What causes hay fever in the home

In the UK, the hay fever season runs from late spring until early autumn, with the peaks usually occurring during early June and early July when most grasses and weeds tend to shed their pollen.

Depending on the types of pollen that sufferers are allergic to, they may find that they suffer from symptoms at different times as different plants flower – some trees will shed pollen in spring, while some later flowering plants will be most active in early autumn. 

Outdoors, the weather has a big impact on how severe the pollen levels are, and the Met Office provide information about how high the pollen count is on any given day during the season.  The levels are highest during dry and breezy days when pollen can be carried more easily in the air, and lowest on wet days when it becomes trapped in standing water and does not move as freely.

Indoors, pollen is not affected by the weather as much.

Pollen build up in homes.

During the summer, many hay fever sufferers avoid opening windows to prevent pollen from getting into their homes.  Keeping windows closed will help to reduce the amount of pollen that is blown into a building, but the dust can still find its way in on clothing or through doorways and will still build up - albeit to a lower level.

Once pollen has found its way into a building it will become mixed with other dust particles and can become trapped in the building and may affect hay fever sufferers for longer periods of time than it would outdoors.

Reducing pollen in the home.

As pollen grains are tiny – even the largest pollen grain in the world (the pecan) is less than a tenth of a millimetre across – they are easily carried on even the lightest breeze, and as a result, can easily get into buildings through small gaps.

Keeping windows closed will help to reduce the amount of pollen that can enter a building, but it will not eradicate it entirely, and as previously mentioned, once indoors, the pollen will linger for some time as part of normal dust.

Vacuum cleaners can pick up pollen grains, but unless the unit has high quality filters installed, vacuuming can just spread pollen around the house and make things worse.

The most effective way of minimising the amount of pollen that gets into a house is with a ventilation system that includes filters that can remove pollen grains from the air.

Positive Input Ventilation Systems (PIV) work by drawing clean air into a building through a filtration system that removes small particles and then gently releasing that air throughout the building with vents in multiple rooms.  The PIV system has the added benefit of creating air flow through the whole of the house that gradually replaces any pollen laden air and keeps the overall levels low.

In addition to reducing the amount of pollen found in your home Positive Input Ventilation systems also help to lower the humidity which reduces condensation and prevents damp from forming – this has the benefit of reducing other allergens such as dust mites and mould spores that can have a similar effect to pollen on sufferers.

Find out more.

If you, or any of your household suffer from Hay Fever, and you want to reduce your exposure to pollen and enjoy your home during the summer, speak to one of our local ventilation specialists.  They will be able to conduct a free survey of your home and advise you about the best solution to meet your needs.