What are the consequences of not installing a backflow preventer in an HVAC make-up water system?

Failure to install a backflow preventer in an HVAC make-up water system can lead to contamination of the potable water supply, posing serious health risks to the public. It can also result in system inefficiencies, corrosion, and damage to equipment, leading to costly repairs and downtime. Furthermore, non-compliance with local and national plumbing codes and regulations can lead to fines, penalties, and legal liabilities.