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Changing anti-cycling period

asked 2020-07-02 21:49:58 -0500

Aly ElHefny's avatar

updated 2020-07-03 17:51:03 -0500

Hello everyone, Hope you are all in good health and high spirit.

I'm trying to understand why my single speed dx-coil action is delayed at higher cycling frequencies. It seems that the coil is having an anti-cycling period of about 3.5 minutes from the results I've tested. But I can't find that in the manual to confirm. Where can I find this in energyplus documentation ? and is there a way I can change this value ?

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Thanks and stay safe !

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What "order" did you give?

rraustad's avatar rraustad  ( 2020-07-02 21:54:49 -0500 )edit

turn on cooling coil

Aly ElHefny's avatar Aly ElHefny  ( 2020-07-02 21:56:10 -0500 )edit

Well, of course, but how did you command the coil to turn on? EMS? External Interface?, etc.

rraustad's avatar rraustad  ( 2020-07-02 21:57:16 -0500 )edit

External interface, so give order on = (availability = 1 and SP is lower the current temperature at a desired value), are there built-in anti-cycling periods in energyplus ?

Aly ElHefny's avatar Aly ElHefny  ( 2020-07-02 21:58:58 -0500 )edit

Perfect. This gives other viewers some perspective on your method. Unfortunately I am not a user of external interfaces. I do know the coil models pretty well. Could you provide a more macro level plot of temp vs time when using a "detailed" reporting frequency so that we can see the response in real (simulated) time? Maybe that won't help but I don't know until I see it.

rraustad's avatar rraustad  ( 2020-07-02 22:05:30 -0500 )edit

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answered 2020-07-02 22:35:05 -0500

Without knowing what time scale the interface is using with E+, I will explain that if the zone temperature changes by more that 0.3 C then the HVAC time step in E+ will be reduced proportionally to the temperature change. So for example, if your time step is 10 min, and the change in zone temp is 1 C, then the HVAC simulation time step will be reduced to 3.33 minutes. What you need to do is view temperature vs time using the most detailed time step possible.

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I'm both simulating and viewing at 1 minute timestep. Is there a built-in anticycling period in energyplus ? because I've been searching the manuals and didn't have luck in confirming this point.

Aly ElHefny's avatar Aly ElHefny  ( 2020-07-03 00:38:37 -0500 )edit

I am not aware of any anticycling in E+. Use a detailed reporting frequency as: Output:Variable,*,Variable Name,Detailed;

rraustad's avatar rraustad  ( 2020-07-22 10:06:54 -0500 )edit

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Asked: 2020-07-02 21:49:58 -0500

Seen: 112 times

Last updated: Jul 02 '20