Initial value of "zone mean temperature"

asked 2020-04-26 04:22:48 -0600

73 ●4

updated 2020-04-28 00:47:03 -0600

How to set initial value of "zone mean temperature" in Energy+. regardless of HVAC Availability schedule, zone infiltration, occupancy and weather file.

I want Energy+ start the simulate with initial zone mean room temperature at 28 Celsius.

What i get is Energy+ start it by initial 26.6 Celsius (begin simulation) maybe because of my HVAC Availability schedule.

Is there any way I can set the initial value "zone mean temperature" in Energy+?

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answered 2020-04-27 09:41:20 -0600

shorowit

11861 ●201 ●9 https://www.nrel.gov/b...

updated 2020-04-27 09:41:30 -0600

The initial zone temperature is the result of 1) all zones being initialized at 23 deg-C, and 2) the results of a warmup period where the first day of the run period is simulated multiple times until convergence. Whatever zone temperature is calculated at the end of warmup convergence is used for the beginning of the simulation. See the Engineering Reference for more information on this.

The only inputs you can change related to the warmup calculations are found in the Building object, specifically the criteria used for convergence and the min/max number of warmup days.

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Thanks a lot! this is the information that I need.

it's kinda troublesome to fill the warmup calculations just to get initial zone temperature. Doesn't matter it really works.

timotius.kelvin ( 2020-04-29 09:44:56 -0600 )edit

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answered 2020-04-27 11:20:36 -0600

clcs
113 ●3

A workaround that I have used is to create an HVAC thermostat with your initial temperature as heating setpoint, as well as an IdealLoadsAirSystem using that thermostat and with an availibility schedule equals to 1 for the first time steps of your simulation, and 0 afterwards.