Does Using the Heating Help Reduce Condensation

This winter, people around the UK have been doing their best to save energy to reduce their bills, and one of the easiest ways of doing this has been to turn their thermostats down and heat rooms to a slightly lower temperature.  A temperature of 18^oC rather than 20^oC might not feel much different, but it can impact how likely your home is to suffer from condensation.

Why temperature affects condensation

Condensation is formed when warm air comes into contact with a cold surface such as a wall or window.  The atmosphere in your home is quite humid and carries significant amounts of water vapour.  At colder temperatures, the air can hold less moisture, and as the water vapour is released, it forms into tiny droplets, which we see as condensation.

We tend to notice condensation most in the morning.  This is because temperatures in our homes typically drop overnight while we are asleep and don’t use our heating.  As the house is coldest first thing in the morning, that is the peak of condensation.  As temperatures rise, some of the water droplets will evaporate and be picked up by the air allowing the condensation to disappear.

How much moisture does the air hold?

Air can hold a surprising amount of water, increasing as the temperature rises.

At 0^oC, the air is quite dry and holds a maximum of just under 5g of water vapour per cubic metre.  Increasing the temperature to room temperature, or 20^oC, the air will hold more than three times as much moisture – just over 17g.  In a typical 16m² bedroom, the difference in the amount of water in the air is about 360ml – slightly more liquid than you would find in a can of coke!

Even a tiny difference in the average temperature in your home can lead to a big difference in the amount of condensation that will form.

Why heating use affects condensation

Over the past winter, you may have seen more condensation in your home than usual, and the most likely reason for this is that you have used your heating a bit less than average but haven’t changed other behaviours.

Every day, each person in your home will contribute to the air's moisture.  Cooking, bathing, drying clothes and even breathing all release water vapour into the air.  On average, each person in a household will generate about 2.5kg of water vapour.  This builds up day and night; if the temperature is lower, more will condense on walls and windows.

If you are concerned about using heating too much and increasing your energy bills, there are some simple changes that you can make to reduce condensation:

Cooking with pan lids on and the kitchen door closed releases less steam into the air and prevents it from escaping into the rest of your home

Drying clothes outdoors where possible and not putting towels on radiators reduces the moisture they release indoors.

Setting your water temperature slightly lower can reduce the amount of steam from showers and baths.

You can read more tips to reduce condensation here>>

The most effective way to stop condensation and prevent it from developing into damp and mould is to improve your home ventilation.  Extractor fans in bathrooms and kitchens cost very little to run and are very effective at removing moist air at their source.  Some modern bathroom extractor fans, such as the EnviroVent HeatSava, incorporate a heat exchanger into their design.  This captures the warmth from the air that is being extracted and uses it to heat incoming air, which can make your home more energy efficient.

Whole house ventilation systems such as ATMOS – a positive input ventilation system (PIV) use a central unit to draw fresh air into your home from the outdoors.  This is then gently released throughout the building to displace the stale and humid air, preventing condensation throughout your house.  PIV systems help to even out the temperature throughout your home, reducing energy use.

Get Help to Stop Condensation

Condensation can cause damp and mould to form, which may lead to expensive repair bills and health risks for people with weaker immune systems. Our local ventilation specialists can visit your home and conduct a free home survey to identify the causes of damp.  They can advise you on the best way to stop condensation for good.  Simply enter your postcode into the form below to find a ventilation expert near you.