The Summer or WinterDesignDay may be in the wrong place of your schedule, and shut off the system regardless.
Turn on the Daytype Index variable to see the actual day used in the simulation.
Because the AHU is setpoint based on a reference node, the VAV damper position does not control the fan velocity diretly. When the zone temperature is not met, the damper will move towards the maximum or minimum position and lock.
If the ref. set point is at 50°C for the AHU in the cooling mode, and the zone temperature is below this, the AHU fan would not be turned on. To use the OA in take, the economizer must be on, and the ref set point is ignored. This may also depends on what set point manager is used.
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Continuous fan is on all the time. Constant speed fan has a fixed volume. VAV fan would change it speed to maintain the reference set point temperature, by change the air flow through the coils.
In the cooling mode, the reference set point temperature must not be higher than the desired zone temperature.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: jeannieboef@xxxxxxxxx
Date: Thu, 29 Sep 2011 17:37:25 +0000
Subject: [EnergyPlus_Support] fan problem
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Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
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Turn on the Daytype Index variable to see the actual day used in the simulation.
Because the AHU is setpoint based on a reference node, the VAV damper position does not control the fan velocity diretly. When the zone temperature is not met, the damper will move towards the maximum or minimum position and lock.
If the ref. set point is at 50°C for the AHU in the cooling mode, and the zone temperature is below this, the AHU fan would not be turned on. To use the OA in take, the economizer must be on, and the ref set point is ignored. This may also depends on what set point manager is used.
===============================
Continuous fan is on all the time. Constant speed fan has a fixed volume. VAV fan would change it speed to maintain the reference set point temperature, by change the air flow through the coils.
In the cooling mode, the reference set point temperature must not be higher than the desired zone temperature.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: jeannieboef@xxxxxxxxx
Date: Thu, 29 Sep 2011 17:37:25 +0000
Subject: [EnergyPlus_Support] fan problem
Dear group,
I am doing a summer design day analysis.
I am using AHU fan:variablevolume with zone vav:noreheat and notice that the AHU fan will not run regarless of damper positions or outdoor air requirements if there are no space loads to meet (because I set the cooling setpoint to 50 deg C.)
This is unwanted behaviour.
My cooling loads are combated with a seperate radiant cooling system which has a setpoint of 22 deg C.
The objective is to de-couple the cooling function of the AHU to a pure ODA functionality.
As I understand the io ref, the only fan type that doesn't operate to meet loads is continuous.
Comments please.
I am doing a summer design day analysis.
I am using AHU fan:variablevolume with zone vav:noreheat and notice that the AHU fan will not run regarless of damper positions or outdoor air requirements if there are no space loads to meet (because I set the cooling setpoint to 50 deg C.)
This is unwanted behaviour.
My cooling loads are combated with a seperate radiant cooling system which has a setpoint of 22 deg C.
The objective is to de-couple the cooling function of the AHU to a pure ODA functionality.
As I understand the io ref, the only fan type that doesn't operate to meet loads is continuous.
Comments please.
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
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