The Temperature and Relative Humidity Control in Cushing Library

Abstract

Cushing Library located on TAMU campus is a special building, which needs precise temperature and relative humidity control, because it stores a number of rare collections and memorial books. There are five air-handling units (AHUs) serving the building. This paper will concentrate the unit, which serves the book stacks. This AHU is a multiple zone, constant air volume (MZCAV) system, with reheat and direct digital control (DDC). It has a standard cooling coil, glycol cooling coil, steam humidifier, and heat recovery. The chilled water to the standard cooling coil is served by the chilled water loop on the campus. There is a glycol chiller for the glycol cooling coil for added dehumidification ability. Because of programming problems and hardware problems, the relative humidity was not controlling properly. In this paper, the new control program for temperature and relative humidity control is implemented and the energy savings from the new control program is estimated. The temperature and relative humidity are now under control.