Which component is NOT part of larger air conditioning systems?

In larger air conditioning systems, digital thermostats are preferred over analog programmable thermostats because they offer more precise temperature control, easier programmability, and often include features that allow for integration with smart home technologies. Digital thermostats can provide more functionality, such as learning capabilities to adjust settings based on usage patterns, energy usage tracking, and remote access features via mobile apps.

While analog programmable thermostats can be used in simpler HVAC systems, they lack the advanced features and efficiency enhancements that are typically sought in larger and more complex air conditioning systems. Hence, analog programmable thermostats are not a common component of larger air conditioning setups, making them the correct choice in this context.

The other options — digital thermostats, high-efficiency filters, and variable-speed blowers — are all integral components that contribute to the efficiency and performance of larger air conditioning systems. High-efficiency filters improve air quality and system efficiency, while variable-speed blowers help regulate airflow and reduce energy consumption.