read VRF indoor unit from .idf file and use in .osm file

asked 2018-06-05 13:28:14 -0500

Matt Koch gravatar image

updated 2018-06-05 19:30:18 -0500

I am trying to write a measure that can read VRF indoor and outdoor unit information from a library file in .idf format and create a VRF system in my .osm model. The library section for a sample VRF indoor unit looks as follows:

ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,
Daikin VRV IV FXMQ07PA(PB)VJU,                !- Name
,                                             !- Terminal Unit Availability Schedule
,
,
autosize,                                     !- Supply Air Flow Rate During Cooling Operation {m3/s}
autosize,                                     !- Supply Air Flow Rate When No Cooling is Needed {m3/s}
autosize,                                     !- Supply Air Flow Rate During Heating Operation {m3/s}
autosize,                                     !- Supply Air Flow Rate When No Heating is Needed {m3/s}
autosize,                                     !- Outdoor Air Flow Rate During Cooling Operation {m3/s}
autosize,                                     !- Outdoor Air Flow Rate During Heating Operation {m3/s}
autosize,                                     !- Outdoor Air Flow Rate When No Cooling or Heating is Needed {m3/s}
,                                             !- Supply Air Fan Operating Mode Schedule
,
Fan:OnOff,
Daikin VRV IV FXMQ07PA(PB)VJU Supply Air Fan, !- Supply Air Fan
,
,
Coil:Cooling:DX:VariableRefrigerantFlow,
Daikin VRV IV Indoor Cooling Coil,            !- Cooling Coil
Coil:Heating:DX:VariableRefrigerantFlow,
Daikin VRV IV Indoor Heating Coil,            !- Heating Coil
30,                                           !- Zone Terminal Unit On Parasitic Electric Energy Use {W}
20,                                           !- Zone Terminal Unit Off Parasitic Electric Energy Use {W}
1.0;                                          !- Rated Total Heating Capacity Sizing Ratio {W/W}

This library file is called vrf_library.idf, and in my measure (in the "run" function, not the "arguments" function), I am reading and writing it back to the user via the following measure.rb snippet:

>>>
library = OpenStudio::Workspace::load("#{File.dirname(__FILE__)}/resources/vrf_library.idf").get
library_vrf_in_name = runner.getStringArgumentValue("library_vrfs_in", user_arguments)
library_vrf_in = library.getObjectByTypeAndName("ZoneHVAC_TerminalUnit_VariableRefrigerantFlow".to_IddObjectType,library_vrf_in_name).get

puts "Name = #{library_vrf_in.getString(0).get} \n"
puts "Terminal Unit Availability Schedule = #{library_vrf_in.getString(1).get} \n"

puts "Supply Air Flow Rate During Cooling Operation = #{library_vrf_in.getString(4).get} \n"
puts "Supply Air Flow Rate When No Cooling is Needed = #{library_vrf_in.getString(5).get} \n"
puts "Supply Air Flow Rate During Heating Operation = #{library_vrf_in.getString(6).get} \n"
puts "Supply Air Flow Rate When No Heating is Needed = #{library_vrf_in.getString(7).get} \n"
puts "Outdoor Air Flow Rate During Cooling Operation = #{library_vrf_in.getString(8).get} \n"
puts "Outdoor Air Flow Rate During Heating Operation = #{library_vrf_in.getString(9).get} \n"
puts "Outdoor Air Flow Rate When No Cooling or Heating is Needed  = #{library_vrf_in.getString(10).get} \n"

puts "Supply Air Fan Operating Mode Schedule  = #{library_vrf_in.getString(11).get} \n"

puts "Supply Air Fan = #{library_vrf_in.getString(14).get} \n"

puts "Cooling Coil = #{library_vrf_in.getString(18).get} \n"

puts "Heating Coil = #{library_vrf_in.getString(20).get} \n"
puts "Zone Terminal Unit On Parasitic Electric Energy Use = #{library_vrf_in.getDouble(21).get} \n"
puts "Zone Terminal Unit Off Parasitic Electric Energy Use = #{library_vrf_in.getDouble(22).get} \n"
puts "Rated Total Heating Capacity Sizing Ratio = #{library_vrf_in.getDouble(23).get} \n"
<<<

Strangely, when doing this, neither Supply Air Fan nor Cooling Coil nor Heating Coil get populated in the "puts" output, but everything else does. And when running the following snippet ...

>>>
puts library_vrf_in
<<<

... I get the following output:

ZoneHVAC:TerminalUnit ...
(more)
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Comments

I suggest sharing your idf library file. This is a very lengthy question (=doesn't really make you try hard...), and dependent on what the file does hold, so being able to try it out seems like a requirement.

Julien Marrec gravatar imageJulien Marrec ( 2018-06-07 03:23:04 -0500 )edit

Thanks Julien. How do I share the library file? (I may not have tried smart, but I tried very hard, to the tune of several hours).

Matt Koch gravatar imageMatt Koch ( 2018-06-07 07:04:14 -0500 )edit

Host it wherever, and include the link in your original question (wherever = gist/dropbox/google drive for eg)

Julien Marrec gravatar imageJulien Marrec ( 2018-06-07 08:10:09 -0500 )edit