Will Dehumidifiers Prevent Condensation

If you are having problems with condensation in your home and are worried about the potential risk of damp or mould developing, you may be tempted to use a dehumidifier.  While a dehumidifier could help to reduce the humidity in your home, it may not be sufficient to prevent condensation.

What causes condensation

The air in your home contains a substantial amount of moisture from daily activities including bathing, cooking, and drying clothes.  When this humid air meets a cold surface such as a window or wall, the water vapour is released by the air, and it forms droplets of water which appear as condensation.

While condensation on windows is not a major problem, if the moisture soaks into a porous surface such as a wall or woodwork, it can create a damp patch.  Damp can be damaging to the fabric of your home, causing wood to rot and plaster to crumble.  Even mild damp in walls can create large stains that require you to redecorate, while more serious problems may require expensive building work to be carried out.

Dampness creates the ideal environment for mould to grow, and you may notice this in the form of large dark blotches on your walls or ceiling.  Aside from being unsightly, mould spores are an allergen and can affect the health of people with respiratory problems or weakened immune systems.  Preventing condensation in your home reduces the risk of damp developing.

What is a dehumidifier

One way to reduce the amount of moisture in the air, and therefore the amount of condensation that you may encounter is using a dehumidifier.  There are different types of dehumidifiers and these work in different ways.

The simplest kind of dehumidifier works passively and uses a medium such as silica gel to absorb the moisture in the air.  They can be placed in areas with higher moisture levels, and as the air in the room passes through them, they will trap some of the water.

Electric dehumidifiers work differently.  They use a fan to actively draw the room’s air through a condenser which takes some of the moisture from the air.  They consume electricity and can be quite noisy.

All types of dehumidifiers trap the water and need to be emptied regularly to prevent water from standing in them for too long.

How effective are dehumidifiers

The biggest drawback of a dehumidifier is the lack of capacity.  Typically, a person will generate quite a lot of water vapour each day.  Bathing, cooking, drying clothes and even breathing all contribute to the amount of moisture in the air, and on average this means approximately 2.5 litres of water is released into the air per person.

Cheaper dehumidifiers may only have the capacity to hold 1 litre of water and can only cover a limited area.  Even more powerful dehumidifiers may only be able to cover a single room, meaning that they will only reduce condensation in their immediate area.  You may consider installing multiple units throughout your home, but this will use additional electricity and increase the cost.  A typical bath or shower may release as much as 1.7 litres of water into the air in the form of steam, and this will overwhelm the capacity of even the most powerful dehumidifier.

Improving ventilation is more effective

The most effective way to reduce condensation is through ventilation.  Installing modern extractor fans in your bathroom and kitchen will deal with the biggest sources of moisture quickly and prevent it from escaping into other rooms. 

If you are troubled with condensation away from your bathroom or kitchen, it may be better to have whole house ventilation installed.  Positive Input Ventilation systems such as the EnviroVent ATMOS draw fresh filtered air into your home which then displaces the stale and humid air that carries the water vapour in all your rooms.  PIV systems also have the benefit of creating a higher pressure of air inside the home which reduces the number of allergens such as pollen that can be drawn in during summer months.

Find out more

If you are struggling with condensation in your home or have noticed mould patches growing on your walls, we can help.  Book a free home survey with one of our local ventilation experts.  They will visit your home and identify the causes of condensation and provide you with advice about the best way to prevent it.  Enter your postcode below to find a specialist near you.