1

EP "Small office" model: Temperature oscillations

I compiled an EP prototype building model (Small office, ASHRAE 90.1, 2019, Seattle) into an FMU and studied its behavior. Sometimes, there are strong oscillations in the room temperature when the heat pump/chiller go through repeated on/off cycles. I noticed that this mostly occurs during unoccupied hours.

In the attached plot, you see a few days of operation of one room during summer. On top is the room temperature (setpoint and actual), center-left is the electric and thermal power of the chiller, bottom-left is the power of the fan and bottom-right is the occupancy. Temperatures are in °C, powers are in W and the x-axis is in days.

Is there a way to make this smoother? As far as I understand, EP usually sets the setpoint temperature and then retroactively calculates the necessary heating/cooling power.

C:\fakepath\TemperatureOscillations.png

MPK's avatar
101
MPK
asked 2021-09-21 03:30:58 -0500
__AmirRoth__'s avatar
4.4k
__AmirRoth__
updated 2022-02-06 12:06:35 -0500
edit flag offensive 0 remove flag close merge delete

Comments

add a comment see more comments

1 Answer

1

Look at the fraction radiant factor.

https://bigladdersoftware.com/epx/doc...

In my case, I could reduce the oscillation with increasing this parameter.

BaseboardHeater's avatar
87
BaseboardHeater
answered 2021-09-21 04:02:14 -0500
edit flag offensive 0 remove flag delete link

Comments

add a comment see more comments