A fan coil unit system is a type of heating and cooling system that is commonly used in commercial and residential buildings. It consists of a fan, a coil, and a condenser. The fan blows air over the coil, which is filled with a refrigerant. The refrigerant absorbs heat from the air, cooling it down. The condenser then releases the heat into the atmosphere. This process is repeated over and over again, allowing the fan coil unit system to provide efficient heating and cooling. The fan coil unit system is a cost-effective and energy-efficient way to heat and cool a building. It is also relatively easy to install and maintain, making it a popular choice for many homeowners and businesses.