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Bathroom heat recovery fan

Updated: 22 October 2026

The mirror is dripping, the silicone has a dark edge, and you are looking for a bathroom heat recovery fan that will clear the steam without dumping every bit of warmth into the yard. In a wet room the first line to read is the IP rating or the SELV note, not the recovery percentage. A room-type field that says bathroom is not a zone rating. This page is about that gap in our [single room heat recovery comparison](/hub/heating/single-room-heat-recovery). Peter F. checked the listings and public UK sources. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.

The mirror is dripping, the silicone has a dark edge, and you are looking for a bathroom heat recovery fan that will clear the steam without dumping every bit of warmth into the yard.

Our top picks

Brookvent Brookvent ONE+ 100

Best overall

Brookvent Brookvent ONE+ 100
7.0/10about £379.99
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Kair Kair K-HRV150/12RH

Rank 2

Kair Kair K-HRV150/12RH
8.4/10about £323.94
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Vent-Axia Vent-Axia HR100R

Rank 3

Vent-Axia Vent-Axia HR100R
7.6/10about £319
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On this page
  1. 1.What a bathroom fan has to move
  2. 2.Zones, IPX4 and SELV
  3. 3.What this set actually states
  4. 4.Mould the fan will not fix

What a bathroom fan has to move

Approved Document F 2021 sets two bathroom figures. An intermittent extract, the fan that runs hard after a shower, is 15 litres per second. A continuous system's high rate for a bathroom is 8 litres per second. Heat-recovery wall units in this set are usually sold as something you leave running, so the 8 litre figure is the closer language. It is still a design rate for a system, not a sticker that makes an Amazon fan compliant. LIRAST does not state an airflow at all. Vent-Axia's HR100R states 18 litres per second FID, a fan-in-duct number for a loft box, not a ceramic sleeve in the shower wall. A stated rate is still not a measurement at your ceiling.

Zones, IPX4 and SELV

The IET's BS 7671 FAQ says a 230 V fan may be placed in zones 1 and 2 if it is at least IPX4, and the isolator stays outside zones 0 to 2. EnviroVent's zoning note, written for its own trade fans, adds a 30 mA RCD and keeps the SELV transformer outside the room. Kair is the 12 V unit in this capture. Its own product page, not the Amazon spec table, states IP57 on the wall unit and IP30 on the transformer, and it tells you to keep that transformer out of zones 1 and 2. The Amazon capture says 12 V, mentions a BS 1363 connector and says hard-wiring is required. Those lines conflict.
Brookvent Brookvent ONE+ 100

Testsieger

Brookvent Brookvent ONE+ 100
7.0/10about £379.99
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What this set actually states

Brookvent's Aircycle ONE+ at about £379.99 is the only row whose bullet states IPX4, for bathrooms, kitchens and utility rooms, and it includes the controller. Two reviews at 5.0 are not a track record. The ONE 100 and ONE 150 do not show an IP number, and their controllers are extra. Kair at about £323.94 has 109 reviews at 4.2 stars and a humidistat. UK comments mention damp and shower steam. The manufacturer IP lines are not in the Amazon table. LIRAST, EUROPLAST, Weiworld, the VT100, the VT125-WIFI and the HR100R do not show an IP number. EUROPLAST's room type says bathroom, and its plug lines conflict between Type G and Schuko. A dry small bathroom in an HR100R review is a ducted loft install, not a core in zone 1.

Mould the fan will not fix

A fan changes moisture in the air. BEAMA's guide makes that distinction: ventilation deals with airborne moisture, and it does not repair a leak. If the stain tracks a pipe, grows in rain, or sits on the ceiling under the bath, find the water before you buy a core drill. Condensation on the mirror during a shower is the job a fan can influence. Mould already on the grout needs cleaning. Cold glass can still mist, which is what the three-week LINGGONGAIR window shows. Leaving a suitable fan on a low speed matches the continuous idea in Part F better than a five-minute blast. Where the cable, the isolator and the zone meet, use how to install a single room heat recovery unit. Do not put a bedroom plug-in unit in zone 2 because the socket is nearby.

Common questions

Will this stop mould in a shower room?
It can slow new growth if it actually moves enough air, it is legal in the zone, and you leave it running. It will not remove mould that is already there, and it will not stop mould fed by a leak. Clean the grout, fix any ingress, then judge the fan over the following weeks by whether the glass and silicone dry.
What IP rating do I need in zone 2?
At least IPX4 for a 230 V fan in zones 1 and 2, with the isolator outside zones 0 to 2. That is the IET FAQ, not a line we are adding to listings that omitted it. In this capture only the Brookvent ONE+ states IPX4. If your fan does not, do not invent the mark from a bathroom room-type field.
Is a SELV fan safer?
It can be, because the transformer stays outside the wet zones and the fan itself is 12 V. Kair is the SELV-style unit here, and the manufacturer page is where the IP57 and IP30 figures sit. You still need a competent person for the transformer and the conflicting plug language on Amazon. SELV is not a reason to skip isolation or Part F airflow.
What airflow should a continuous bathroom fan have?
Part F's continuous high rate for a bathroom is 8 litres per second. The intermittent figure is 15 litres per second. EUROPLAST's 29 cubic metres per hour converts to about 8. Kair's 19 converts to about 5.3. The HR100R's 18 litres per second is a duct figure. None of those sentences is a test in your shower.
Which listing actually says IPX4?
Brookvent's Aircycle ONE+ at about £379.99. The other eleven do not print IPX4 in this capture. Kair's IP57 and IP30 are on the manufacturer page, not in the Amazon spec table. Read that page, then the zone, before you treat Kair as the splash-rated alternative.
Can I plug a bedroom unit into a bathroom?
No. The VT100's UK plug and bedroom room type do not make it an IPX4 zone 2 fan. A new connection in a bathroom is electrician work, with the isolator outside the zones. A plug on a bedroom listing is not a waiver.
Does the fan dry a damp wall?
It dries air, not a saturated wall, a failed seal or a pipe leak. If the plaster is wet to the touch away from the shower, find the source. A heat-recovery percentage does not change that. BEAMA's point is the same: airborne moisture is the ventilation job.

Related pages

Single room heat recovery buying guide

Heat recovery fan vs extractor fan

Single room heat recovery

Best single room heat recovery UK: who should skip

How to install single room heat recovery: the hole

Sources

Public UK sources named below. amazon.co.uk prices, stars and review counts on these twelve listings were taken from the listings saved on 20 October 2026. Page updated October 2026.

  1. Approved Document F Volume 1, 2021 (retrieved 20 October 2026)
  2. GOV.UK Approved Document F (retrieved 20 October 2026)
  3. Elta Trade, Part F 2021 (retrieved 20 October 2026)
  4. IET BS 7671 Section 701 FAQ (retrieved 20 October 2026)
  5. BEAMA specifier ventilation guide (retrieved 20 October 2026)
  6. Kair heat recovery room ventilator (retrieved 20 October 2026)
  7. Permagard Kair install guide (retrieved 20 October 2026)
  8. MDPI Energies, ceramic-core measurements (retrieved 20 October 2026)