Continuous extract fans (dMEV) in Essex

A dMEV (decentralised mechanical extract ventilation) fan is a low-energy extract fan that runs continuously at a quiet trickle speed and boosts automatically when it senses humidity or a light switch. Because it never fully switches off, moisture is removed steadily instead of building up between showers.

We carry out continuous extract fans (dMEV) across Essex, including Harlow, Grays, Braintree, Brentwood and Southend-on-Sea. Prices use East of England rates. The survey is free for new installations on the UK mainland, and the quote that follows is fixed and in writing.

dMEV fans in Essex at a glance

Area: Essex
Towns listed: 32, largest Southend-on-Sea
Postcode districts: E4, IG8, CM16, CM18, SS0 and SS1
Price region: East of England
Survey: Free survey (UK mainland)

What continuous extract fans (dMEV) involves

On trickle speed they are barely audible and use very little power; on boost they reach the higher continuous-extract rates in Approved Document F (in England, at least 13 litres a second for a kitchen, 8 for a utility room or bathroom and 6 for a WC). Landlords and housing associations often choose them because tenants cannot switch them off and forget them. Under Approved Document F, continuous mechanical extract systems need commissioning: the airflow on both trickle and boost is measured and recorded.

Bathroom and en-suite

Through-wall or ceiling fans with humidity-controlled boost.

Kitchen

Higher-rated continuous fans where a ducted hood is not practical.

Whole-home dMEV upgrade

Every wet room converted at once, with trickle vents checked in the habitable rooms.

Guide prices in Essex

Continuous extract fans (dMEV) guide prices in Essex
Work	Guide price
Continuous-running extract fan (dMEV) with humidity boost, flow tested (per fan)	£360–£625 inc VAT
Airflow testing and commissioning sheet for extract fans (up to 6 fans) (per home)	£150–£310 inc VAT

Guide prices using East of England rates. Prices include VAT at 20%. A guide price is not a quote: we confirm a fixed price in writing first.

When to get it looked at

Occupants switch fans off because of noise
Mould keeps returning in a bathroom with a working fan
You manage rental homes and want ventilation that cannot be switched off

Rules in England

In England, ventilation is covered by Part F of the Building Regulations and its guidance, Approved Document F (2021 edition). For homes, it sets minimum extract rates such as 15 litres a second for a bathroom and 30 or 60 for a kitchen, and expects mechanical systems to be airflow-tested.

How the job runs

Survey
Specify
Fit
Commission
Record

Towns we cover in Essex

Questions about continuous extract fans (dMEV) in Essex

Is the survey free in Essex?

For new installations on the UK mainland, yes. The survey is free and the quote that follows is fixed and in writing. Servicing, testing and repair visits are charged, and we confirm the cost before booking.

Is it expensive to run a fan all the time?

No. dMEV fans use very little electricity on trickle speed, typically a few watts, so running costs are low compared with the condensation and mould they prevent.

Are continuous fans noisy?

A correctly sized dMEV fan is very quiet on trickle; most people only notice it on boost. Noise usually means the wrong fan or a poor duct.

Which rules apply to ventilation in Essex?

In England, ventilation in new and altered homes is covered by Approved Document F of the Building Regulations. Landlords also have duties under the Housing Health and Safety Rating System, and workplaces must be ventilated under the Workplace (Health, Safety and Welfare) Regulations 1992.

Which towns in Essex do you cover?

All of Essex, including Harlow, Grays, Braintree, Brentwood and Southend-on-Sea. If your town is not listed, send the postcode and we will confirm.