity control, these systems also serve another important purpose – energy efficiency & conservation. Many new-age HVAC systems are equipped with advanced controls that allow users to adjust settings depending on their needs; this helps reduce energy costs while still maintaining adequate temperatures when needed most throughout different seasons – again leading towards greater energy savings over time.

Most thermostats are designed for single family homes and will not function with fan coils. However there are a few designed specifically for fan coils. 

Most FCU thermostats before the 2010s rely on 120v power. For these, the most common thermostat is either the original Honeywell dial thermostat. If these homeowners want a digital thermostat, the best option is a Honeywell TB6575A1000. These are very simple to use. 


Thermostats on fan coils installed after the 2010s, and Unilux retrofit fan coils, use a 24v power. With these, the simplest and most intuitive thermostat is the Honeywell TB8575A1000, also called the Suite Pro. They look the exact same as the 120v TB6575 except for a small mark on the back denoting the voltage.

All Smart Thermostats use 24v power. In the last few years, Ecobee has expanded their thermostat’s functionality to include fan coils. In our testing we have found all Ecobees to be very reliable and simple to install. If you purchase your Ecobee from a big box store, it could be from old inventory that has not yet had its software updated to support a FCU.


Nest Smart Thermostat also work with FCU but are not as reliable and installation takes longer. Honeywell is currently testing a Smart Thermostat to work with fan coils.

A 2-pipe fan coil system is a closed loop heating and cooling system connected by risers to a chiller, boiler, and pumps. The two pipes refer to the two risers, which branch out into the FCU, one to supply the tempered water and one to return it. A building using a 2-pipe will only be able to either heat (in the winter) or cool (in the summer). 


Some buildings are equipped with an electric auxiliary heating element. They are used to provide heat on the cooler spring and fall days when the system is still in cooling mode. 


There is also a third riser – for condensate liquid. In the summer, the warm humid air condenses against the cold coils. The condensation collects in a drain pan and drains down the third riser. Improper drainage in older fan coils is the leading cause of floods.

A 4-pipe fan coil system expands on the 2-pipe system by having two extra risers, four in total. One to supply the hot water, one to return it, a third to supply the cold water, and the last to return it. These buildings have the ability to provide heating and cooling all year round.