The design of mechanical systems begins with accurate load estimation and system sizing. This is a critical phase that ensures mechanical systems are capable of meeting the building’s requirements for comfort, functionality, and safety. Proper load estimation ensures that systems are neither under-sized nor over-sized, optimizing energy efficiency and operational costs.

In this phase, engineers calculate the heating, cooling, ventilation, water supply, waste removal, and fire protection system requirements based on the building’s size, usage, and occupancy. The sizing of HVAC, plumbing, and fire protection systems depends on a variety of factors, including climate, building type, and specific occupancy needs.

Accurate load estimation also helps determine the appropriate capacity of the mechanical equipment, ductwork, piping, and distribution systems. The results from this phase guide the selection of equipment and the design of the entire mechanical system, ensuring that it performs efficiently over the life cycle of the building. This section will cover the essential subtopics necessary for estimating and sizing mechanical system loads, setting the foundation for the system's proper design and integration within the building.