# Ventilation – Things to Consider — The Healthy House Podcast > Nick Higgs of Elta Trade joins Aaron Worrall to explain why fitting an extractor fan isn't enough on its own, and how design, positioning, installation and commissioning determine whether a ventilation system actually works. *Source: https://www.thehealthyhousepodcast.co.uk/episodes/ventilation-things-to-consider* [Open in Spotify](https://open.spotify.com/episode/627w2pztXsci5GzpwTYoZL)[Watch on YouTube](https://www.youtube.com/watch?v=qMbBc6iikZw)[Listen in any app](https://pod.link/aHR0cHM6Ly9hbmNob3IuZm0vcy8xMTUxNGZmNDQvcG9kY2FzdC9yc3M/episode/Yjg1NDVjNjQtZTBjZi00Nzk1LThkOTItOWU0YzZlN2E1YmFk) ## The short version - Fitting an extractor fan is not enough on its own — the design, positioning, installation and commissioning of a ventilation system all affect how well it actually performs. - Older properties lost air and moisture naturally through gaps, chimneys and less airtight materials, so making a home more airtight with new windows, doors and insulation removes that natural ventilation and makes deliberate ventilation more important, not less. - An extractor fan needs a suitable source of replacement air to work properly, which is why trickle vents and the gaps under internal doors matter as much as the fan itself. - Continuously running extractor fans generally manage moisture better than intermittent fans that only switch on with a light or humidity sensor, because they keep clearing moisture throughout the day rather than only after it has built up. - Common ventilation installation problems include flexible ducting that restricts airflow, poor commissioning, and fans that vent into a loft space instead of outside, all of which stop a system doing its job even though a fan is fitted. - Mechanical ventilation with heat recovery (MVHR) and decentralised mechanical extract ventilation (dMEV) are two ways to ventilate a whole property, and Part F of the Building Regulations is changing what is expected in ventilation design, installation and accountability. - Dehumidifiers can help manage moisture in a room but should not be used as a replacement for effective ventilation, since they treat the symptom rather than removing the source of the problem. ## About this episode Ventilation is one of the most important, and most misunderstood, parts of creating a healthy home. As properties become more airtight, better insulated and more energy efficient, moisture and pollutants that would once have escaped through gaps and draughts can end up trapped indoors instead. In Episode 6, host Aaron Worrall is joined by Nick Higgs, National Sales Manager at Elta Trade, who has nearly 15 years of experience in residential ventilation. Nick’s central point runs through the whole conversation: fitting a fan is not the same as ventilating a property properly. The design, positioning, installation and commissioning of a ventilation system all affect whether it actually works. ## Why airtight homes need more ventilation, not less Older properties ventilated themselves almost by accident. Gaps around doors and windows, open chimneys and less airtight building materials all let air and moisture escape without anyone planning for it. Modern improvements — new windows, new doors, cavity and loft insulation — close off that accidental ventilation, which is good for heating bills but removes the pathway moisture used to take out of the building. Nick and Aaron discuss how this shift means a home that never had a damp or condensation problem can develop one after upgrades that, on paper, have nothing to do with ventilation at all. ## Intermittent versus continuous extraction One of the clearer practical points in the episode is the difference between intermittent extractor fans, which switch on with a light switch or a humidity sensor and then stop, and continuously running fans, which keep working at a low level throughout the day. Nick argues that continuous extraction generally manages moisture better, because it clears moist air as it is produced rather than waiting for it to build up before reacting. Switching a fan off to save electricity, a habit Nick flags directly, works against this. ## Replacement air and trickle vents An extractor fan does not work in isolation — it needs somewhere for replacement air to come from. Nick explains why trickle vents and the gap beneath internal doors matter as much as the fan itself: if a vent is closed, blocked, or positioned so that air bypasses the room it is meant to serve, the fan cannot pull in enough fresh air to replace what it is extracting, and the whole system underperforms even though every individual part looks fine. ## Where installations go wrong The conversation covers the installation mistakes Nick sees repeatedly: flexible ducting that restricts airflow instead of a smoother rigid run, poor commissioning that leaves a fan running below the airflow it was specified to deliver, and fans that vent into a loft space rather than outside the building, which simply moves the moisture problem rather than removing it. He is clear that ventilation systems should be installed and tested by competent professionals, not treated as a quick add-on at the end of a job. ## MVHR, dMEV and whole-house ventilation Beyond individual extractor fans, Nick sets out two whole-property approaches: decentralised mechanical extract ventilation (dMEV), which uses continuously running fans in each wet room, and mechanical ventilation with heat recovery (MVHR), a ducted system that extracts stale air and supplies fresh air while recovering some of the heat that would otherwise be lost. He talks through the benefits of each and the costs involved in installing a whole-house system, and how Part F of the Building Regulations is changing what is expected of ventilation design, installation and accountability. ## When ventilation needs change Aaron and Nick discuss how heating, humidity, occupancy and everyday habits all affect how much moisture a home has to deal with, and why ventilation problems often appear after a change in how a property is used — working from home more often, or a new baby adding extra loads of washing and drying, for example — rather than because anything about the building itself has changed. Nick also covers the importance of cleaning and maintaining extractor fans, and why a dehumidifier can help manage moisture in a room but should not be relied on as a substitute for proper ventilation. ## Nick’s Healthy House Checklist Nick closes with three practical checks for listeners: - Check your extractor fans. Make sure they are present, working, clean and producing the correct airflow for the room. - Check the supply of replacement air. Trickle vents should be open and clear, with enough space beneath internal doors for air to move through the property. - Review your everyday habits. Avoid switching extractor fans off, contain moisture where possible, and ventilate properly after showering, cooking or drying clothes. ## Who should listen This episode is for homeowners, landlords, builders and property professionals who want to understand how effective ventilation reduces condensation, prevents mould and supports a healthier indoor environment — particularly anyone who has recently upgraded windows, doors or insulation and wants to know what that means for how their home now needs to be ventilated. ## Questions this episode answers ### Why is my house getting condensation even though I have extractor fans? A fan on its own does not guarantee good ventilation — its design, positioning, installation and commissioning all affect how well it actually performs. Common problems include flexible ducting that restricts airflow, poor commissioning, and fans venting into a loft space rather than outside, any of which can leave a fan fitted but not doing its job. ### Should my extractor fan run all the time or just when I switch it on? Nick Higgs explains that continuously running fans generally manage moisture better than intermittent ones, because they keep clearing moist air throughout the day rather than only reacting after it has already built up. Switching an extractor fan off to save on running costs works against this. ### What is the difference between MVHR and dMEV? Mechanical ventilation with heat recovery (MVHR) is a whole-house ducted system that extracts stale air and supplies fresh air while recovering some of the heat from the outgoing air. Decentralised mechanical extract ventilation (dMEV) uses individual continuously running fans in wet rooms, extracting air locally rather than through one central system. ### Why do trickle vents matter if I already have an extractor fan? An extractor fan needs a suitable source of replacement air to work properly, and trickle vents are usually part of how that air gets in. If they are closed, blocked, or badly positioned so they bypass the intended airflow, the fan cannot draw in fresh air to replace what it removes. ### Why has my house started getting damp or mouldy after living there for years with no problem? Ventilation problems often surface after a change in how a home is used, such as more time spent working from home or a new baby increasing moisture from drying clothes and bathing. The ventilation needed for a property can change even when nothing about the building itself has changed. ### What does Part F of the Building Regulations cover for ventilation? Part F sets the ventilation requirements for new and altered dwellings in England, covering how ventilation systems should be designed, installed and commissioned. Nick Higgs discusses how it is changing expectations around accountability for getting ventilation right, not just fitting a fan that meets a minimum spec on paper. ## Go deeper [Condensation and Ventilation](https://www.thehealthyhousepodcast.co.uk/topics/condensation-and-ventilation) ## Share this episode [Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fwww.thehealthyhousepodcast.co.uk%2Fepisodes%2Fventilation-things-to-consider)[Share on WhatsApp](https://wa.me/?text=Ventilation%20%E2%80%93%20Things%20to%20Consider%20%E2%80%94%20The%20Healthy%20House%20Podcast%20https%3A%2F%2Fwww.thehealthyhousepodcast.co.uk%2Fepisodes%2Fventilation-things-to-consider)[Email a link](mailto:?subject=Ventilation%20%E2%80%93%20Things%20to%20Consider%20%E2%80%94%20The%20Healthy%20House%20Podcast&body=https%3A%2F%2Fwww.thehealthyhousepodcast.co.uk%2Fepisodes%2Fventilation-things-to-consider) ### Follow the show - - - - - -