What is the maximum altitude for single pack operation in the ERJ 170/175?

The maximum altitude for single pack operation in the ERJ 170/175 is indeed 31,000 feet. This limitation is critical for ensuring passenger comfort and cabin pressure maintenance when operating with one environmental control pack. Above this altitude, the aircraft relies on dual packs to maintain adequate cabin conditions. Single pack operation generally limits the performance of the environmental control system, as one pack must manage the entire cabin pressure and temperature needs. Thus, this altitude restriction is an important operational consideration for the safety and well-being of passengers and crew during flight.