A HVAC fan coil is a device used in heating, ventilation, and air conditioning (HVAC) systems to move air through the system. It consists of a fan, a coil, and a set of ducts. The fan draws air into the system, the coil heats or cools the air, and the ducts distribute the air throughout the building. The fan coil is an important part of any HVAC system, as it is responsible for circulating air throughout the building. It helps to regulate the temperature and humidity of the air, as well as filter out pollutants and allergens. The fan coil also helps to reduce energy costs by allowing the system to run more efficiently. The fan coil is an essential component of any HVAC system, and it is important to maintain it properly in order to ensure that the system is running efficiently and effectively.