Hertfordshire · Air handling unit cleaning
Air handling unit cleaning in Felden, Hertfordshire
Our technicians work in Felden on cleaning of air handling units, including filters, coils, drain trays, fans and internal surfaces. Out-of-hours visits, a fixed quote and a written report with photos on every job.
- Leaves and litter drawn into the unit
- Dirty filters cutting the airflow
- Coils clogged with dust and debris
Felden buildings and their air
Going by the FSA’s register, there are about 17 schools, colleges and universities and about 19 care, childcare and hospital premises serving food within roughly a mile and a half of the centre of Felden. Where buildings like these have air handling units, filters, coils and drain trays need regular attention. The nearest hospital to Felden is Hemel Hempstead Hospital, about 1.5 miles north. Clean air matters most where people are unwell, and that is as true in a care home as in a hospital. Felden is about 22 miles from central London, well within the area we cover across London and the South East. We work evenings, overnight and at weekends, so the visit fits around the site.
For schools like Nash Mills Church of England Primary School, the holidays are the usual time to inspect and clean ventilation. If you run an office near Apsley station, its supply ductwork can gather dust for years before anyone looks inside.
Felden is about 2 miles south of Hemel Hempstead, in Hertfordshire. Wherever you are in the HP3 postcode area, we can take on AHU cleaning. Across Hertfordshire, we cover 381 places, and Felden is one of them. You can also see our page for London, about 22 miles away.
Postcode districts we cover here for AHU cleaning: HP3 and WD4. We cover sites on Pond Road, Rose Lane and Lower Road and nearby roads. We also cover Nash Mills (1 mile east), Rucklers Lane (1 mile south), Apsley (1 mile north-west), Bennetts End (1 mile north-east) and Kings Langley (1 mile south-east). Within a short drive, we also cover Watford (5 miles south-east), St Albans (6 miles east), Welwyn Garden City (12 miles east), Harpenden (8 miles north-east), Hatfield (10 miles east) and Borehamwood (9 miles south-east).
Landmarks near Felden
Typical jobs here are in premises near Kings Langley School and The Paper Mill pub and the streets around them. There’s a railway station in Felden itself: Apsley station. Nearby you will also find Hemel Hempstead Hospital (1.5 miles north). Green spaces nearby include Long Deans and Verulamium Lake.
AHU cleaning for kitchens and businesses in Felden
A cooling coil drips condensate into a tray that should drain away. When the drain blocks, water sits there and the tray turns slimy, in the airstream that feeds the building. Clearing and cleaning the tray is central to every AHU clean. If you have intake sections clogged with outdoor debris and air handling units never cleaned inside, we can put it right.
Smaller buildings around Felden often keep their ventilation units in a roof void or plant cupboard, where they’re easy to forget. Every unit, large or small, has filters, coils and a drain tray to keep clean.
We are CHAS and SafeContractor accredited, we hold ISO 9001 and we’re fully insured. On top of that, we are a BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease, trading since 2009.
- Where
- Felden (HP3, WD4)
- Wider area
- Hertfordshire
- Records
- Written report with pictures
- Price
- Fixed quote, typically within a working day
- Hours
- Out of hours as standard, 24/7 emergency line
- Phone
- 0345 646 2711
- Reviewed
- 30 October 2026
What the work involves, part by part
Internal casing and panels
Dust settles on every internal surface of the unit. Each section is cleaned from the intake through to the outlet.
Fans and fan sections
Every bit of air passes the fan, so a dirty fan sends dirt downstream. The impeller, its housing and the fan chamber are cleaned.
The process
We are used to working while the site is closed. Evenings, nights and weekends are when much of our work happens, so a kitchen or building can carry on as usual the next day. On site, the work takes a single shift for a typical unit, longer for large or heavily soiled ones. Tell us about any gates, ladders or locked plant areas at your site near Felden when you book.
- We look at the unit and the plant area during the survey.
- We sheet the area and the unit is isolated.
- Dirt and debris are removed from each section.
- Coils and trays are cleaned and the condensate drain cleared.
- We close every panel, hand the unit back and send the report and certificate.
Preparing for the visit
- Tell us where we can park and unload
- Let us know how we reach the system, including roofs, risers and plant rooms
- Mention any sign-in, permit or induction we need
Ask for a quote
The quickest way to a quote is to send photos: the system from a couple of angles, plus any access panels or hatches. Tell us what kind of site it is and when it’s open, and we can price many jobs without a visit.
Advice
In-house cleaning or a specialist?
Away from the kitchen, the in-house job is mainly checking: clear grilles, a log of filter changes and reporting anything odd. The inside of ducts and units needs a specialist.
When your team notices a problem between visits, like drips, unusual noise, smells or damaged filters, they should report it rather than try to fix it. We will take a look and give you a fixed quote.
When to call us in Felden
No filter stops everything. The fine dust that passes the filters lands on the coils, the fan and the internal panels, a little more each month.
Clients usually contact us when they notice one of these:
- Dirty fans and fan housings
- Odours coming through the supply air
- Leaves and litter drawn into the unit
- Plant that has been serviced but not cleaned
Healthcare ventilation, from large hospitals like Hemel Hempstead Hospital (about 1.5 miles north) to small clinics, depends on clean filters, coils and ducts.
Questions to ask before you book
- Whether they’re fully insured
- Whether the quote is based on a survey or photos
- How they set the interval to the next visit
- How areas they can’t reach will be recorded
Aftercare tips
Here’s the after-treatment advice, in brief:
- Store the TR19 paperwork where auditors can find it
- Flag stale or damp smells in the supply air
- Report water on the plant room floor
- Don’t store bins or materials near the intake
If the ductwork hasn’t been cleaned, consider it next. Cleaning the unit and ducts together gives the best result, and we can survey both.
Change or clean filters on time. Overloaded filters let more dirt through to the coils and fan.
What affects the cost of AHU cleaning
The price is fixed before any work begins. It takes into account:
- Whether we need access equipment or extra panels
- Whether it’s a one-off visit or part of a schedule
- When the work can happen, such as evenings, overnight or weekends
- Site requirements such as sign-in and permits
What you pay depends on how big the system is, what state it’s in and access to every part of it. We give you a fixed price before we start, so there are no surprises.
Helping us quote
Photos and a few facts are often enough to price the work. Useful things to send:
- How we’d reach plant on a roof or in a plant room
- Detail shots of panels, filters and grilles
- Where the site is and what kind of site it is
- Anything you’ve noticed, such as smells, noise, drips or poor airflow
To help us quote: the address, the type of site and when it’s open, photos of the system and the last certificate or report, if there is one. Then phone us on 0345 646 2711 or use the quote form.
Felden: your questions answered
Do you clean school ventilation in Felden in the holidays?
Yes, holiday work suits schools best. Food Standards Agency records list about 17 schools, colleges and universities with registered kitchens within about a mile and a half of Felden. Tell us your holiday dates and we will book the visit for when the site is empty.
Do you work overnight in Felden?
Yes, nights and weekends are routine for us. The site is handed back ready to open. Let us know the hours you’re closed and we will book within them.
What about areas you cannot get to?
They’re marked on the report. In ductwork, new access panels are often the answer, and we can fit those.
How long will the unit be out of action?
It takes anything from half a day for one small unit to several shifts for a plant room full of them. The unit’s size and condition make the biggest difference, and the quote will give you a clear idea.
Will we get paperwork for the AHU clean?
Yes, both a certificate and a report with photos. The report also suggests when the unit should next be inspected.
Are you fully insured?
Yes. Duct Doctor is fully insured, and the details are available on request.
What’s TR19?
BESA’s ventilation hygiene specification, with two parts that matter most here: TR19® Grease for kitchen extract systems and TR19® Air for general ventilation. It is not law, but it’s the benchmark.
How much notice should we give?
The more notice, the better, especially for out-of-hours work. We typically quote within one working day, and there’s a 24/7 line for emergencies.
Why act early in Felden
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. Dealing with it early keeps the clean straightforward. A planned visit to Felden fits your hours; an emergency does not.
Combining work into one visit or one programme can make for a more efficient booking. Mention every system or site you need covered, and you’ll get one fixed quote.
Why choose Duct Doctor in Felden
- Fixed quotes, normally within one working day
- Every job surveyed first
- A BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease
- One contact for all your sites in London and the South East