In what application would you most likely find point of entry (POE) systems?

Point of entry (POE) systems are typically installed where water enters a building because they are designed to treat the water as it comes into the structure, ensuring that the entire water supply is conditioned before distribution. This is beneficial for improving water quality for all uses within the home, such as cooking, bathing, and cleaning, by removing contaminants from the source water.

In contrast, other options reflect applications typically suited for point of use (POU) systems, which are designed to treat water at specific locations like faucets or appliances. This means that while those locations can benefit from filtration or treatment, they do not serve the entire household's water supply in the way that a POE system does. Thus, the optimal and most common installation for a POE system is right at the building's water entry point.