.Buildings.Fluid.DXSystems.Cooling.AirSource.Examples.SpaceCooling

Information

This model illustrates the use of the air source DX coil models with single speed compressor, multi-stage compressor, and variable speed compressor. The three systems all have the same simple model for a room, and the same HVAC components, except for the coil. The top system has a DX coil with single speed compressor and on/off control with dead-band. The middle system has a DX coil with two stages, each representing a different compressor speed. The bottom system has a DX coil with variable speed control for the compressor.

All coils are controlled based on the respective room air temperature. The plot below shows how room air temperatures and humidity levels are controlled with the respective coils. The single speed coil has the highest room air humidity level because during its off-time, water that accumulated on the coil evaporates into the air stream. This effect is smaller for the coil with two compressor stages and for the coil with variable compressor speed, as both of these coils switch off less frequent.

Implementation

The model is based on Buildings.Examples.Tutorial.SpaceCooling.System3.

Contents

Name	Description
Medium	Fluid medium for the model
SimpleRoom	Simple model of a room
ControllerTwoStage	Controller for two stage coil

Revisions

• March 19, 2023 by Xing Lu and Karthik Devaprasad:
  Updated instance classes for sinSpeDX, mulStaDX, varSpeDX, and datCoiMulSpe.
  Updated connection statements to reflect change in input instance from TConIn to TOut in sinSpeDX, mulStaDX and varSpeDX.
  Updated comments and formatting for ease of understanding and readability.
• September 24, 2015 by Michael Wetter:
  Set start attributes in SimpleRoom so that the model translates when using the pedantic mode in Dymola 2016. This is for #426.
• December 22, 2014 by Michael Wetter:
  Removed Modelica.Fluid.System to address issue #311.
• September 13, 2013, by Michael Wetter:
  Changed control implementation of variable speed coil to use a proportional controller.
• January 11, 2012, by Michael Wetter:
  First implementation.