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In this instalment of A-Z of Atlantis Damp Proofing… V is for ventilation to stop condensation.

Ventilation simply refers to the movement of air between the inside and outside of a building. It is essential for indoor air quality as you need a movement of air to dilute and disperse the pollutants and contaminants that otherwise build up inside every home.

Good ventilation can also help prevent damp taking hold in your home. Condensation is a common problem in many UK homes and is caused when moist, warm air comes into contact with a colder surface such as a window or outside wall. This can lead to damp and black mould, which can be detrimental to your health and be damaging to your home. Ventilation can help by dispersing and getting rid of the damp air before condensation can occur.

You may have seen our other blogs on Quality of Internal Air and Condensation. Here, we take a closer look at the different types of ventilation systems available and give you some hints on tips in reducing condensation in your home.

The Christmas period can often be a busy time. You have presents to buy, food to prepare, parties to host and family to entertain. One thing you don’t want to be worrying about is condensation.

At Christmas time your motto may be ‘the more the merrier’. Unfortunately the more people you have in your home, the more moisture you produce and the more likely it is you will see the signs of condensation.

How can I reduce condensation?

Living Room

  • Position heaters under the windows and place curtains a necessary distance away from the glass to allow free movement of warm air.
  • Try to open windows for at least a few minutes each day to permit air changes.
  • Arrange furniture away from the surrounding walls so that air can move around the property.


  • Try to keep internal doors shut and keep a window open.
  • Install an extractor fan to rid moisture laden air.
  • Put lids on saucepans while you’re cooking to reduce the amount of steam.
  • If you use a vented tumble drier, make sure it’s properly vented to an open window or through an outside wall.


  • Following bathing or a shower, shut the door and prop the window to prevent moisture laden air from finding its way around the rest of the house.
  • Install a humastatc fan


  • Leave trickle vents (slotted vents in the window frames) open when rooms are occupied – even in the winter when your heating is on. These vents provide constant ventilation which removes water vapour.
  • Avoid drying laundry on a clothes airer or radiator. If you need to dry clothes indoors, open the window and close the door of the room where the clothes are drying, so that moisture can escape outside rather than circulate around your home.
  • If you can, put free-standing wardrobes and other furniture against internal walls, leaving a gap between the wall and the furniture so that air can circulate around the room.

You will see a common theme to tackle condensation in your home. That is ventilation.

What types of ventilation are there?

he most basic type of ventilation is natural ventilation. This is achieved through fixed vents, air breaks, small gaps in the building materials, or just from opening windows and doors. This does not always provide adequate ventilation, however, especially in modern, energy-efficient buildings that are becoming increasingly airtight.

Extractor fans are good for removing stale, dirty or damp air from individual rooms such as kitchens and bathrooms. To improve the indoor air quality throughout the building, however, you will need to look at whole-house ventilation.

What is a passifyer ventilation to stop condensation?

What is standard ventilation to stop condensation?

What is a whole-house ventilation to stop condensation?

As the name suggests, whole-house ventilation gently moves air throughout the whole building.

There are a number of ways we achieve this. One of these ways is through Positive Input Ventilation (PIV) which draws air from outside, usually through a unit installed in the loft or roof space. It is filtered for impurities, and the extra pressure creates a constant gentle airflow through the property. Negative pressure ventilation pumps air like extractor fans, but not as common for whole-house systems.

This can help improve your energy efficiency at the same time as it improves your indoor air quality.

Positive Input Ventilation systems are ideal for curing mould & condensation, reducing radon, and air filtration. Additionally, a single system ducted to a central area covers your whole property. There are loft and wall mounted options if you live in a house or an apartment.

What is sub-floor void ventilation

We wouldn’t be doing our job if we didn’t also tell you about potential condensation under your floor boards. We call this the sub floor void.