(734) 327 4079 info@ansight.com
AnSight’s Solutions for COVID-19

Thermal Mass Availability for Cooling Data Centers during Power Shutdown

ASHRAE Transactions, Volume 116, Part 2. – Conference Paper, 2010


Kishor Khankari


During power outage servers in the data centers are powered by an uninterrupted power supply (UPS). At the same time, the cooling system components such as CRACs, AHUs, and chillers stop operating for a short period until powered by alternate power sources. During this period servers continue generating heat in the data center room without active cooling. It is common notion that data centers contain large thermal mass, and hence, large heat capacity in the steel rack enclosures to protect servers from the thermal shock due to rising room air temperatures. However, the rate of air temperature rise and the availability of rack thermal mass depend on several factors including the height of the data center room, number of rack enclosures and their size, number of rack rows and their layout, and heat load density of a data center. It is crucial for design engineers and facility managers to know how much time can be available for restarting the active cooling systems before servers reach automatic shutoff temperatures. With the help of a heat transfer model this paper systematically analyzes the effect of various parameters and the impact of rack thermal mass on the time that air requires to reach the thermal shutoff threshold temperature.

Fill the following form to download

    About the author

    Dr. Kishor Khankari

    ASHRAE Fellow, ASHRAE Distinguished Lecturer

    Dr Kishor Khankari is the founder of AnSight LLC. As a specialist in Computational Fluid Dynamics (CFD), his passion for solving engineering problems and providing sound scientific solutions has led to innovations and optimized designs in the industry.

    A noted expert in his field, he has a Ph.D. from the University of Minnesota and has published in several technical journals and trade magazines. As a well sought-after speaker Dr. Khankari makes regular presentations in various technical conferences and professional meetings worldwide.

    Recent Posts

    Ventilation Guidance for Residential Kitchen with Gas Stove

    Recently the residential gas stoves were in the News due to the generation of pollutants during their operation. Cooking activities as well as the combustion of natural gas through gas stove burners produce several indoor pollutants. Exhausting these pollutants from...

    CFD Analysis of Residential Kitchen Ventilation with Gas Stove

    Proper ventilation of the kitchen is essential to reduce the occupant exposure to various pollutants generated during the cooking and the combustion of natural gas through the gas stove burners. Several parameters related to the design and operation can affect the...

    CFD Analysis of Demand Control Ventilation for Laboratories

    What is Demand Control Ventilation (DCV)? Often high air change rates per hour (ACH) are specified for laboratories to meet the goal of ventilation. The ACH numbers specified are mostly consensuses based on simplistic approaches of perfect mixing of contaminants with...

    CFD Analysis Evaluates Efficacy of Reactive Air Cleaning Technology

    What is reactive air cleaning? Reactive air cleaning involves the release of reactive agents in the room to actively mitigate airborne pathogens and other pollutants. Unlike traditional dilution ventilation in which the concentration of the airborne pathogens in the...