Loos are one room in the home that actually want to supply a constantly comfy surroundings – in spite of everything, you’re prone to spend a lot of your time on this area in a state of partial or whole undress. Not the place for sub-zero temperatures.
You would possibly assume you’re doing all the precise issues – putting in one of many greatest rest room extractor followers, becoming accurately sized heated towel rails and radiators and even an underfloor heating system – but in case you are nonetheless discovering your self shivering while you step out of the bathe, one thing is just not proper.
It’d shock you to study that your extractor fan might be the wrongdoer right here – we spoke to the consultants to clarify why this may be and the best way to put a cease to this icy challenge as soon as and for all.
Can rest room extractor followers make a room really feel colder?
Many individuals have by no means thought-about that their extractor fan may be interfering with their rest room heating, inflicting their room to really feel chilly but, in accordance with the consultants, it is a way more widespread downside than you would possibly assume.
“Extractor followers play an vital function in controlling moisture, but when they are not accurately specified or arrange then they will make a a lot greater influence on warmth loss than householders could realise,” explains Ryan Marshall, director of Marshall Clear Warmth and Energy. “Loos are normally small, extremely heated areas, so even a modest extraction price can exchange heat air with chilly air in a short time – particularly in colder months.”
Martyn Fowler, founding father of Elite Renewables, elaborates. “The fan adjustments how air behaves in a managed area. When an extractor fan runs, it creates unfavourable stress within the rest room. Which means air has to return from someplace to exchange what’s being pulled out.
“If the door is open, it’d pull heat air from the remainder of the home,” continues Martyn. “If the door is closed and the room is sealed, it might attract colder air by way of gaps within the constructing envelope, comparable to trickle vents and even the fan duct itself if there’s no backdraught damper.”
There are literally a number of the reason why rest room extractor followers would possibly find yourself inflicting extra issues than they clear up – we’re right here to disclose them.

Ryan Marshall is managing director of Marshall Clear Warmth and Energy, a UK-based specialist in renewable heating and vitality options. A time-served heating engineer with an MBA and Chartered Supervisor standing, Ryan based the enterprise in 2008 and has since led its progress with a robust deal with clear warmth applied sciences, vitality effectivity and sensible decarbonisation. He’s keen about serving to houses and companies transition to low-carbon vitality with confidence.

Founding father of Elite Renewables, Martyn Fowler is likely one of the UK’s main renewable expertise consultants, working with warmth pumps for the final twenty years. His ardour for decarbonisation matched with a deep technical expertise of the expertise make him one of many trade’s go-to consultants for all issues renewable.
1. Followers which can be left to run for too lengthy
Loos can grow to be steamy locations which means the temptation will be to go away your extractor fan operating at full blast lengthy after it has been used so as to eliminate all that damp, scorching, muggy air – however this might be an enormous mistake.
“One of the crucial widespread points we see is followers operating for longer than essential,” reveals Ryan Marshall. “Lengthy overrun instances or continuous-run fashions can take away extra heat air than your heating system can comfortably exchange, which leaves the room feeling noticeably colder.”
“The commonest challenge is followers that run consistently or keep on far longer than they should,” agrees Michael Zohouri, founding father of Pyramid Eco. “If the fan retains pulling air out after the moisture has cleared, you’re simply eradicating heat air and changing it with chilly from different components of the home.”
The answer: “Begin by checking how the fan is managed,” says Michael. “If it’s wired to the sunshine change, take into consideration upgrading to a humidity-sensing mannequin. These solely run when moisture ranges are excessive and change off when issues are dry once more. So that you don’t lose any warmth simply because somebody forgot to show it off.”

Michael Zohouri is the corporate founder, bringing over a decade of expertise to the function. His experience spans energy-efficient retrofitting tasks, together with insulation, photo voltaic and warmth pump installations. Dedicated to addressing challenges like thermal bridging and enhancing air high quality, Michael focuses on creating more healthy, extra sustainable residing environments whereas decreasing vitality prices for residents.
2. Defective or lacking backdraught damper
All extractor followers used for rest room air flow ought to be fitted with a backdraught shutter, a valve that opens when the fan is operating to let stale air out however that ought to then routinely shut when the fan is just not in use.
“It’s actually vital that the fan has a correct backdraught shutter that seals totally when the fan is off,” explains Martyn Fowler. “With out that, the duct can act as a pathway for chilly air to maneuver again into the toilet.”
“If the fan hasn’t received a working backdraught damper, or if the ducting round it isn’t sealed correctly, chilly air can come again in from outdoors,” provides Michael Zohouri. “Typically you’ll truly really feel the chilliness coming straight by way of the fan.”
The answer: Have a look and test that the backdraught flap is working and sealing correctly when the fan is off.
“Insulated ductwork and a good-quality non‑return valve will make an enormous distinction by stopping chilly air being pulled or blown again into the toilet when the fan isn’t working,” says Ryan Marshall.
3. Selecting a fan that is too highly effective
Selecting an extractor fan that’s not specified accurately for the scale of you rest room could cause all types of issues, warmth loss included – if it’s not highly effective sufficient it will not pull the stale air and steam out correctly, however whether it is too highly effective you would end up losing each warmth and vitality.
“One of the crucial widespread points is extreme air extraction – if a fan is just too highly effective for the room dimension, it might pull heat air out sooner than it’s changed, making a noticeable chill,” explains Ruth MacEachern, product supervisor at air flow specialists EnviroVent.
“Larger isn’t all the time higher,” agrees Michael Zohouri. “If the fan is rated for a a lot bigger room it would pull out an excessive amount of air too shortly and take the warmth together with the steam.”
The answer: Select an extractor fan with the proper extraction price in your rest room’s dimension. Calculate its quantity by multiplying it size by its width by its top (L x W x H). It’s advisable to have a minimum of 4 air adjustments per hour so you’ll then multiply the determine you bought by 4. This might provide the required extraction price of your fan in m3/h.

Ruth MacEachern is product supervisor at EnviroVent, one of many UK’s main producers and installers of sustainable, low-energy home air flow methods.
Manrose QF100T Quiet Extractor Fan
This well-priced extractor fan ticks so many packing containers – quiet to run (27dB) and straightforward to put in, it additionally has a backdraught shutter and overrun timer. It’s appropriate for the standard 100mm duct.
Vent-Axia VASF100T Rest room Extractor fan
This extractor fan is tremendous quiet to run (14dba) options two velocity settings and has an adjustable overrun timer – plus, backdraught shutters are included. It additionally seems to be fairly sensible.
Devola Rest room Extractor Fan with Humidistat
Whereas not as quiet because the others right here (30dBA), this extractor fan incorporates a humidistat to set between 60-90% and an overrun timer which means it will not be operating for longer than wanted.
4. Unhealthy extractor fan positioning
It’s no good simply sticking your extractor fan in any outdated place inside your rest room structure – whilst you may not need it ruining your rest room design concepts, you really want to provide some thought to its location if you don’t need it to be the reason for post-bath shivering.
“Structure issues,” states Martyn Fowler. “If the extractor is positioned instantly above the bathe or bathtub and runs for lengthy intervals, it might strip heat air in a short time and trigger a noticeable drop in temperature.”
The answer: “In compact loos, drawing air from the next nook or barely away from the bathe can nonetheless take away moisture successfully, however in a extra managed manner,” advises Martyn.
5. Pace settings are being ignored
Working your extractor fan flat out in a quest to beat mould within the rest room is just not the most effective methodology of getting essentially the most out of it – simply one other manner by which it might make your rest room really feel chilly.
“Fan velocity performs a key function,” says Martyn Fowler. “Many more moderen fashions provide variable velocity settings, which makes an enormous distinction in smaller loos. As an alternative of operating flat out on a regular basis, the fan can function at a decrease price for background air flow and solely ramp up when steam ranges rise. That reduces how a lot heat air is eliminated and helps maintain the room temperature extra steady.”
The answer: Select an extractor fan with variable speeds and that responds to the moisture ranges in your area.
“A humidity-controlled fan works on demand,” explains Martyn Fowler. “It switches on when moisture ranges rise, and switches off as soon as the air has dried out. Which means you’re eradicating steam when it’s wanted, however you’re not repeatedly pulling heat air out of the room as soon as the job is completed.”
6. Uninsulated fan ducting
It’s essential, if you wish to preserve a snug temperature in your rest room, that you just test the best way your extractor fan is ducted to outdoors. It is usually actually vital to make sure that the ducting you employ is insulated.
“Poorly sealed ducting or gaps across the fan housing can permit chilly air to enter from outdoors,” explains Ruth MacEachern.
The answer: “Be sure your ducting runs correctly to an out of doors wall or roof vent, and that it’s insulated if it goes by way of a chilly loft,” advises Michael Zohouri. “That stops condensation forming within the duct and helps forestall chilly air from being pulled in.”
7. Drawing recent air from a chilly spot
Together with checking that ducting seals are intact and that insulation has been thought-about, do take into consideration how the supply of your recent air might be affecting rest room temperatures.
“When a fan pulls humid air out, it needs to be changed from some other place within the property,” picks up Ryan Marshall. “If that ‘make-up’ air is being drawn from unheated areas, comparable to hallways, loft voids or by way of draught factors, the temperature drop will be vital, particularly in older or much less hermetic houses.”
The answer: Together with ensuring your recent air is just not coming from an unheated space, and addressing draught proofing all through your house, Michael Zohouri has one other resolution.
“Maintain the door closed when the fan is operating,” he says. “This enables the fan to attract air from below the door quite than from the remainder of the home.”
FAQs
In case you are renovating a toilet that at present has no extractor fan, you could be eager to keep away from any further disruption – however is an extractor fan a authorized requirement?
The UK Constructing Rules state that loos should have some type of air flow, though this may be supplied within the type of both an extractor fan or an openable window. Nevertheless, within the case of recent builds, loos are required to be fitted with mechanical air flow (because of them being extra hermetic).
Even in case you are not constructing a brand new home, it’s nonetheless extremely advisable to suit an extractor fan. Opening a window for extended intervals within the depths of winter to cope with humid, stale air is impractical, plus mechanical air flow is an effective way to keep away from points with damp or mould arising.
When you’ve got discovered damp within the rest room you shouldn’t solely tackle your air flow strategies, but in addition be looking out for leaks in pipework or behind tiles. If you happen to can, opening home windows for a couple of minutes each day will assist too.


