Hertfordshire · Air handling unit cleaning
Tewin AHU cleaning
One call covers AHU cleaning in Tewin: survey, fixed quote, work and sign-off. CHAS and SafeContractor accredited, ISO 9001 and fully insured.
- Dust built up on fan impellers
- Units that have only ever had filter changes
- Dust-coated heating and cooling coils
What AHU cleaning can’t fix
An honest diagnosis matters more to us than a booking, so here’s what this work can’t put right:
- Dirty ducts beyond the unit itself
- Faulty motors, drives or bearings
- Airflow problems caused by the system’s design
Not sure which it is? You can phone us on 0345 646 2711 or use the quote form and we’ll tell you honestly before you book.
Parts of the system we cover
- Supply and extract fans
- Filter sections
- Internal panels
- Drain trays
- Dampers and louvres
- Heating and cooling coils
How we handle AHU cleaning in Tewin
Units vary a lot in size, age and layout, from a small ceiling-mounted unit to a large rooftop plant. Every job starts with a survey, from pictures or on site, followed by a fixed quote, so you know where you stand. The work covers heating and cooling coils, dampers and louvres and internal panels, and common reasons people get in touch are debris and leaves in the fresh air intake and blocked condensate drains and slimy trays.
Work in a small place like Tewin starts with agreeing access and timings, and the ventilation is inspected, cleaned and recorded the same as anywhere.
The sign-off is always in writing: a written report, dated and illustrated with pictures, and for TR19® Grease cleans, a certificate issued through the BESCA VHE portal. Any parts we couldn’t reach are recorded on it too.
- Location
- Tewin (AL6)
- Region
- Hertfordshire
- Reporting
- Report and photos after the visit
- Quote
- A fixed quote up front
- Working hours
- After hours by arrangement; emergencies any time
- Call
- 0345 646 2711
- Checked
- 30 October 2026
What we are called out for in Tewin
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 the finer material travels on.
Signs it’s time to call us include:
- Odours coming through the supply air
- Intake sections clogged with outdoor debris
- Dirty coils holding back the airflow
- Filters that are clogged or overdue
If you run a surgery, dental practice or care home near Tewin, clean ventilation matters as much to you as to a hospital like Queen Elizabeth II Hospital (about 2.8 miles south-west).
Comparing quotes
- How they set the interval to the next visit
- What records you will receive afterwards
- Whether a survey comes first
- When they can work, and whether that’s outside your opening hours
What the work involves, part by part
Drain trays
Standing water in a tray sits right where the air passes. We clean it and report anything about the tray or drain that needs fixing.
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.
Other services in Tewin
The process
On the day, we arrive at the time agreed with you, often in the evening, overnight or at the weekend so the site keeps working. Equipment that has to be off is switched off and allowed to cool first, and floors and nearby surfaces are sheeted. On site, it takes a single shift for a typical unit, longer for large or heavily soiled ones. If the van will struggle with a lane or gateway near Tewin, let us know and we’ll plan around it.
- First we agree when the unit can be switched off, including evenings or weekends.
- We take before pictures of each section of the unit.
- Filters, coils and internal surfaces are cleaned from intake to discharge.
- The fan and drain tray are cleaned and the drain checked.
- We take after photos and issue the certificate and report.
Getting ready for the visit
- Mention any locked doors, roof access or ceiling voids
- Let us know when the site is closed or quiet
- Tell us about site rules, permits or sign-in
How to get a quote
To help us quote: where the site is, what it is and its opening hours, a few photos and any previous report or certificate. Once you have those, call us on 0345 646 2711 or email us.
Advice
What happens if it’s left?
Standing water in a drain tray does not 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. Rural sites can’t always move to another kitchen or room when something fails.
Putting the work off seldom saves money. Build-up, wear and faults tend to get worse, not better, which can make the next visit longer. If you’re unsure, call us on 0345 646 2711, or send details by email for straight advice and a fixed quote.
Why book with us
- Fully insured
- BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease
- Trading since 2009
- A single point of contact for sites across the South East and London
Take a look at what affects the cost or our accreditations and certificates.
In-house cleaning or a specialist?
Staff cleaning does not replace a specialist visit; it supports it. Clean filters and tidy surfaces slow the build-up, but the parts you can’t see still need a specialist at the right interval.
Staff cleaning and specialist work aren’t the same thing. Wiping filters daily and washing them weekly keeps the visible parts in order, but grease that has passed the filters is out of reach. That part needs specialist access and equipment.
AHU cleaning around Tewin
Going by the FSA’s register, there are about 5 schools, colleges and universities serving food in and around Tewin, up to about a mile and a half out. Buildings like these often rely on mechanical ventilation, which TR19® Air covers. About 2.8 miles south-west of Tewin is Queen Elizabeth II Hospital, the nearest hospital. Healthcare ventilation is a good example of why supply ducts need inspecting: the air goes straight to patients. At about 22 miles from central London, Tewin sits well inside the area we cover. Visits are booked around your hours, evenings and weekends included.
Classrooms and halls at schools such as Ridgeway Academy are easiest to work in when pupils are away.
Tewin is about 2 miles north-east of Welwyn Garden City, in Hertfordshire. Every kind of commercial site in Tewin, we can take on AHU cleaning. We can work out of hours so trading isn’t interrupted. Tewin is one of 381 places in Hertfordshire we cover for commercial clients. You can also see our page for London, roughly 22 miles from Tewin.
Work in AL6 is surveyed, quoted and booked the same way as anywhere else. That includes premises on Upper Green Road, Godfries Close and Harwood Close and the roads around them. Close by, we work in Tewin Wood (1 mile north), Burnham Green (1 mile north-west), Harmer Green (1 mile north-west), Haldens (1 mile west) and Bramfield (1 mile east). We also work in nearby towns such as Watford (15 miles south-west), Hemel Hempstead (14 miles west), Stevenage (6 miles north), St Albans (9 miles south-west), Bishop's Stortford (14 miles east) and Harpenden (8 miles west).
Around Tewin
Locally, jobs take us to businesses close to Rose And Crown Public House and Panshanger Park, among other places. The nearest railway station is Welwyn North station, roughly 1.6 miles west. Other landmarks nearby include Howard Centre (2.4 miles south-west) and Queen Elizabeth II Hospital (2.8 miles south-west). The countryside around Tewin includes Tewin Orchard and Hopkyns Wood.
Keeping the system healthy
Good habits slow the build-up between visits. A few tips:
- Report water on the plant room floor
- Change filters on schedule and log each change
- Keep the area around the fresh air intake clear
- Book the next check in line with the report
The report suggests a date for the next inspection or clean, based on what we found. TR19® Air is risk-based, so the interval depends on the unit and how the building is used.
Change or clean filters on time. Once filters clog, dirt starts getting past them.
Your questions about AHU cleaning in Tewin
Do you cover smaller places like Tewin?
Yes. Villages and rural sites across the South East are part of our work, Tewin included. Just mention lanes, gates or anything else about the site when you book.
Do you work overnight in Tewin?
Yes, out-of-hours work is a big part of what we do. That way a site in Tewin does not have to lose a day’s trading. Tell us your opening hours when you ask for a quote.
Is there a survey before the work?
Yes, every time. We diagnose before we treat: the survey shows what needs doing and what access we need and the fixed quote is built on it.
Where does the waste go?
Anything we remove is contained as we work and taken away with us, from grease and debris to used cleaning water. We don’t leave it behind.
Which kinds of sites do you work on?
All kinds of commercial and public premises: from restaurants, pubs and hotels to schools, hospitals, care homes, offices, shops and food production sites. We fit the work around how the site operates.
How often should an air handling unit be cleaned?
Inspection under TR19® Air decides it. Units in heavy use or in sensitive buildings may need attention more often.
How far ahead should we book?
That depends on the slot you want and the size of the job. Tell us your preferred dates when you ask for a quote, and if it’s an emergency, call us any time.
Do you do ventilation duct cleaning too?
Yes, supply and extract ducts, grilles and diffusers. The survey shows whether the ducts need cleaning now.