Why Trickle Vents Can Cause Condensation and Mould Growth

Imagine a tiny window you’re supposed to leave open all the time to let fresh air in. That’s a trickle vent. They were designed to stop moisture building up in our homes, which causes damp and mould. But in reality, they often make the problem worse. Here’s why.

1. People Just Close Them

This is the biggest reason. Think about it: would you leave a window open all winter? Of course not! You’d be cold and your heating bill would be huge. That’s exactly how people see trickle vents – as a tiny hole letting the cold in and the heat out. So, they shut them. The moment they’re closed, all the moisture from cooking, showering, and drying clothes gets trapped inside with nowhere to go. This moisture then settles on cold walls and windows as condensation, which is the perfect start for mould.

2. They Don’t Let in Enough Air (Even When Open)

Even if you are really good and leave your trickle vents open, they often aren’t powerful enough. Modern houses are built to be very sealed to save energy, which is great for bills but bad for air. A typical family produces buckets of moisture every day just from everyday life. A single trickle vent can’t deal with all that. It’s like trying to empty a flooded bathroom with a teaspoon.

3. They Can Create Cold, Damp Spots

Here’s the really ironic part. The small amount of cold air that does come through the vent can make the wall and window frame around it very cold. When the warm, moist air from your room touches this cold spot, it immediately turns into water droplets (condensation). So, the very device meant to stop damp can actually create a perfect little damp patch for mould to start growing right next to it.

What’s the Better Solution?

The problem with trickle vents is that they rely on you remembering to leave them open. A much smarter solution is a ventilation system that works automatically, all the time.

These are quiet fans, often installed in kitchens and bathrooms, that constantly and gently pull the damp, stale air out of your house. Because they run slowly, they don’t cause draughts or waste heat. They just get on with the job, making sure moisture is removed before it can cause any problems.

Some advanced systems even have a heat recovery feature. This means they cleverly take the heat from the stale air being pushed out and use it to warm up the fresh air coming in. So, you get fresh, healthy air without a huge heating bill.

Stop relying on draughty holes in the wall; discover how a modern ventilation system can automatically protect your home from damp and mould.