Centrifugal fan buying guide
Updated: 21 October 2026
You are looking at a tired bathroom grille and, in the same amazon.co.uk search, a plug-in blower at about £12.99. A centrifugal fan buying guide has to split those two jobs before duct length, litres per second, or a timer. Hard-wired extractors and 12 V blowers in this set are not one ranking. This page is the order of decisions. The [centrifugal fan comparison](/hub/cooling/centrifugal-fan) is the table once you know which group you are in. Peter F. compared those amazon.co.uk listings and public UK guidance on 20 October 2026. There was no lab test of airflow. A qualifying purchase can earn a commission at no extra cost to you.
You are looking at a tired bathroom grille and, in the same amazon.co.uk search, a plug-in blower at about £12.99.
You are looking at a tired bathroom grille and, in the same amazon.co.uk search, a plug-in blower at about £12.99. A centrifugal fan buying guide has to split those two jobs before duct length, litres per second, or a timer. Hard-wired extractors and 12 V blowers in this set are not one ranking. This page is the order of decisions. The centrifugal fan comparison is the table once you know which group you are in. Peter F. compared those amazon.co.uk listings and public UK guidance on 20 October 2026. There was no lab test of airflow. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Job | Stated airflow | Control | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Vortice Vortice Ariett T | Bathroom extract | 19.4 L/s | Timer 3–20 min | 9.0 | about £52.50 | View offer |
| Best value |  NAVESO NAVESO 97 mm | Plug-in blower | 55–58 CFM | Variable 3–12 V | 8.4 | about £12.99 | View offer |
 Manrose Manrose CF200S | Bathroom extract | Not on listing | Timer not stated | 7.3 | about £37.99 | View offer |
On this page
Extractor or blower
A wet room that must send air outside needs a mains extractor on a duct. A directed jet for charcoal, a cabinet, or a bench needs a 12 V blower with a UK plug on the controller. If the second description is yours, stop reading extract rates and use the centrifugal blower fan for a BBQ. If the first is yours, ignore every blower in this set. None of them states an IP rating, and a cubic-feet-per-minute claim is not a bathroom extract rate. The Vortice, Manrose and Nuaire are the extractors. A kit at about £12.99 is a side-outlet blower, not a cheap version of those three.
Duct length before the model
Once you are buying an extractor, the duct decides the mechanism. An axial fan is the short through-wall tool. Which? describes axial runs of about 2–3 metres. Domus uses about 1.5 metres, and Vent-Axia treats a 90-degree bend as roughly another metre of duct. Those figures do not agree, and they are not a legal limit. Domus describes a surface centrifugal fan, scroll and motor at the grille, as generally suitable up to about 6 metres. That is Domus’s description, not a regulation. This set has no inline model. If the bathroom is internal, you leave this table. The centrifugal vs axial extractor fan page is that mechanism choice. A 2026 revision of Approved Document F prefers rigid duct and a 2.0 metre practical maximum unless you show design evidence. It is not in force until 24 March 2027.
Litres per second, not free air
England’s intermittent table asks for 15 litres per second in a bathroom, 30 in a utility room, and 6 in a room used only as a WC. A kitchen is 30 litres per second if the hood extracts outside, and 60 if it does not. The terminal should be as high as practicable and at most 400 mm below the ceiling. A sticker figure is not that installed test. A long flexible duct, a sag, or a crushed bend can pull the number down. The Vortice states 19.4 litres per second, also 70 cubic metres per hour. Manrose’s own CF200 page is about 31 litres per second; the amazon listing does not print it. The Nuaire manual states up to 60 litres per second on a short through-wall duct. None of those lines is a Part F pass.
Timer, zone and the listing
Where the room has no openable window, Approved Document F asks for at least 15 minutes of overrun after you leave. The Vortice timer runs from 3 to 20 minutes, but only with permanent live, switched live and neutral. B&Q’s note for model 11976 says the timer cannot be used without those three connections. Wired without the overrun, it stops with the switch. The Manrose CF200S does not state a timer. That function is the CF200T. The Nuaire lists a timer, a humidistat and a pullcord on 24 V SELV. Buy it when you need humidity sensing or the SELV conversion, not only a 15-minute overrun. Permanent live and a SELV conversion are electrician work. The how to install a centrifugal bathroom fan page is the stop point, not a connection diagram. A 230 V fan in zone 1 or zone 2 needs at least IPX4, on a 30 mA RCD, with the isolator outside the zones. The Vortice states IPX4. The blowers state none.
Common questions
Do I need a centrifugal extractor or a plug-in blower?
You need a centrifugal extractor if the job is to pull air from a bathroom, kitchen, WC or utility room to outside through a duct. You need a plug-in blower if you want a directed 12 V jet for charcoal, a cabinet, or a bench. The blower has no IP rating in this set and no 15 litres per second claim. A kit at about £12.99 is not a cheap version of the Vortice.
How long a duct can a centrifugal bathroom fan serve?
Domus describes a surface centrifugal fan as generally suitable up to about 6 metres, and axial fans as about 1.5 metres, while Which? allows axial fans about 2–3 metres. Those are guides, not a regulation. Every bend and every sag still cuts the installed litres. If the motor should sit in the loft, you want an inline fan, which this set does not stock.
Is 15 litres per second the number on the box?
In England, 15 litres per second is the intermittent bathroom rate in Approved Document F. It is the airflow the installation has to deliver, not the free-air sticker. The Vortice states 19.4 litres per second. That can fall once the duct is long or flexible. A building-control measurement is a competent person’s job, not a sum on the listing.
When does the fan need a timer?
Where the room has no openable window, England’s guidance asks for at least 15 minutes of overrun after you leave. The Vortice can be set from 3 to 20 minutes if permanent live, switched live and neutral are present. The Manrose CF200S does not state a timer. A room with an openable window can be switched with the light, though a timer is still the usual way to clear steam after you leave.
Do Scotland and Northern Ireland use the England table?
No. The 15, 30 and 60 litre figures cited here are England’s Approved Document F. Scotland and Northern Ireland have their own regulations. The practical checks on this page still apply: know the duct, do not trust free air, and do not fit a non-timer fan in a windowless room if your nation requires overrun.
Related pages
Sources
Public UK sources named below. amazon.co.uk prices, stars and review counts on these listings were read on 19 October 2026. Page updated 20 October 2026.
- Approved Document F volume 1, 2021 and 2026 PDFs — rates, height, overrun, future duct rules (retrieved 2026-10-20)
- BEAMA Part F bitesize guide — 15 l/s, short flexible duct, 0.5 W/(l/s) (retrieved 2026-10-20)
- Domus Ventilation — axial about 1.5 m, centrifugal about 6 m, Part L note (retrieved 2026-10-20)
- Which? bathroom extractor buying guide — axial versus centrifugal (retrieved 2026-10-20)
- IET Wiring Matters BS 7671 FAQ — IPX4 in zones 1. (retrieved 2026-10-20)
- SELECT bath and shower pocket guide — zone sizes (retrieved 2026-10-20)
- Manrose CF200S page — 110 m³/h, about 31 l/s, IPX4, standard model (retrieved 2026-10-20)
- Nuaire Cyfan manual — 24 V motor, SELV, up to 60 l/s (retrieved 2026-10-20)