Thermostat Setting

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I have a model that does not seem to be switching the thermostat between
heating and cooling. When I output the hourly data for the Zone Thermostat
Setting it seems to always be the heating setpoints (70 occupied and 64
unoccupied). Any idea why this wouldn't be changing over to cooling
setpoints (75 occupied and 82 unoccupied) during the warmer months?

Thanks in advance.

Susan F's picture
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Joined: 2011-09-30
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Susan,

While in detailed data edit go onto one of your thermal zone spreadsheets to
look at your schedules. You will be able to see them easily from there. Make
sure you haven't accidentally put your heating schedule in where your
cooling schedule should be. If this doesn't work zip up your .inp and .pd2
files and send them to us.

Good luck,
Carol

cmg750's picture
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Joined: 2010-10-05
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Unfortunately due to the sensitive nature of the project I cannot send the
files. I have checked and my heating/cooling schedules are assigned to the
right locations.

Could it be related to the design temperatures I have indicated for each
zone? The tstat schedules are as I have stated below but I have the design
temperatures at 74 cooling and 72 heating. The load temperature (in the
space definition) is 70. My throttling range is 2. Would any of this cause
problems?

Susan F's picture
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Joined: 2011-09-30
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Can't you just remove the sensitive project information from the files?
A text editor should allow you to find any "incriminating evidence" and
you can switch the weather file location so we won't even know where in
the world it's located :-) Unless you're modeling the pentagon, in which
case I'll quiet down.

And I doubt this is it, but you might want to double check your header
in the hourly report to make sure you're not looking at just the heating
setpoint (see attached pg.2 and below). The space isn't being cooled at
all, correct?

Eric O'Neill's picture
Joined: 2011-09-30
Reputation: 0

Just re-name the file "not-a-top-secret-nuclear-facility.pd2". Should be all good.

Timothy Howe, MS, LEED? AP

Howe, Timothy's picture
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Joined: 2011-09-30
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I think I can point Susan in the right direction at least. First read this:

For example, if the heating/cooling setpoints are 70/75, the throttling
range is 0.5F (throttling range is centered about the setpoint), then the
heating/cooling trigger temperatures for these reports are 68.75F and 76.25F
(half the throttling range plus 1F).

So you have 72 for heating and 74 for cooling. That means for heating your
trigger temperature is 72 +/- 2F +/- 1F for 69F and 75F , for cooling you
have 71F and 77F. So your heating/cooling trigger temperatures are crossing.
That seems like it could cause a problem like you are experiencing.

WRT to the other temp, 70 F in the space, read the online help for setting
this temp and follow it.

Cheers,
Carol

cmg750's picture
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Joined: 2010-10-05
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I had the same problem when I changed the settings.  I think your explanation would apply to my case too? Carol could you please take a look, thanks!

http://energy-models.com/forum/energy-modeling-software/equest/different-temperature-settings-same-results

Lourdes Gutierrez
GRA - Rochester Institute of Technology
LEED AP BD+C
lmg4630@rit.edu

LouluGuti's picture
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Joined: 2014-02-03
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