Low Temperature Radiant Electric
The Low Temperature Radiant Electric equipment is a zone level piece of equipment that is intended to model any “radiant system” where electric resistance heating is used on a surface (wall, ceiling, or floor).
A Ceiling Radiant Panel must be assigned to a zone that contains rooms with radiant layers in their ceiling construction. An In Floor Radiant Panel must be assigned to a zone that contains rooms with radiant layers in their floor construction.
The heating is controlled by varying the electrical power supplied to the unit. This model covers either a radiant panel system or wires embedded in entire walls, floors, or ceilings. This equipment group should not be used to simulate High Temperature Radiant electric or gas radiant heaters.
Nominal Heating Capacity
|
Default: Autosize
|
|
Typical Range: Autosize
|
|
Min Max: N/A
|
|
Units: Btuh, Mbh, tons, tons/ft2, Btuh/ft2, W, W/ft2, W/m2, kW, % of Htg capacity
|
This field specifies the maximum amount of electric energy rate (electric power) converted into heat. This input field is auto sizable. The controls for the radiant system will vary the amount of power supplied to the surface between zero input and the maximum power specified in this field.
Temperature Control
Control type
|
Default: Mean Air Temperature
|
|
Typical N/A
|
|
Min Max: N/A
|
|
Units: N/A
|
This Control Type field specifies how the user wishes to control the Heating Range of the low temperature radiant electric system. The temperature specified in the Constant setpoint Temperature field can refer to one of the following different temperatures selected in the Control Type field:• MeanAirTemperature
-
Mean Air Temperature
-
Mean Radiant Temperature
-
Operative Temperature
-
Outdoor DryBulb Temperature
-
Outdoor WetBulb Temperature
Note: Operative temperature for radiant system controls is the average of Mean Air Temperature and Mean Radiant Temperature..
Heating Range
|
Default: 3.6 Delta °F
|
|
Typical Range: N/A
|
|
Min Max: x > 0.5 Delta °C
|
|
Units: Delta °F, Delta °C, Delta °R, Delta °K
|
This field specifies the range of temperature over which the radiant system throttles through the electric resistance from zero heat input up to the maximum specified in the Nominal Heating Capacity field. The Heating Range parameter is used in conjunction with the Constant Setpoint Temperature Type to define the response of the system to various zone conditions. The field Constant Setpoint Temperature specifies the temperature where the power input to the system is at half of the maximum power input. For example, if the Constant Setpoint Temperature is currently 15°C and the Heating Range is 2°C, the electrical power supplied to the radiant system will be zero when the controlling temperature is at or above 16°C and the maximum power input when the controlling temperature is at or below 14°C. This represents a throttling range of 2°C around the setpoint of 15°C. In between 14°C and 16°C, the power input to the radiant system is varied linearly.
Setpoint Temperature Type
|
Default: Constant
|
|
Typical Range: N/A
|
|
Min Max: Constant, Variable
|
|
Units: N/A
|
This field specifies the type of heating setpoint for the radiant system. Used in conjunction with the Heating Range field, it will define whether or not the system is running and the current power input to the radiant surface. Power input to the system is varied linearly around the setpoint temperature based on the Heating Range and the maximum electrical power parameters. The field Setpoint Temperature specifies the temperature where the power input to the system is at half of the maximum power input. For example, if the Constant Setpoint Temperature is currently 15°C and the Heating Range is 2°C, the electrical power supplied to the radiant system will be zero when the controlling temperature is at or above 16°C and the maximum power input when the controlling temperature is at or below 14°C. This represents a heating range of 2°C around the setpoint of 15°C. In between 14°C and 16°C, the power input to the radiant system is varied linearly.
Constant/Variable Setpoint Temperature
|
Default: 55°F (constant)/Null (variable)
|
|
Typical Range: N/A
|
|
Min Max: N/A
|
|
Units: ºF, °C
|
This field specifies the heating setpoint for the radiant system depending on the Setpoint Temperature type. For a Constant type, the user should enter a Constant Setpoint Temperature. For a Variable type, the user can select a setpoint schedule from the menu.