Final answer:
Rooftop units are usually located above the space to be served, near the top of the building, to efficiently provide heating, cooling, or ventilation and save internal space.
Step-by-step explanation:
Rooftop units are often positioned above the space that is to be served by the equipment. The placement of these units is typically near the top of the building, directly over the areas where heating, cooling, or ventilation is needed. This positioning allows for easy distribution of airflow throughout the building and a more efficient design since it provides direct access to outdoor air for cooling and ventilation purposes. Additionally, placing the units on the roof frees up valuable floor space inside the building that can be used for other purposes.