While residential and commercial air conditioners operate on similar principles, commercial units are typically installed on rooftops and have more robust drainage systems. Commercial structures often use multiple units to provide better efficiency and control.
Residential and commercial HVAC systems are regulated differently. While regulations for residential units may place a premium on safety, commercial units are typically serviced by experts with substantial safety training, so efficiency may take a higher priority. Very large buildings often have one or more rooms dedicated to holding HVAC equipment, which provides easier access should the system experience problems.
Since commercial air conditioners are generally much larger than residential units, extra time is taken ensuring that units are sized correctly. Air conditioners are least efficient when they first start running; units that operate continuously are the most efficient. Building owners often pay extra to precisely determine the right size for their units and the optimal operating profile. Condensation is also a significant consideration for commercial units, so ample drainage is essential.
Commercial units are generally louder than residential units, so regulations often mandate that large units be placed on top of buildings to limit noise pollution. This placement also allows owners to use more space, which helps units eliminate the heat they capture.