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In this chapter we will provide an overview of the different controllers available in Polysun and their use and operation.

The following controllers are currently implemented in Polysun:

  • Solar loop controller
  • Variable speed pump controller
  • Auxiliary heating controller
  • Mixing valve controller
  • Heating circuit controller
  • Temperature controller with AND/OR Operation 
  • Flow rate controller
  • Irradiance controller

Controller functions are basically editable at all user levels. Only the Designer level enables the user to individually integrate controllers within hydraulic schemes. Light level users will not be able to edit control outputs. Professional level users are able to edit the control parameters, but not the controller type.

Note: Controllers employed in Polysun templates are defined as they are normally used in practice. The pre-defined parameter settings do not in any way claim to ensure enhanced solar yields. 


Solar loop controller

The solar loop can be controlled in 4 different ways:

  1. Fixed flow rate
  2. Specific flow rate per collector field (in l/h per m² of aperture area)
  3. Matched Flow
  4. Pressure drop according to the pump characteristics

Variable speed pump controller

Controls the flow rate of the primary pump so that the secondary side reaches a certain temperature.

Auxiliary heating controller

Can be used for internal electric resistance heaters and external boilers. The two output signals are equal and digital. Therefore, in certain cases, the controller can also be used for pumps.

Mixing valve controller

Generates an analog output signal and mixes two inlet temperatures to reach the requested value. The hotter connection is connected horizontally on the left side of the ‘x’ symbol. The colder connection is connected vertically by the ‘x’ symbol.

Heating circuit controller

Can be used to control the pump of the heating circuit.

Temperature controller with AND/OR operation

Generates a digital output signal and is best applied to switching valves. One output signal is calculated based on two temperature levels, which can be set freely. It can also be used as a controller for heat generators and pumps. Various reference temperatures can be linked logically with AND/OR operations.

Flow rate controller

Measures a flow rate and passes it on as a pump setting. The flow rate controller provides a digital output signal and thus can also be used to turn a heat generator on and off.

Irradiance controller

Provides a digital output signal based on different radiation intensity values.

Programmable controller

Freely programmable with spreadsheet-linke functions. Dynamic control of any components (Polysun Designer and above).

Plugin controller

External implementation of the control logic (e.g. in Python, Java, Matlab, …) via a plugin (Polysun Research or Premium).