Verplas 200mm to 150mm Round Duct Reducer

Description

The Verplas VKC436V is a 200mm to 150mm white uPVC round duct reducer, providing a push-fit transition between 200mm and 150mm round duct runs. It is used wherever a 200mm duct connection — typically from a larger fan unit, cooker hood, or MVHR main spigot — needs to step down to a 150mm System 150 duct run. The one-piece uPVC body provides a clean, consistent transition without the airtightness risks of improvised adaptors or taped junctions.

200mm

Inlet Diameter

150mm

Outlet Diameter

Push-Fit

Tool-Free

White uPVC

Material

System 150

Output Compatible

Typical Use: The VKC436V is commonly used to connect a 200mm cooker hood or fan spigot to a 150mm System 150 duct run, or to interface a 200mm main spine duct to a 150mm branch distribution network.

Velocity Increase: Reducing from 200mm to 150mm increases airflow velocity in the smaller duct. Ensure the fan or MVHR unit can deliver required flow against the increased resistance of the 150mm section, and check that velocity remains within acceptable noise limits.

Key Features

200mm to 150mm Transition

Provides the correct one-piece manufacturer's reducer between 200mm and 150mm round duct — eliminating the need for improvised taped adaptors at this common interface.

White uPVC Construction

Made from white uPVC consistent with System 150 and wider Verplas round duct components for a clean, professional finish.

Push-Fit Connection

The 200mm female socket accepts 200mm male spigots; the 150mm male spigot inserts into System 150 female connectors — both push-fit and tool-free.

Cooker Hood & Fan Interfacing

Commonly used to adapt a 200mm cooker hood or inline fan spigot to the 150mm System 150 duct distribution network.

System 150 Compatible Output

The 150mm output spigot is directly compatible with all System 150 VKC-series fittings, connectors, and duct pipes.

Compact Single-Piece Body

The single-piece moulded body keeps the transition compact and airtight, avoiding the multiple-component solutions sometimes used for this interface.

Specifications

Verplas SKU	VKC436V
Inlet Diameter	200 mm (female socket)
Outlet Diameter	150 mm (male spigot)
Material	White uPVC
System Interface	200mm round duct to Verplas System 150

Frequently Asked Questions

Can this reducer be used in reverse (150mm to 200mm)?

Physically the fitting can be reversed, but the socket/spigot geometry is designed for the standard 200-to-150 direction. A reverse installation may not create a reliable airtight seal — use the reducer in its designed orientation.

Will reducing from 200mm to 150mm cause noise?

Diameter reduction increases air velocity and turbulence, which can increase duct noise. Keep the total system airflow within the rated limits for the 150mm duct, and consider a silencer (SIL150) downstream if noise is a concern.

What if my fan has a 150mm spigot but I want 200mm duct?

Use the reducer in reverse (as a 150mm to 200mm step-up) or source a dedicated 150mm-to-200mm expander fitting — these are available from duct accessory suppliers if required.

What is the difference between VKC436V and VKC437?

VKC436V reduces 200mm to 150mm. VKC437 reduces 150mm to 100mm. Both are Verplas System 150 range reducers for different diameter transitions.

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