MVHR Fresh Air Ventilation

What Is the Big White Box in My Hallway Cupboard? 

The Truth About MVHR Systems in Central London Apartments 

If you live in a modern London flat, you’ve probably opened your hallway cupboard and wondered: “What’s this big white box taking up all my storage space?” 

It’s called an MVHR system (Mechanical Ventilation with Heat Recovery), and it plays a critical role in improving your indoor air — especially in central London, where pollution levels are among the highest in the UK. 

Let’s unpack what it is, why it matters, and what you need to do to keep it working properly.

Why Do London Apartments Have MVHR Systems? 

MVHR systems are now standard in high-end, airtight developments where windows are rarely opened. They: 

• Supply filtered fresh air to living and sleeping spaces 

• Extract stale, humid air from kitchens and bathrooms 

• Recover heat from outgoing air to maintain energy efficiency 

In London, this is vital — because when you close your windows to keep noise and pollution out, you also trap moisture and stale air inside. 

Why Is London Air Quality a Concern Indoors? 

According to the Greater London Authority, road traffic remains the largest source of air pollution in London. Pollutants such as PM2.5, nitrogen dioxide, and carbon particles are common — and these can make their way into your flat without proper filtration. 

MVHR systems help mitigate this by using filters that clean the air before it enters your home. 

Does My Floor Level Affect Filter Maintenance? 

Yes — and this is one of the most important but least understood factors. 

• If you live below the 25th floor, your apartment is closer to street-level pollution. Your filters will clog up more quickly and need more frequent servicing. 

• If you live higher up, there’s less direct exposure to diesel fumes and construction dust. Your filters may last longer but still require attention. 

At Maintain My Home, we adjust your filter schedule based on your floor level and local air conditions. 

Do I Need to Upgrade My Filters? 

Most systems are fitted with basic G3 or G4 filters — which capture large particles but not fine pollution, pollen or allergens. 

We regularly upgrade our clients to: 

• F7-grade filters for better particulate removal 

• HEPA filters for allergy and asthma sufferers 

• Activated carbon filters for odour and chemical absorption 

This is especially important if you live near busy roads, have children, pets, or suffer from respiratory issues. 

Do MVHRs Do Anything Else? 

Yes — more advanced MVHR systems monitor indoor humidity levels and automatically extract moisture when they detect activities like showering or cooking. 

This helps: 

• Prevent condensation and mould 

• Protect timber floors, cabinetry, and soft finishes 

• Maintain a stable environment for artwork and furnishings 

FAQ: MVHR Systems in London Apartments 

What does an MVHR unit actually do? It replaces stale air with fresh, filtered air while recovering heat from the outgoing air. It’s designed to ventilate without opening windows. 

Why is it located in my hallway cupboard? This central location provides access to all ductwork and allows for regular servicing. It’s also a quieter, hidden option. 

How often should MVHR filters be cleaned or replaced? It varies based on your location and apartment height. In central London, lower-floor apartments may require filter checks every 3–4 months. Higher floors may stretch to 6–12 months. 

Can I install better filters in my system? Yes — many residents upgrade to F7 or HEPA filters for better protection against pollution and allergens. 

Do MVHR systems control humidity? Higher-end models do. They monitor moisture levels and extract humidity automatically, which is excellent for protecting finishes and preventing condensation. 

Final Thoughts 

The “big white box” in your cupboard is far more than just a bulky appliance. In a city like London, it’s your home’s first line of defence against pollution, moisture, and airborne allergens. 

But it can’t do its job without regular care. 

Worried your MVHR isn’t protecting your home as it should? 

Call our team on 02 0369 50901 or email fixme@maintainmyhome.uk. 

The only maintenance company exclusively focussed on luxury London apartments