Blog 2: Beneath the Surface; Underfloor Expertise for a Smart Retrofit Solution
Timing of ventilation is as important as the air circulated
Why the timing of ventilation is as important as the amount of air circulated
When people think about ventilation, the focus is often on volume: more vents, more air changes, more flow. These are the traditional benchmarks of whether a building is “well ventilated.” Yet evidence shows that timing can be just as important as quantity. Ventilating at the wrong moment can actually make conditions worse, particularly in suspended timber floors found in so many of older UK properties.
Too much of a good thing?
For centuries, the solution to ventilating under timber floors was simple: fit air bricks for continuous air flow. These were designed to keep air moving in the void beneath the floor, the idea being that more circulation would keep the space dry and protect the structure. The flaw is that outside air is not always helpful in the following conditions:
In winter, air drawn in is typically cold and damp. Rather than drying the void, it lowers the temperature, raises relative humidity, and increases the risk of condensation and timber decay. It also allows precious heat to escape through the floorboards.
In summer, the opposite problem occurs. Warm, moisture-laden air enters a cooler void and condenses on cold surfaces, often leaving the space wetter than before.
In both cases, continuous ventilation can unintentionally fuel the very damp and rot it was meant to prevent, as well as causing draughts and loss of heat.
A smarter way to ventilate
This is where a responsive approach makes the difference. AirEx Floorvent works in a different way, using sensors and weather data to decide when ventilation is really needed. Instead of ventilating continuously, the system waits for favourable conditions, then opens to purge humidity quickly and effectively.
This adaptive approach protects the home in two ways. First, it manages underfloor humidity better, reducing the risk of mould and timber decay. Second, by closing during unfavourable periods, it cuts heat loss, reduces draughts and keeps the void warmer, supporting resident comfort and energy efficiency of the home.
Analysis of our data from thousands of homes shows that Floorvent delivers healthier underfloor conditions, and highlights where there might be problems too. We will talk more about this analysis in the next blog of the series.
Looking ahead
The insight that timing is as critical as volume is not limited to the space beneath the floor. It has much wider relevance for the way we think about ventilation in homes and AirEx is now applying these same principles to the whole home.
By combining this insight with our proven approach to responsive airflow, we can begin to shape systems that adapt in real time, delivering the right ventilation at the right moment. The ambition is to ensure homes behave more like living, breathing organisms, keeping residents healthier, reducing wasted energy, and protecting buildings over the long term.
As retrofit targets and work towards healthier homes start to align, ventilation is no longer the overlooked element. With adaptive systems, landlords can future-proof their housing stock, cut maintenance costs, and provide residents with homes that are warm, efficient, and free from damp and mould.
