Why are allergies worse in the home during summer

Why are allergies worse in the home during summer

By Ruth MacEachern

Product Manager

On a warm summer day when the sun is shining, spending time outside is enjoyable for most people, but for Hayfever sufferers, pollen from grasses, trees and flowers can make summer a miserable time with painful allergy symptoms including blocked noses, streaming eyes, and sore throats.

Hayfever is one of the most common allergies and is estimated to affect more than 1 in 5 people in the UK.  For most sufferers, a simple daily antihistamine tablet can treat mild symptoms, however on days with a high pollen count, people with more severe Hayfever may not be able to find relief at all, and even staying at home with the windows closed will not prevent them having a reaction.

What Causes Hayfever?

Hayfever is a severe seasonal allergy caused by an immune system response to the inhalation of pollen grains released by plants.  People may be allergic to a specific type of pollen or may suffer a general reaction.

In the UK, the Hayfever season runs from May through until September with two main peaks in June and July when grasses and other plants are most likely to flower and release their pollen into the air. 

Grass pollens are the biggest cause of Hayfever simply because large fields of grasses can release their pollen at a similar time creating elevated levels in the air.  Hot and breezy days are the worst time for sufferers, as a light wind is more likely to carry the pollen into the face where it is inhaled or brought into contact with the eyes.

How does Pollen Get into a House?

Pollen grains are microscopic – even the largest grain of pollen in the world is only slightly larger than the thickness of a human hair.  Windborne pollens are typically between 15 and 35 microns in diameter (less than 1/30^th of a millimetre).  The tiny size of pollen grains means that they can easily enter a house through any gaps around doors or windows, or even through the vents in your loft.  Pollen can be carried into a building on people’s clothing or shoes, as well as in hair and on skin.

As pollen grains are discarded in the home, they mix in with other dust, but because they are so light, they can easily be picked up by airflow and inhaled.

Sufferers of Hayfever should avoid undressing in their bedroom and shower before bed to prevent pollen being transferred onto pillows and bedding where it can cause an allergic reaction during the night and make sleep more difficult.

Reducing the Amount of Pollen in a Home

Improving airflow through a building is the best way of preventing a build up of pollen.  Unfortunately for sufferers, simply opening a window is not a solution as this simply allows more pollen in. 

Positive Input Ventilation Systems (PIV) are the most effective way of preventing the build up of pollen in the home.  Air is drawn in from outside the building through filters that remove particles.  This air then circulates through the building and carries allergens out as it escapes through ventilation gaps.

A PIV system creates a higher air pressure inside the building which helps to prevent unfiltered air entering through other sources.

Ventilation will not prevent pollen from entering the house on clothing or hair but will significantly reduce the amount of pollen that is present.

Find out More

If Hayfever is stopping you enjoying your home during the summer, we can help.  Contact us today to speak to a local specialist who can arrange a free home survey and recommend a ventilation system that will help reduce allergens in your home as well as preventing condensation and damp that could lead to the development of other allergens such as mould.