BuildingSystems.Examples.Tutorial.SimpleHouse.SimpleHouse6

# .BuildingSystems.Examples.Tutorial.SimpleHouse.SimpleHouse6

Free cooling model

## Information

For this last exercise, we first increase the window size from 2 m2 to 6 m2.

We will add a ventilation model that allows to perform free cooling using outside air when solar irradiation heats up the room too much. The system consists of a fan, a damper, a controller with an air temperature setpoint between 23°C and 25°C, and a heat recovery unit with a constant effectiveness of 85%. The damper and fan have a nominal pressure drop/raise of 200 Pa. The heat recovery unit has a nominal pressure drop of 10 Pa at both sides. The nominal mass flow rate of the ventilation system is 0.1 kg/s.

#### Required models

- BuildingSystems.Fluid.Actuators.Dampers.Exponential
- BuildingSystems.Fluid.HeatExchangers.ConstantEffectiveness
- BuildingSystems.Fluid.Movers.Preconfigured.FlowControlled_dp
- BuildingSystems.Fluid.Sources.Boundary_pT
- Modelica.Blocks.Logical.Hysteresis
- Modelica.Blocks.Math.BooleanToReal

#### Connection instructions

Connect the components such that they exchange mass (and therefore also energy) with the `MixingVolume` representing the zone air. Add a `boundary_pT` to draw air from the environment. Enable its temperature input and connect it to the `TDryBul` variable in the weather data reader. Also reconsider the nominal mass flow rate parameter value in the `MixingVolume` given the flow rate information of the ventilation system. Finally, make sure that the fan is only active when the damper is open.

#### Reference result

The figures below show the results.

## Revisions

- September 4, 2023, by Jelger Jansen:
  First implementation.

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