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Airflow Duplexvent DV400 Heat Recovery Unit

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Airflow Duplexvent DV400 Heat Recovery Unit
£1,338.00 including VAT Excluding VAT £1,115.00
Airflow Duplexvent DV400 Heat Recovery Unit


Airflow DV400 Heat Recovery Unit - 90000399

The Duplex-vent DV400 are highly efficient, side entry mechanical supply and extract ventilation units with heat recovery for an air capacity of up to 400 m3/hr.

The unit casing is made of high density EPP material which provides significant insulation, eliminates any thermal bridging.

The units include an easily removable, plastic heat exchanger which transfers warmth from the outgoing waste air stream into the incoming fresh air where its thermal efficiency exceeds 90%. At no point do the air-streams mix.

Having the latest, low energy EC fan technology, the DV400 comply with the ErP 2015 standards and are tested by TUV laboratories


Please note - You can purchase the heat recovery unit with or without the ductwork on this listing and the Unit and room ducting kits include the heat recovery unit


Key Features

  • Compact size (280mm height) provides space saving solutions
  • Suitable for properties of up to 240 m2
  • Paive House Approved
  • Over 90% thermal efficiency and low noise
  • Automatic, 100% summer bypass
  • Can be installed on the wall, under the ceiling or on the floor
  • Light weight enables one man installation
  • Simple manual switch as standard. Optional touch screen panel with advanced controls
  • Compliant to ErP 2015 standards
  • Complies with Building Regulations
  • 2 year warranty+

100% Automatic Bypass

The units are equipped with an automatic, 100% bypass which totally isolates the heat exchanger so that no air passes through it. This provides effective cooling in the summer season.

Mounting Positions

Unique to these side entry units is the ability to install the same unit at:

  • Wall / Floor - standing position
  • Ceiling - flat position (with inclination for drainage)
  • Floor - flat position (with inclination for drainage) This provides exceptional flexibility in product specification, installation and storage.


Simple control incorporates the following features:

  • Variable speed control 100% adjustable by the user
  • Automatic boost function increases air flow when needed (via volt-free contact or 0-10V sensor output)
  • Automatic frost protection reduces the supply ventilation rate for a certain period to prevent ice build-up within the heat recovery cell depending on the outside air temperature Automatic summer bypass provides free cooling in the summer season. Its motorised damper is triggered by the temperature sensor automatically
  • Heater control for frost heater and post-heater

Benefits of working with BPC Ventilation

  • Authorised Airflow distributors
  • In-House design service
  • In-House Technical support
  • Specialists in easy to install DIY systems
  • 1000s of products in stock in our own warehouse
  • Large showroom with working units on display
  • Installer network throughout the UK and Ireland
  • All systems comply to all the latest building control regulations 
  • 0% Finance available 
Technical Specification

Technical Specification

Technical Specification - Airflow DV400 Heat Recovery Unit - 90000399



Airflow DV400



Heat Recovery efficiency %


Digital Controller


Boost Switch control

Yes – Momentary

Interactive control


Humidity control


Airflow rate Max m3/h


Airflow rate @ 100Pa m3/h


Max dwelling size M2

240 (uk)

Max room extraction

Kitchen plus 5 extraction points

Specific fan power (lowest)


Dimensions W x H x D (mm)

850 x 280 x 820




Yes 2 x G4

Pre/ Post Heater


Summer Bypass 


Frost protection 


Sound level @3m db.(a)

36 - 46


Floor / ceiling / wall

Ductwork connections


Duct Diameter

4 x160mm

Condensate drain



2 year -1-year motors

Country of manufacture


Heat exchanger

Counterflow heat exchanger (PVC)

Available room sensors

Humidity, Timer, Pir





SAP Appendix Q


Fireplace mode


Alarm system integration


Passive House


ERP rating





Further Information

Further Information

How to install a Airflow DV400 using a radial ductwork system

Initial Design -

Airflow DV400 Wiring Requirements

  • 3amp switched spur beside unit
  • A optional humidity sensor or boost switch can be fitted- Allow for a 3 core 1mm cable from unit to surface mounted sensor in bathrooms
  • The unit is supplied with a three speed control switch as standard. The control switch is suitable for surface mounting and requires a 6 core alarm cable from unit to controller

Airflow DV400 Pre designed plan - Please follow the plan ensuring the correct number of pipes to each area - Please note the plan is only a guide and you may have to reroute pipe work differently and reposition valves to suit layout of rooms

No Plan - If a design is not possible due to renovation, Retrofit or properties with multiple obstacles simply follow the listed recommendations

We would recommend that you

  • Install 2 x pipes from the distribution box to the room air plenum if air flow requirement exceed 10 L/s or if length over 15 meters  
  • Install 2 x pipes from the distribution box to the air extract plenum in the main shower rooms and Kitchen
  • All other areas only require a single pipe from the distribution box to the room air plenum
  • Radial ductwork is suitable to be fitted below your loft insulation providing superior heat retention Insulate any ductwork or Manifold/ Distribution boxes with a minimum of 25mm thermal duct wrap that go above insulation in unheated attic spaces
  • Slim-line manifolds are suitable for installation to concrete ceilings and only require a 100mm service void
  • Position supply plenums approx. 500mm from corner of wall (avoid areas above beds and wardrobes)
  • Position extraction plenums to outside of showers and above kitchen sink (not cooker)
  • Only extract from a room with a open appliance (stove) if there is a supply with equal or higher airflow

Airflow DV400 Installation Guide

1st Fix

  1. Position unit proverbially on a wall or vertical timber frame with provided wall bracket
  2. Install wiring for controllers (see bottom of page for further details)
  3. Install condensation drain from unit to internal or external drain
  4. Install wall /Soffit vents or roof vents (Minimum 1.5 meter apart) Pipes are 125mm diamater
  5. Position distribution boxes in the chosen location (proverbially in a central location minimising duct lengths )
  6. Install silencer (if specified) to air supply distribution box
  7. Install solid rigid ductwork and between distribution boxes and MVHR unit, (If possible allow for insulated flexible ductwork for final connections of MVHR unit )
  8. Install radial pipe into the distribution box ,
  9. Cut to length and install pipe into ceiling plenum, (insure you install rubber seal onto pipe) secure pipe in place with fixing band or pipe clips

Warning! There can be either one or two pipes going from the distribution box to the plenum depending on the required airflow , Always check plan that will indicate 1 or 2 pipes Install insulated rigid or insulated flexible ductwork to external vents Seal all open pipes to prevent debris and moisture ingress


Airflow DV400 2nd fix

  1. Trim ceiling Plenums to height of plasterboard (Easier to do before plastering ceilings)
  2. Install air valves to plenums (slightly open valve by two turns)
  3. Install all controllers
  4. Check that condensation drain has been fitted
  5. Switch unit on and follow the set up procedures
  6. Check air flow rates and commission system

Airflow DV400 Commissioning

Fan speed of the ventilation unit is controlled in 8 steps at control panel

Adjustments of temperature, heater operation etc is carried out at the control panel