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What is the default strategy in EnergyPlus to maintain the temperature in 2 Zone Data Center?

asked 2018-09-18 17:02:48 -0500

sdsa's avatar

updated 2018-09-18 19:21:19 -0500


I am new to EnergyPlus. I was reading the 2 Zone Data Center IDF file provided by the Energy Plus. The name of the idf file is 2ZoneDataCenterHVAC_wEconomizer.idf. One can find this IDF file with the EnergyPlus installed. I was trying to find the strategy that EnergyPlus used to maintain the temperature inside the data center. Concretely, given the outside temperature and zone temperatures, how EnergyPlus change the setpoint temperatures and valve rate to maintain the zone temperature close to the target temperature.

Thank you,


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answered 2018-09-25 14:06:06 -0500

This example file has two air loops, each serving one zone. It uses two SetpointManager:SingleZone:Cooling objects to set the required supply air temperature for each air loop. Each system has a dry-bulb economizer, direct evaporative cooler, indirect evaporative cooler, DX cooling coil, and chilled water cooling coil. Each component attempts to meet the supply air setpoint and will remain off if the incoming air is already at the setpoint. As noted in the header comments, one of the system has the chilled water coil scheduled off at all times, and the other has the DX coil scheduled off.

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Thank you MJ Write. I had some questions. 1. What is the equation by which we change the temperature. My understanding is as following. There is present zone temperature (25 degree). We want to change this zone temperature to a target temperature (For example 23 degree). We have a set point temperature that is our control. My question is how should we change this set point temperature to make the zone temperature same as target temperature. 2. There is also Variable Valve Rate Fan. How do we change the valve rate of the Fan to match the target temperature?

Thanks a lot

sdsa's avatar sdsa  ( 2018-09-25 18:04:54 -0500 )edit

The zone heat balance determines the load required to meet the thermostat setpoint. This load is reportable as an Output:Variable:: Zone Predicted Sensible Load to Cooling Setpoint Heat Transfer Rate. Based on that load and the supply air flow rate to the zone, the SetpointManager:SingleZone:Cooling object determines the required supply air temperature setpoint use the relationship of load = massflow * deltaT * Cp. Regarding question 2, I'm not sure why the author of this file used VAV air terminals. The single zone cooling SPM is more appropriate for constant volume systems.

MJWitte's avatar MJWitte  ( 2018-10-04 14:28:07 -0500 )edit

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Asked: 2018-09-18 17:02:48 -0500

Seen: 313 times

Last updated: Sep 25 '18