Final answer:
Overuse of antifreeze in chilled water systems can impair heat transfer efficiency, increase pumping energy costs, pose environmental risks, and hasten corrosion due to the formation of organic acids.
Step-by-step explanation:
Adding more antifreeze than necessary to prevent freezing in a chilled water piping system can introduce several drawbacks. Overuse of antifreeze, such as ethylene glycol or propylene glycol, can lead to a reduction in the heat transfer efficiency. Since antifreeze has a lower heat capacity compared to water, a higher concentration can mean that the coolant absorbs and releases heat less effectively. Additionally, antifreeze mixtures are more viscous than water, particularly at low temperatures, which can increase the energy required to pump the mixture through the system, leading to higher operating costs.
Furthermore, the excessive addition of antifreeze can lead to increased environmental and health risks, especially if the antifreeze contains toxic substances like ethylene glycol. In case of leaks or improper disposal, these substances can cause harm to the environment and wildlife. Moreover, overconcentration of antifreeze can increase the likelihood of corrosion in the cooling system components, despite the presence of corrosion inhibitors in many commercial antifreeze solutions. This is due to the formation of organic acids that occur when ethylene glycol becomes oxidized.