In newer buildings with a central heating/AC system, fan coils may be located behind a panel in the wall of one or two rooms in each suite along with the thermostat. At the bottom, there is an air filter with the in-vent and above is the motor for the fan and coil with a pan under to prevent condensation from dripping. The exhaust vent is above. A picture is provided below.
When the thermostat is on A/C or heating, the fan simply re-circulates air that is already in the room after the system has either cooled it or warmed it. The air does not come from outside. This is why, if this system is to work properly, no furniture should be placed in front of the grill where the air filter is. This is where the air goes in to be cooled down or heated up.
It’s a good idea to air a room regularly by opening a window but this should be done only when A/C or heating are not on. Otherwise, energy will be wasted and the motor will work harder and burn out prematurely.
Maintenance of the fan coil is carried out by a certified contractor, often a plumber, or by the same contractor who has the contract to maintain a building’s large systems. The contractor removes the filter and changes it. Then he vacuums the system, lubricates it, checks for leakages and the general functioning, including the thermostat. Maintenance is usually done twice a year.
This maintenance is necessary for proper functioning and to prevent leakages as well as mould formation. When furniture is placed in front of the air intake (where the filter is), the system can’t get air in and the motor may burn out prematurely.
Fan coil maintenance is generally owners’ responsibility and they should pay for it. (Check the building’s declaration.) However, managers are well aware that most owners would forget about it, may not hire a proper contractor, and would end up paying far more individually than warranted. As a result of neglect, the entire system would deteriorate much more rapidly. This is why many condominiums do it on behalf of owners and include it in the general budget.
Questions About Air and Ventilation
Why is There So Much Air Coming in From the Door of My Suite?
Unless you open your windows, there is no fresh air that naturally comes in your suite. As a result, air would become stale and unhealthy. As well, in winter, condensation on windows could be a problem and mould could develop.
Air forced into corridors comes directly from the outside. It is “fresh” air. The pressure of this air is designed to compensate for air that goes out of your suite through the kitchen and bathroom exhaust fans. That’s why doors are designed to let some air in all around, especially underneath.
So the air that comes in under the suite door helps a suite from being too humid or the air too stale. It also helps prevent condensation on windows in winter.
When corridors’ ventilation system is controlled, more air is generally pumped in during the days than at night. However, not all buildings have control over the system.
Where Does the Air in the Corridors Come From?
As mentioned above, it comes in directly from the outside from air intake units on the roof. For lower floors, air may come from side units on the ground or basement units that are hidden under large grills.
This corridor air is heated in the winter and constitutes a good portion of the costs of heating in a building. In summertime, the air is cooled and constitutes a sizable portion of the electricity used in the building.
In order to save on energy use and cut costs, corridor air is not warmed to the same extent as is the case in suites during winter time. Similarly, in summer, the air is not cooled to the same extent as it is in suites.