Should you be concerned about a 55F chilled water supply used for human comfort, and why?

• A. No, this temperature is ideal for human comfort.
• B. No, this temperature is acceptable for comfort.
• C. Yes, this temperature is too high for human comfort purposes.
• D. Yes, this temperature is too low for human comfort.

Answer: (C)

When people feel comfortable in a cooled space, it isn’t just about the air temperature; moisture removal matters too. The chilled-water temperature in the cooling coil determines how much latent cooling (dehumidification) you can achieve. A supply temperature of 55 F is relatively warm for comfort cooling, which means the coil can remove less moisture from the air. As a result, humidity stays higher and the air feels muggy, even if the space is cooled to the desired temperature.

In practice, engineers design with chilled-water temperatures around the 40s to mid-40s Fahrenheit to provide good dehumidification and comfortable humidity levels. So 55 F is typically not sufficient for reliable comfort, which is why this supply temperature is concerning for human comfort.