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Plant equipment control in Openstudio 1.9

asked 2015-12-07 09:40:49 -0500

NickC gravatar image

updated 2017-05-17 12:26:57 -0500

Hello UA! I'm curious how people are controlling plant equipment in OS v1.9, scheduling to be exact. Please see the basic HW loop below; I'm wondering how to turn the boiler OFF in the summer and then back ON in the winter. I'd also appreciate some advice on operational ordering of equipment (for example, assume that there are two boilers in the loop). How would you control which boiler meets the HW heating load first in OS? Thanks, -N

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Another post that might apply-

Seems like editing PlantEquipmentOperationScheme is the way to go, but I'm interested in staying in the OS environment if possible.

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answered 2015-12-08 17:34:08 -0500

updated 2015-12-09 11:13:53 -0500

The PlantEquipmentOperationScheme objects made it into the back end in 1.9.0, but won't be in the GUI until 1.12.0. In the meantime, you can use a Measure. The following code might be a useful example of how to do this:

# A default constructed load scheme has a single large load range
cooling_op_scheme =
# This method adds the equipment to the existing load range

# This cuts the load range into 5 pieces
peak_cooling_cap = 430000.0 # From running the model
# See PlantEquipmentOperationRangeBasedScheme for details about this api 
# 0-20% Lead
cooling_op_scheme.addLoadRange(0.2 * peak_cooling_cap,[lead_chiller])
# 20-40% Med
cooling_op_scheme.addLoadRange(0.4 * peak_cooling_cap,[med_chiller])
# 40-60% Lead + Med
cooling_op_scheme.addLoadRange(0.6 * peak_cooling_cap,[lead_chiller, med_chiller])
# 60-80% Med + Big
cooling_op_scheme.addLoadRange(0.8 * peak_cooling_cap,[med_chiller, big_chiller])
# 80-100% All Chillers
cooling_op_scheme.addLoadRange(1.0 * peak_cooling_cap,[lead_chiller, med_chiller, big_chiller])


# Set the equipment to run sequentially in each load range.
# See PlantLoop LoadDistributionScheme field documentation for more options.
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Thanks Andrew! Not the answer I was hoping for but certainly the one I was looking for...I'll take your example and see if I can get the measure working. Looking forward to the plant loop functionality.

NickC gravatar imageNickC ( 2015-12-10 17:58:45 -0500 )edit

Has the feature discussed above (operation scheme control) been added to the most recent version of OpenStudio (1.12.0)? If so, I can't seem to find it. I'm looking to schedule a facility that has a hard, seasonal switch from a cooling tower to central chilled water and back once a year.

ethankheil gravatar imageethankheil ( 2016-10-04 12:02:17 -0500 )edit

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Asked: 2015-12-07 09:40:49 -0500

Seen: 320 times

Last updated: Dec 09 '15