[NGTC] Night cooling

Function block NGTC activates the operating mode "Night cooling" based on the operating mode in the rooms and temperature values.

NGTC can be used to optimize energy consumption of air handling units. Rather than cooling rooms with air conditioning components, the rooms are cooled by the supply of cold outside air while unoccupied.

Functioning

Night cooling is switched on, when the following conditions are met:

  • Night cooling is enabled ([EnFnct] = 1).
  • The rooms are not occupied. Operating mode Economy or Protection is active: [OpModRIn] = Economy or Protection
  • The outside air temperature is not too low: [TOa] > [TOaLoLm].
  • The temperature difference for cooling is sufficiently high: [TR] - [TOa] > [SwiOnDT].
  • The temperature difference of room temperature and temperature setpoint is sufficiently high: [TR] > [SpTR] + [TRHys].

The night cooling switches off, if one of the following conditions is met:

  • Night cooling is disabled ([EnFnct] = 0).
  • The rooms are occupied. An operating mode other than Economy or Protection is active.
  • The outside air temperature is too low: [TOa] < [TOaLoLm] - [TOaHys].
  • The temperature difference for cooling is too low: [TR] - [TOa] < [SwiOffDT].
  • The room temperature is lower than the temperature setpoint: [TR] <= [SpTR].
Pins

Input

Description

Data type

Default value
Value range

EnFnct

Enable function

Enables the function.

Boolean

1

0 - The function is disabled.
1 - The function is enabled.

OpModRIn

Input for room operating mode

Integer

1: Inactive

1: Inactive
2: Protection
3: Economy
4: Pre-Comfort
5: Comfort
6: NightCool.
7: Purge
8: Stop
9: Start

NgtC

Night cooling

Activate night cooling without evaluating the conditions for temperature and room operating mode.

Boolean

0

0 - Normal more (evaluate temperatures and room operating mode).
1 - Night cooling is active, if [EnFnct] = 1.

TOa

Outside temperature

Real

20.0 [°C]
68.0 [°F]

-100.0…100.0 [°C]
-148.0…212.0 [°F]

TR

Room temperature

Measures the (reference) room temperature.

Real

20.0 [°C]
68.0 [°F]

0.0…50.0 [°C]
32.0…122.0 [°F]

SpTR

Room temperature setpoint

Real

20.0 [°C]
68.0 [°F]

5.0…35.0 [°C]
41.0…95.0 [°F]

TRHys

Room temperature hysteresis

Real

2.0 [K]
3.6 [°F]

0.0…20.0 [K]
0.0…36.0 [°F]

TOaLoLm

Low limit for outside air temperature

Real

9.0 [°C]
48.2 [°F]

0.0…35.0 [°C]
32.0…95.0 [°F]

TOaHys

Outside temperature for switching hysteresis

Real

3.0 [K]
5.4 [°F]

0.0…20.0 [K]
0.0…36.0 [°F]

SwiOnDT

Switch-on via temperature difference

Switch-on point if the temperature difference for cooling is sufficiently high.

Real

7.0 [K]
12.6 [°F]

0.0...20.0 [K]
0.0...36.0 [°F]

SwiOffDT

Switch-off via temperature difference

Switch-on point if the temperature difference for cooling is too low.

Real

5.0 [K]
9.0 [°F]

0.0...20.0 [K]
0.0...36.0 [°F]

 

Output

Description

Data type

Default value
Value range

OpModR

Operating mode for room

Integer

1: Inactive

1: Inactive
2: Protection
3: Economy
4: Pre-Comfort
5: Comfort
6: NightCool.
7: Purge
8: Stop
9: Start

EnNgtC

Enable night cooling

Boolean

0

0 - No
1 - Yes

SysUnits

System of units

Indicates the system of units used by the block.

Integer

1: International system of units (SI) (fallback)

1...5

1: International system of units (SI) (fallback)
2: International system of units (SI)
3: US system of units
4: Imperial system of units
5: Canadian system of units

ErrCode

Error code indication

Integer

0: No error

= 0 - No error
> 0 - Error codes