If you're running an Autoterm Air 4D (formerly Planar 44D) 4kW diesel heater in your van, campervan, or overland build, this adapter is the piece that bridges the heater's 96mm hot air outlet to standard 90mm ducting.

The Air 4D's larger 96mm outlet pushes out serious heat, but most ducting systems run at 90mm. Without this adapter, you're either improvising a connection or losing airflow. This part solves that cleanly — clip it onto the heater outlet, connect your 90mm duct, and you're done.

Why you need it

  
Designed specifically for the Autoterm Air 4D (4kW) — not a generic reducer
  
Converts the 96mm heater outlet to standard 90mm air ducting
  
Creates a secure, airtight connection to maintain heating efficiency
  
High-temperature resistant material rated for diesel heater output temperatures
  
Simple push-fit installation — no tools required
  
Keeps warm air moving efficiently through your distribution system


Compatibility
Fits the Autoterm Air 4D (also known as Planar 44D) 4kW diesel air heater. This is the outlet (hot air side) adapter. Part number ATR2-A9690-BK.

Works with
Pairs with 90mm flexible ducting hose, 90mm T-pieces, Y-adapters, and outlet vents for a complete heating distribution system.