Login

Privacy Policy (GDPR)
Authorization
Not registered yet? Take advantages of registration:
Products saving in a binding to the projects
Product consultation from our experts - Online
Registration
Signup
By using this form, you confirm that you have read the site terms of use Terms of use and completely accept the terms of use

VENTS NKD A21 V.2 series

VENTS NKD A21 V.2 series
Duct heater for supply air post-heating with external control
Model features
  • For round ducts
  • Ventilation accessories
  • Description
  • Modifications
  • Downloads
  • Designation key
  • Compatibility table
  • Electric heater power selection diagram
Description
Description
APPLICATION  
  • The heater is designed for integration into a ventilation system and joint operation with an air handling unit equipped with a control system used to switch on the heater and control its operation.
  • The heater maintains the supply duct air temperature at a point set by the unit controller.
DESIGN  
  • The casing, the junction box and the heater cover are made of galvanized steel with the heating elements in stainless steel.
  • The heater casing is additionally heat-insulated with 20 mm non-flammable mineral wool layer.
  • The heaters are equipped with rubber seals for airtight connection to the air ducts.
  • NKD A21 V.2 duct heaters are equipped with a factory-wired power cable and a control cable, and also have a duct temperature sensor that is connected to the ventilation unit.
  • Temperature control is carried out smoothly by the ventilation unit controller due to the PWM signal in cycles of 10 seconds.
  • Load commutation is carried out by the semiconductor device (triac).
  • The heaters are equipped with overheat thermostats:
    ⏵main overheat protection with automatic reset at +50 °C
    ⏵emergency overheat protection with manual reset at +90 °C
MOUNTING  
  • The heater design ensures its mounting on the round ducts in any position by means of clamps (included in delivery).
  • The air flow direction shall match the direction of the arrow on the heater casing.
  • In case of horizontal mounting the control box must be installed with the cover upwards.
  • Swivel range from the normal position up to max. 90°.
  • Do not install the control box with the cover downwards.
Downloads
Downloads
Select document type
  • Advertising and printing products
  • Certificates
  • Technical documentation
Name
"NKD A21 V.2" product description 10-2021 (pdf 481.66Kb)
"NKD A21 V.2" user's manual 09-2021 (V249EN-01) (pdf 1.37Mb)
Download high quality image "NKD A21 V.2" (psd 2.25Mb)
Download image "NKD A21 V.2" for your website (png 476.03Kb)
Designation key
Designation key
Series Connected air duct diameter [mm] - Heater power [kW] - Phases Options
NKD 125; 150; 160; 200; 250; 315 0.6; 0.8; 1.2; 1.7; 2.0; 3.0 1: single-phase A21 V.2: compatible with A21 automation, without a DB-9M connector
Compatibility table
Compatibility table
Heater model (connected air duct diameter)  
NKD 125 A21 V.2 VUT/VUE VB EC A21
NKD 150 A21 V.2 VUT/VUE VB EC A21
NKD 160 A21 V.2 VUT/VUE VB EC A21
NKD 200 A21 V.2 VUT/VUE VB EC A21
NKD 250 А21 V.2 VUT/VUE VB EC A21
NKD 315 A21 V.2 AirVents with a 315 mm spigot and an A21 automation without a DB-9M connector
Electric heater power selection diagram
Electric heater power selection diagram

The NKD A21 V.2 heater parameters calculation example:

  • It is necessary to select a heater for supply air post-heating to a temperature of +24 °C, provided the temperature downstream of the heat exchanger is +17 °C. Therefore, it is essential to increase temperature by 7 °C. The ventilation system incorporates the VUT 350 VB EC A21 air handling unit. The rated air flow is 400 m³/h. Determine the intersection of the post-heating temperature line (+7 °C) and the rated air flow line (400 m³/h).
  • In this case the 1200 W heater capacity provides necessary post-heating (+7 °C). The heater NKD 160-1,2-1 A21 V.2 with the diameter matching the spigot diameter of the VUT 350 VB EC A21 air handling unit is a suitable model.
Share your opinion

Questionnaire
Where have you learned about us?