info · 2026

How MERV-13 Air Filtration Works

Indoor air can carry the same pollen, dust mite debris and pet allergens that trigger hay fever symptoms. High-airflow air filtration pairs professional-grade MERV-13 filter media with quiet, efficient fans to pull allergens out of the air you breathe at home. This guide explains how that filtration reduces airborne pollen and allergens, how to size and place a unit, and what it costs to run.

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How Filtration Reduces Airborne Pollen and Allergens

Hay fever is triggered when airborne allergens reach your eyes, nose and airways. An air filtration unit works by continuously drawing room air through a dense pleated filter and returning cleaner air to the room. Each pass captures a share of the particles suspended in the air; run continuously, the unit steadily lowers the overall allergen load in the room.

The filter media used here is rated MERV-13, a professional-grade standard defined by ASHRAE. In independent testing, this media captures around 93% of fine airborne particles in a single pass. Common UK allergens sit comfortably within its effective range:

Airflow and Clean Air Delivery

Filtration efficiency only matters if enough air passes through the filter. What counts for allergy relief is how much clean air a unit delivers each hour. A large pleated filter has a very large surface area, which keeps resistance low and lets the fans move a high volume of air quietly.

Sizing the Unit to Your Room

For allergy relief, aim to filter the room's entire air volume several times per hour. To size a unit, multiply the room's floor area by its ceiling height to get the volume in cubic metres, then compare that with the unit's airflow.

If a room is very large or has high ceilings, run the unit on a higher setting or position it more centrally to maintain good air turnover.

Where to Place Your Air Purifier

Placement has a real effect on how well filtration reduces your symptoms:

Quiet, Low-Cost Continuous Running

The biggest advantage of efficient filtration is that you can leave it on. Constant, gentle filtration beats occasional bursts because allergens are removed as they enter the room rather than after they have built up.

Because it is so cheap and quiet to run, there is little reason to switch it off, which is exactly what keeps airborne allergen levels consistently low.

Tested and Verified Performance

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Frequently asked questions

Can an air purifier really help with hay fever?

Yes. By continuously drawing room air through MERV-13 media, a high-airflow unit captures around 93% of fine airborne particles per pass, steadily lowering the pollen, dust mite and pet allergen levels that trigger indoor symptoms - especially overnight in the bedroom.

What does MERV-13 mean?

MERV stands for Minimum Efficiency Reporting Value, an ASHRAE standard for filter performance. MERV-13 is a professional grade of filtration that captures fine particles including pollen, dust mite debris, pet dander and mould spores.

Where should I put the unit for best results?

Start in the bedroom for overnight relief, keep the air intakes and outlets clear of furniture, position it away from tight corners so air circulates, and keep windows closed when pollen counts are high.