Greater London · Air handling unit cleaning
Air handling unit cleaning in Farnborough, Greater London
AHU cleaning in Farnborough, surveyed first and signed off with a written report and pictures. Call for a fixed quote.
- Dust built up on fan impellers
- Air handling units with blocked filters
- Dirty coils holding back the airflow
AHU cleaning in Farnborough, done properly
Every supply and extract system relies on the air handling unit at its centre: it draws air in, filters it, heats or cools it and pushes it round the ductwork. Whatever builds up inside it travels with that air, which is why we clean the unit itself, not just the ducts. The work covers drain trays, filter sections and supply and extract fans, and the jobs we see most are filters that are clogged or overdue and dirty fans and fan housings.
Across London, offices, hotels, schools and healthcare buildings rely on mechanical ventilation, much of it supplied through air handling units on roofs or in basements. In a building in Farnborough, dust and debris build up in the units and ductwork over time.
Nothing is signed off by word of mouth: a written report, dated and illustrated with photos, and for TR19® Grease cleans, a certificate issued through the BESCA VHE portal. It shows what was done and what, if anything, couldn’t be reached.
- Place
- Farnborough (BR6)
- Wider area
- Greater London
- Records
- Written report with photos
- Price
- A fixed quote up front
- When we work
- Out of hours as standard, 24/7 emergency line
- Telephone
- 0345 646 2711
- Page updated
- 30 October 2026
Keeping the system healthy
Think of this as the after-treatment advice, in brief:
- Make sure the unit’s access doors open easily
- Flag stale or damp smells in the supply air
- File each AHU report in the maintenance log
- Plan the next inspection before the last report gets filed away
Keep filter changes on schedule between cleans, as that does more than anything to keep the unit clean. Log every change so it’s easy to see when the next is due.
Keep the unit’s doors and panels in working order. If a section is hard to get into, it tends not to get checked.
Nearby places to Farnborough
Other services in Farnborough
Why deal with it now?
Standing water in a drain tray doesn’t clear itself. Left alone, it can overflow, leak into the plant area or ceiling below and spread smells through the system. Clearing it now is a much smaller job. Leaving it on a busy London site only adds to the work.
One small site or a whole estate, the quote is built the same way: the work involved, the access and the timing. You will have a fixed price before any work starts.
Why choose Duct Doctor in Farnborough
- In business since 2009
- CHAS and SafeContractor accredited, with ISO 9001
- Fixed quotes from a survey or photos
- Work around your opening hours, with 24/7 emergency cover
Take a look at our cost guide and our accreditations and certificates.
Managing agents and facilities teams in Farnborough
When the building owner and the occupier are different, it’s worth checking the lease for who maintains the systems. We’re happy to deal with either side and send the paperwork to whoever needs it.
Facilities teams in offices, schools and healthcare sites book us too in Farnborough and across Greater London. Larger estates can be phased building by building around the people who use them.
Ventilation in Farnborough buildings
The FSA’s food hygiene register lists about 7 schools, colleges and universities and about 13 care, childcare and hospital premises with registered kitchens or food service in Farnborough and the streets around it, up to about 1.5 miles out. Classrooms, bedrooms and care spaces are often served by ducted air, and that ductwork collects dust over time. London plant rooms are often on roofs or in basements reached through occupied floors. Orpington Hospital is the nearest hospital, about 0.9 miles east of Farnborough. If you run a surgery, clinic or care home, your ventilation deserves the same care as a hospital’s, on a smaller scale.
For schools like Farnborough Primary School, the holidays are the usual time to inspect and clean ventilation.
Farnborough is about 2 miles south-west of Orpington, in Greater London. Whether your site is in the middle of Farnborough or further out, we cover AHU cleaning for every kind of premises, from small sites to large estates. Farnborough is one of 764 places in Greater London we cover for commercial clients. London is in our area too, about 12 miles from Farnborough.
Every address in BR6 is covered for AHU cleaning, from busy streets to back roads. That includes premises on Tye Lane, Peel Road and Pitt Road and the roads around them. Close by, we work in Green Street Green (1 mile south-east), Locksbottom (1 mile north-west), Crofton (1 mile north), Farthing Street (1 mile south-west) and Downe (2 miles south-west). We also work in nearby towns such as London (12 miles north-west), City of Westminster (15 miles north-west), Marylebone (15 miles north-west), Kensington (15 miles north-west), St Pancras (14 miles north-west) and Shoreditch (13 miles north-west).
Around Farnborough
Typical jobs here are in premises near Newstead Wood School, South Park and The Buff pub, among other places. The nearest railway station is Orpington station, roughly 1.2 miles north-east of the centre. A little further out are Orpington Hospital (0.9 miles east) and Crofton Roman Villa (1.1 miles north-east). For a walk, there’s Downe Bank Nature Reserve and Summer Hill.
How it works
We are used to working while the site is closed. A lot of visits happen overnight or at weekends, so the site can open as normal afterwards. The visit itself takes half a day to a full day per unit, with large plant planned over several shifts. Before any visit in Farnborough, we agree where the van can stop and how equipment reaches the system.
- We start with a survey of the unit and a fixed quote for the work.
- We arrange the shutdown with your staff and sheet the area.
- We clean or change the filters as agreed, then clean the coils, fan and internal panels.
- Drain trays are cleared and cleaned and the outlet checked.
- A TR19® certificate and photo report follow the clean.
How to prepare
- Mention any sign-in, permit or induction we need
- Dig out any earlier paperwork for the system
- Make sure someone can let us in and lock up afterwards
Get a fixed quote
Getting a quote doesn’t take long. Send a few details and pictures, and we usually reply with a fixed quote within one working day. Where a survey is needed, we arrange a time that suits the site.
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Common problems we fix in Farnborough
An AHU’s intake draws in outdoor air and everything in it: dust, pollen, leaves and debris. The intake section and first filters take the brunt, and some travels further into the unit.
Any of these means the system needs a check-up:
- Debris and leaves in the fresh air intake
- Plant that has been serviced but not cleaned
- Fan sections that haven’t been cleaned in years
- Filters that are clogged or overdue
Healthcare buildings such as Orpington Hospital, about 0.9 miles east, depend on their ventilation; if you manage a surgery, clinic or care home near Farnborough, yours matters too.
Questions to ask before booking
- Whether the work can be done while the site is closed
- How areas they can’t reach will be recorded
- What records you will receive afterwards
- If the quote is a fixed price or an estimate
How the job changes from site to site
Heating and cooling coils
Because cooling coils run wet, the dirt on them tends to cling. We clean the coil and the tray beneath it together.
Fans and fan sections
The fan section is cleaned with the unit switched off and isolated in agreement with the site.
Honest limits
To be straight with you, some problems need a different fix:
- Problems with the unit’s controls or sensors
- The supply and extract ducts, quoted separately
- Breakdowns that need a mechanical engineer
If in doubt, give us a ring on 0345 646 2711 or email us and we’ll say what we think.
Where we work
- Internal panels
- Filter sections
- Supply and extract fans
- Drain trays
- Dampers and louvres
- Heating and cooling coils
Your questions about AHU cleaning in Farnborough
Can a school’s ventilation in Farnborough be done out of term time?
Yes, holiday work suits schools best. Around Farnborough, the Food Standards Agency lists about 7 schools and colleges with registered kitchens within a mile and a half or so. Tell us your holiday dates and we’ll book the visit for when the site is empty.
How do you handle parking and loading in Farnborough?
Tell us where a van can stop near your site in Farnborough, and about any building rules on loading. Night visits tend to make loading easier on London streets.
Which accreditations do you hold?
Our accreditations are CHAS, SafeContractor and ISO 9001, and we’re a BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease. The Vent Hygiene Elite scheme is run by BESCA and audited independently.
What do you do to protect the area?
By covering it before any work starts. We keep the work contained and clean down when we finish.
What does AHU cleaning cost?
It depends on the site, so we quote each one individually. To get one, call 0345 646 2711 or send us an email and tell us about the site and its opening hours.
Do you have a 24/7 line?
Yes, 24/7. Our office is open from 8am to 6pm on weekdays, with the emergency line covering every other hour.
How long does it take to clean an air handling unit?
The work takes a single shift for a typical unit, longer for large or heavily soiled ones. Large plant can be split over several shifts, and you can call us on 0345 646 2711 or drop us a line to plan it.
Do you give a certificate after the clean?
Yes, a TR19® certificate and a photo report. It includes a recommended date for the next check.