Roshan Anand

ORCID Identifier(s)


Graduation Semester and Year




Document Type


Degree Name

Master of Science in Mechanical Engineering


Mechanical and Aerospace Engineering

First Advisor

Dereje Agonafer


Data centers are virtual or physical infrastructure utilized by enterprises to house computer, server and networking systems and other vital components for the needs of the company’s information technology mainly serving the purpose of storing, processing and serving large amounts of mission critical data to clients. As data centers house a network’s most critical systems and are extremely vital for the continuity of daily operations, every organization prioritizes the reliability and security of data centers and their information. A remarkable amount of data center energy is consumed in eliminating the heat generated by Information Technology (IT) equipment to maintain and ensure safe operating conditions and optimum performance. Therefore, energy efficient cooling of data centers is of utmost importance. Airside economization is being encouraged to reduce the associated cooling costs by limiting the operational hours of computer room air conditioning (CRAC) units. The installation of ASEs bears the risk of particulate contamination in data centers, hence, deteriorating the reliability of information technology (IT) equipment. The relative humidity (RH) has a significant effect on the physical form of the accumulated dust particles and in turn the safe operation of the IT equipment. It is necessary and informational to have a clear understanding of the terms ‘Critical Relative Humidity (CRH)’ and the ‘Deliquescence Relative Humidity (DRH)’. CRH is defined as the relative humidity at which the salt or dust particles just begins to adsorb enough moisture to start becoming electrically conductive. DRH is defined as the relative humidity at which the salt or dust particles begin the formation of a saturated salt solution. When the RH in the data center exceeds the deliquescent relative humidity (DRH) of salts or accumulated particulate matter, it absorbs moisture, becomes wet and subsequently leads to electrical short circuiting because of degraded surface insulation resistance between the closely spaced features on the printed circuit boards (PCB’s). Another concern with this type of failure is the absence of evidence that hinders the process of evaluation and rectification. Therefore, it is imperative to develop a practical test method to determine the DRH value of the accumulated particulate matter found on PCB’s. This thesis is a first attempt to develop and validate an experimental technique attempt to measure the DRH of dust particles by logging the leakage current versus %RH for the particulate matter dispensed on an interdigitated comb coupon. To validate this methodology, the DRH of pure salts like Magnesium Chloride (MgCl2), Ammonium Nitrate (NH4NO3) and Sodium Chloride (NaCl) is determined and their results are then compared with their published values. This methodology can therefore be implemented to help lay a modus operandi of establishing the limiting value or an effective relative humidity envelope to be maintained at a real-world data center facility for its continuous and reliable operation at its respective location.


Data center, Particulate contamination, Critical relative humidity, Deliquescent relative humidity, Experimental technique, Modus operandi


Aerospace Engineering | Engineering | Mechanical Engineering


Degree granted by The University of Texas at Arlington