Vent-Axia 476312 Lo-Carbon PoziDry Pro FD Positive Input Ventilation (PIV) Unit with Heater

The Vent-Axia 476312 Lo-Carbon PoziDry Pro FD Positive Input Ventilation (PIV) Unit with Heater is an advanced, energy-efficient whole-house ventilation system designed to help combat condensation, reduce mould growth and improve indoor air quality. Featuring an integrated 500W heater, a ceiling diffuser with integral fire damper and intelligent SmartSense™ controls, this loft-mounted PIV unit provides a practical ventilation solution for domestic properties, social housing and residential refurbishment projects.

Powered by Vent-Axia's Lo-Carbon DC motor technology, the PoziDry Pro FD delivers exceptionally quiet operation with adjustable airflow rates from 11 to 49 litres per second. Its integrated heater helps temper incoming air during colder conditions, while automatic loft temperature monitoring, G4 filtration and flexible mounting options support comfortable, efficient year-round ventilation.

Key Features

• Positive Input Ventilation (PIV): Continuously supplies fresh, filtered air to help reduce condensation, damp conditions and mould growth.
• Integrated 500W Heater: Automatically warms incoming air when required to improve comfort during colder weather.
• Integral Fire Damper: Supplied with a purpose-designed ceiling diffuser incorporating a fire damper.
• SmartSense™ Technology: Intelligent control platform provides automatic speed selection, straightforward commissioning and operational data logging.
• Adjustable Airflow: Fully configurable ventilation rates between 11 and 49 l/s to suit different property sizes.
• Energy-Efficient Lo-Carbon Motor: Electronically controlled DC motor technology helps minimise fan running costs.
• Ultra-Quiet Performance: Designed for discreet continuous operation with minimal disturbance to occupants.
• Automatic Temperature Monitoring: Adjusts ventilation according to loft temperature and operating conditions.
• Energy Recovery Mode: Increases airflow when excess heat is detected in the loft to help redistribute otherwise wasted heat.
• Summer Standby Mode: Reduces the introduction of excessively warm loft air when temperatures exceed the adjustable threshold.
• G4 Air Filtration: Supplied with G4 filters to help capture common airborne particles, including dust and pollen.
• Optional F7 Filter Upgrade: Enhanced PM2.5 filtration available for improved fine-particle removal.
• Flexible Loft Mounting: Supplied with anti-vibration joist mounting legs and a hanging kit.
• Smart Air™ Diffuser Technology: Designed to reduce air supply noise while improving airflow performance.
• Radon Operating Mode: Continuous ventilation setting available for properties requiring additional radon management measures.
• IPX2 Rated: Suitable for protected indoor installation.
• 5-Year Warranty: Manufacturer-backed warranty for long-term peace of mind.

Whole-House Condensation and Mould Control

The Vent-Axia PoziDry Pro FD uses positive input ventilation technology to address excessive indoor moisture, condensation and poor air circulation.

Installed within the loft, the unit draws in air, filters it and gently distributes it throughout the dwelling via a centrally positioned ceiling diffuser. The continuous supply of filtered air helps dilute and displace moisture-laden indoor air, encouraging stale air to escape through existing ventilation openings and natural leakage paths.

By improving air circulation and reducing excessive humidity, the system helps create a fresher, more comfortable living environment while reducing the conditions that encourage mould growth.

Integrated 500W Heater for Improved Comfort

Unlike standard non-heated PIV models, the Vent-Axia 476312 PoziDry Pro FD includes an integrated 500W heater designed to temper incoming air during colder weather.

The heater operates automatically when required, helping reduce the sensation of cold draughts associated with introducing fresh loft air into the home.

SmartSense™ controls allow the heater activation settings to be adjusted to suit property requirements and occupant preferences, supporting comfortable ventilation throughout the colder months.

Ceiling Diffuser with Integral Fire Damper

The PoziDry Pro FD is supplied with a purpose-designed ceiling diffuser incorporating an integral fire damper. This makes the unit suitable for installations where a fire-damper-equipped diffuser is specified, subject to the applicable fire safety design and installation requirements.

The discreet white circular diffuser features a low-profile design that blends into residential interiors. Its four-point contact fixing arrangement supports quick installation, while the diffuser design helps maintain a neat finish against uneven ceiling surfaces.

Smart Air™ technology is designed to reduce air supply noise and improve airflow performance by up to 10%. Clip-in blanking plates also allow installers to control the direction of air distribution within the property.

SmartSense™ Intelligent Control and Data Logging

The integrated SmartSense™ system simplifies installation and ongoing ventilation management by automatically selecting appropriate airflow settings based on the number of bedrooms within the property.

Installers can configure Trickle and Energy Recovery speeds, manually adjust airflow where necessary and lock the control interface to prevent unauthorised changes.

The system also records useful operational information, including:

• Total operating time at different fan speeds.
• Number of days the ventilation unit has been powered.
• Duration of integrated heater operation.
• Energy consumption information associated with heater activity.

This information supports maintenance, performance monitoring and effective management of residential ventilation systems.

Automatic Temperature Control and Energy Recovery

The Vent-Axia 476312 incorporates intelligent loft temperature monitoring to optimise ventilation performance and household comfort throughout the year.

• Trickle Mode: Maintains continuous, low-noise ventilation during normal operating conditions.
• Energy Recovery Mode: Increases airflow when excess heat is detected in the loft, helping redistribute heat that might otherwise escape through the roof.
• Summer Standby Mode: Activates when loft temperatures exceed the adjustable 27°C threshold, helping prevent excessively warm air from entering the home.
• Heater Operation: Uses the integrated 500W heater to temper incoming air during colder conditions.
• Radon Mode: Provides continuous airflow for properties where additional radon management ventilation is required.

Energy-Efficient and Ultra-Quiet Motor

The PoziDry Pro FD features an electronically controlled Lo-Carbon DC motor engineered for quiet, efficient and reliable continuous operation.

The motor incorporates long-life ball bearings and overload protection, while anti-vibration mounting components help minimise noise transmission through the building structure.

Designed for ambient operating temperatures between -25°C and +40°C, the unit provides dependable ventilation performance across a wide range of loft conditions.

G4 Filtration with Optional F7 Upgrade

The Vent-Axia PoziDry Pro FD is supplied with G4 filters designed to remove common airborne particles, including dust and pollen, before incoming air is distributed throughout the property.

For enhanced filtration, optional F7 filters are available to provide improved capture of PM2.5 fine particles, including certain smoke particles, diesel particulates and other airborne pollutants.

The replaceable filtration system supports straightforward maintenance and helps maintain effective air distribution.

Flexible Loft Installation

The Vent-Axia 476312 is designed for straightforward installation in domestic loft spaces, with both high-sided anti-vibration mounting legs and a hanging kit supplied as standard.

The mounting legs accommodate joist spacings between 300mm and 650mm, while clip-and-fit connections simplify assembly. An integrated carrying handle allows the unit to be transported more easily through loft hatches.

The supplied fire-damper-equipped diffuser is typically positioned above the stairwell, on a landing or within a central hallway to promote effective whole-house air circulation.

Technical Specifications

• Manufacturer: Vent-Axia
• Product Code: 476312
• Product Range: Lo-Carbon PoziDry Pro
• Model: PoziDry Pro FD with Heater
• Product Type: Positive Input Ventilation Unit with Heater
• Ventilation Type: Positive Input Ventilation (PIV)
• Installation Location: Loft Mounted
• Airflow Range: 11-49 l/s
• Integrated Heater: 500W
• Fire Damper: Integral to Ceiling Diffuser
• Motor Type: Electronically Controlled Lo-Carbon DC Motor
• Control Technology: SmartSense™
• Operating Modes: Trickle, Energy Recovery, Summer Standby and Radon
• Temperature Monitoring: Automatic Loft Temperature Sensor
• Summer Standby Threshold: 27°C (Adjustable)
• Standard Filtration: G4 (PM10)
• Optional Filtration: F7 (PM2.5)
• IP Rating: IPX2
• Mounting Options: Anti-Vibration Joist Legs and Hanging Kit
• Compatible Joist Spacing: 300-650mm
• Ceiling Diffuser: White Circular Diffuser with Integral Fire Damper
• Motor Protection: Overload Protection
• Motor Bearings: Long-Life Ball Bearings
• Ambient Operating Temperature: -25°C to +40°C
• Data Logging: Running Time, Fan Speeds, Days Powered and Heater Activity
• Primary Application: Domestic and Social Housing Ventilation
• Warranty: 5 Years

Applications

• Whole-house positive input ventilation systems
• Domestic condensation and mould prevention
• Social housing ventilation upgrades
• Residential refurbishment and renovation projects
• Loft-mounted ventilation installations requiring a fire damper
• Properties requiring tempered incoming ventilation air
• Energy-efficient continuous home ventilation
• Indoor air quality and moisture management

Additional Installation Information

Suitable internal airflow paths are important for effective whole-house ventilation. Where internal doors do not provide a 10mm undercut, an optional air replacement grille set may be required.

The optional two-piece telescopic grille set fits on either side of an internal door and is suitable for a minimum fixing thickness of 30mm. Grille dimensions are 454 x 90mm.

Note: The F7 filtration upgrade and air replacement grille set are optional accessories. Fire damper installation and suitability must be assessed against the property's fire safety requirements and the manufacturer's instructions.

Data Sheet

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Installation Guide

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