Dyson Big + Quiet Formaldehyde BP04 Purifying Fan Air Purifier - Prussian Blue/Gold

Dyson BP04 Purifier Big + Quiet Formaldehyde Purifying Fan – Prussian Blue/Gold (545814-01)

The Dyson BP04 Purifier Big + Quiet Formaldehyde Purifying Fan is designed for homes that need more than basic air cleaning. It combines powerful whole-room purification, detailed air quality sensing and quiet operation, making it suitable for larger living areas where consistent air quality really matters.

Engineered for Large Rooms up to 100m²

Most air purifiers struggle to move air effectively across bigger spaces. The BP04 is built differently. It projects purified air over 10 metres, helping circulate clean air evenly throughout open-plan rooms.

This means you’re not just cleaning the air near the machine—you’re improving air quality across the entire space, whether it's a large lounge, kitchen-diner or studio layout.

Advanced 3-Stage Filtration – What It Actually Does

The filtration system works in layers, each targeting a different type of pollutant:

• HEPA H13 filter – captures ultra-fine particles like dust, pollen, pet dander and even bacteria
• Activated carbon filter – removes gases, smoke and household odours (like cooking smells)
• Catalytic filter – continuously breaks down formaldehyde rather than simply trapping it

Together, these filters handle both visible and invisible pollutants, from everyday dust to airborne chemicals released by furniture or cleaning products.

Detects and Destroys Formaldehyde Continuously

Formaldehyde is commonly released from materials like wood furniture, fabrics and paints. It’s also one of the hardest pollutants to deal with.

The BP04 uses a solid-state sensor that detects extremely small formaldehyde particles (much smaller than standard HEPA filtration can capture). Once detected, the catalytic filter breaks it down into harmless elements—and importantly, it keeps doing this over time without needing replacement.

K-Carbon Filter – Designed for Urban Living

If you live near traffic or in a built-up area, nitrogen dioxide (NO₂) can be a concern indoors as well as outdoors.

The K-Carbon filter is treated with potassium carbonate, allowing it to absorb significantly more NO₂ than standard carbon filters. In practical terms, this helps reduce exposure to pollution that can enter your home from outside air.

Real-Time Air Quality Monitoring You Can Understand

Inside the purifier is a group of sensors that track:

• Particulate matter (PM2.5 / PM10)
• Volatile organic compounds (VOCs)
• Nitrogen dioxide (NO₂)
• Formaldehyde
• Carbon dioxide (CO₂)

The system checks air quality constantly and shows live updates on the LCD screen or in the MyDyson™ app.

Rather than just running blindly, the machine adjusts itself based on what it detects—so you always know what’s happening in your home.

Auto Mode – Works in the Background

Auto mode is designed for everyday convenience. When pollution levels rise (for example, during cooking or cleaning), the purifier increases its power automatically.

Once the air is clean again, it reduces activity to save energy and keep noise levels low. You don’t need to constantly adjust settings—it manages itself.

Quiet Operation – Even at High Power

Large purifiers are often noisy, especially when working hard. Dyson has focused on acoustic engineering here, reducing turbulence and motor noise.

• Runs quietly during normal use
• Night mode lowers noise even further
• Sleep timer lets you run it overnight without disturbance

This makes it suitable for living rooms, bedrooms or home offices where constant noise would be distracting.

Cooling Fan Function – More Than Just Purification

The BP04 isn’t only for air quality—it also helps with comfort.

It delivers a strong stream of purified air, which can be adjusted depending on your preference:

• Set airflow angles (0°, 25° or 50°)
• Use Breeze mode for a more natural, varied airflow
• Helps cool you during warmer weather

So instead of needing a separate fan, this works as a 2-in-1 solution.

Full App & Smart Home Control

Using the MyDyson™ app, you can:

• Monitor air quality remotely
• Adjust fan speed and modes
• Set timers and schedules
• Track filter life
• Get alerts when air quality changes

It also works with compatible voice assistants, so you can control it hands-free.

CO₂ Monitoring & Alerts

The BP04 doesn’t just track particles and gases—it also monitors carbon dioxide levels.

If CO₂ levels rise (which can happen in poorly ventilated rooms), the system alerts you. This is useful for maintaining a fresher, more comfortable indoor environment, especially in sealed or busy living spaces.

Long-Lasting Filter System

Unlike many purifiers that require frequent replacements, the HEPA filter is designed to last up to 11 years under normal use.

This reduces ongoing maintenance costs and makes the product more practical over time.

Easy to Move, Easy to Live With

Despite its size and power, the BP04 is designed for everyday use:

• Hidden wheels make it easy to move between rooms
• Stable, well-balanced design
• Premium Prussian Blue/Gold finish fits modern interiors

Key Features Summary

• Covers large spaces up to 100m²
• Projects air over 10 metres for even purification
• HEPA H13 + Carbon + Catalytic filtration
• Destroys formaldehyde continuously
• K-Carbon filter absorbs more NO₂
• Real-time air quality sensing with LCD display
• CO₂ monitoring with alerts
• Quiet operation with Night mode
• Cooling fan with adjustable airflow
• App and voice control via MyDyson™
• Long-life filter (up to 11 years)

A More Complete Air Care Solution

The Dyson BP04 goes beyond basic filtration. It actively monitors, reacts and improves your indoor air—while staying quiet and easy to use. For larger homes or open-plan spaces, it offers a more consistent and intelligent approach to air quality.

General Specifications

Dimensions & Build (Purifier BigQuiet Formaldehyde)

In the Box

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