Buildings.Fluid.HeatExchangers.ThermalWheels.Data

Performance data for thermal wheels

Information

This package contains performance data sets for thermal wheels.

Extends from Modelica.Icons.MaterialPropertiesPackage (Icon for package containing property classes).

Package Content

Name	Description
ASHRAE	ASHRAE data record for variable-speed thermal wheels
Generic	Generic data record for thermal wheels
Characteristics	Functions for wheel characteristics

Buildings.Fluid.HeatExchangers.ThermalWheels.Data.ASHRAE

ASHRAE data record for variable-speed thermal wheels

Information

ASHRAE performance dataset for the variable-speed wheel model.

It is developed based on Figure 7 in ASHRAE (2024). However, the original data set was extrapolated to cover lower values of speed ratio, i.e. <= 0.2, by setting the heat exchange effectiveness corrections to 0 when the speed ratio is 0.

References

ASHRAE (2024). Chapter 26, Air-to-Air Energy Recovery Equipment, ASHRAE Handbook—HVAC Systems and Equipment.

Extends from Buildings.Fluid.HeatExchangers.ThermalWheels.Data.Generic (Generic data record for thermal wheels).

Contents

Modelica definition

Buildings.Fluid.HeatExchangers.ThermalWheels.Data.Generic

Generic data record for thermal wheels

Information

Record containing performance-related parameters for thermal wheels.

It is used as a template of performance data for the thermal wheel models in Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses.

The record contains the parameters, including the nominal mass flow rates, nominal pressure drops, the heat exchanger effectiveness at part load (75% of the nominal supply flow rate) and at nominal conditions, and the wheel power consumption at the nominal wheel speed.

For the variable-speed thermal wheel (have_varSpe=true), the record also includes the following datasets:

• motor percent full-load efficiency versus wheel speed ratio,
• sensible heat exchange effectiveness corrections versus wheel speed ratio,
• latent heat exchange effectiveness corrections versus wheel speed ratio.

Note the following:

• The heat exchange effectiveness corrections versus wheel speed ratio are correction factors that are multiplied with the heat exchange effectiveness that the wheel has a full rotational speed.
• When have_latHEX=true, the dataset of the latent heat exchange effectiveness corrections versus wheel speed ratio is enabled,
• When use_defaultMotorEfficiencyCurve=true, the motor percent full-load efficiency versus wheel speed ratio is disabled, and the default curve (see Buildings.Fluid.Movers.BaseClasses.Characteristics.motorEfficiencyCurve) is used for calculations.

Extends from Modelica.Icons.Record (Icon for records).

Contents

Modelica definition