Hertfordshire · Air handling unit cleaning
AHU Cleaning in Tewin Wood
Cleaning of air handling units, including filters, coils, drain trays, fans and internal surfaces for commercial sites in Tewin Wood and across Hertfordshire. CHAS, SafeContractor and ISO 9001, and fully insured.
- Blocked condensate drains and slimy trays
- Dirty coils holding back the airflow
- Units needing a clean before a new tenant or handover
Why deal with it now?
Dirt left in an air handling unit does not stay in the unit. It moves on into the ductwork and out into the rooms, so cleaning the ducts without the unit only goes so far. With notice, the visit to Tewin Wood can be fitted around your bookings and events.
Several systems or sites on one quote often makes better use of the time. Mention every system or site you need covered, and you will get one fixed quote.
Why book with us
- One number for every site across the South East and London
- Evenings, overnight and weekends, plus 24/7 emergency callout
- In business since 2009
- Survey first, then a fixed quote
Read our cost guide and our accreditations and certificates.
AHU cleaning in Tewin Wood, done properly
Think of an AHU clean as a full check-up for the ventilation. We look inside each section, clean what we find and record it with pictures, so you can see the unit’s condition for yourself. If you have blocked condensate drains and slimy trays and filters that are clogged or overdue, we can help.
Work in a small place like Tewin Wood starts with agreeing access and timings, and the ventilation is inspected, cleaned and recorded the same as anywhere.
Accreditations are easy to claim and worth checking. We’re a BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease, and we hold CHAS, SafeContractor and ISO 9001, with full insurance on top.
- Place
- Tewin Wood (AL6)
- Region
- Hertfordshire
- Reporting
- Photo report after every visit
- Price
- Fixed quote, normally within a working day
- When we work
- After hours by arrangement; emergencies any time
- Call
- 0345 646 2711
- Last updated
- 30 October 2026
Honest limits
An honest diagnosis matters more to us than a booking, so here’s what this work cannot put right:
- A system that is undersized for the building
- Dirty ducts beyond the unit itself
- Building management system faults
Not sure which it is? You can give us a ring on 0345 646 2711, or email photos and we will tell you honestly before you book.
Parts of the system we cover
- Supply and extract fans
- Dampers and louvres
- Internal panels
- Heating and cooling coils
- Filter sections
- Drain trays
What the work involves, part by part
Heating and cooling coils
Cooling coils stay damp in use, so dirt on them can turn sticky. The coil and its drain tray are cleaned as one job.
Internal casing and panels
Access doors and panels are opened in turn and closed properly afterwards, and check every one is shut.
Aftercare tips
Good habits slow the build-up between visits. A few tips:
- Report water on the plant room floor
- Store the TR19 paperwork where auditors can find it
- Make sure condensate is draining away
- Report stiff or damaged access doors
When we have closed the unit up, it can be restarted with your site team. Keep an eye on the condensate drain over the next few days to make sure it stays clear.
Keep the area around the intake clear. What’s near the intake ends up in the unit.
Places near Tewin Wood
What else we do in Tewin Wood
What happens on the day
We start by comparing what we find with the survey or your pictures. If anything is different, we talk it through with the person on site before carrying on. From there, it takes a single shift for a typical unit, longer for large or heavily soiled ones. For a village or hamlet like Tewin Wood, tell us about narrow lanes, gates and parking when you book.
- First we agree when the unit can be switched off, including evenings or weekends.
- Before cleaning, each section is photographed.
- 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 pictures and issue the certificate and report.
Getting ready for the visit
- Arrange a key holder or contact on site
- Agree a time when the area can be out of use
- Mention any parking or loading restrictions
Getting a quote
Quoting starts with a diagnosis, either from photos and details you send or from a site visit. After that, you get a fixed price for the work, before we start.
Read more
Tewin Wood: your questions answered
Will you come out to Tewin Wood?
Yes, Tewin Wood is part of our area, however small the site. The journey is planned ahead, so a few details about the route help.
Can the work in Tewin Wood be done at night or at weekends?
Yes, out-of-hours work is a big part of what we do. That way a site in Tewin Wood does not have to lose a day’s trading. Let us know the hours you are closed and we will book within them.
How do you keep the site clean during the work?
We start with protection: floor sheeting and covers over nearby surfaces and equipment. The area is left tidy, with our waste taken away.
Do you look at the system first?
Yes. For many sites, photos and a few details are enough, while bigger or harder-to-see systems are surveyed on site.
Do you do ventilation duct cleaning too?
Yes, the ductwork, grilles and diffusers the unit serves. We’ll tell you after the survey whether the ducts need it.
Can you quote from photos?
Yes, if we can see what we need. Otherwise, we book a survey at a time that suits the site, then a fixed quote.
What happens if you can’t reach some of it?
We never leave them off the paperwork. The report says which parts couldn’t be reached and why, along with a quote to put access in.
Do you offer maintenance contracts?
Yes. Regular plans can run on 3, 6 or 12-monthly cycles, depending on what the system needs.
When to call us in Tewin Wood
Air handling units are usually tucked away on roofs, in plant rooms or above ceilings and are rarely seen by anyone but maintenance staff. It’s easy for a long time to go by without anyone opening the panels.
Look out for any of the following:
- Fan sections that haven’t been cleaned in years
- Air handling units due a clean after building work
- Condensate trays that won’t empty
- Dirty coils holding back the airflow
Healthcare buildings such as Queen Elizabeth II Hospital, about 3.5 miles south, depend on their ventilation; if you manage a surgery, clinic or care home near Tewin Wood, yours matters too.
What to look for in a quote
- What paperwork you get at the end
- What’s included in the scope, part by part
- Whether VAT is included
- Which accreditations they hold, and whether you can check them
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.
In-house cleaning and specialist cleaning do different jobs. 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.
Tewin Wood buildings and their air
The FSA’s food hygiene register lists about 3 schools, colleges and universities with registered kitchens or food service within 1.5 miles or so of the middle of Tewin Wood. Buildings like these often rely on mechanical ventilation, which TR19® Air covers. About 3.5 miles south of Tewin Wood is Queen Elizabeth II Hospital, the nearest hospital. Healthcare buildings depend on clean supply and extract ventilation, and the same applies to surgeries, clinics and care homes. About 23 miles out from central London, Tewin Wood is part of the South East area we work across. The visit is fixed around your opening hours, not ours.
Classrooms and halls at schools such as Ridgeway Academy are easiest to work in when pupils are away.
Tewin Wood is about 3 miles north-east of Welwyn Garden City, in Hertfordshire. Every kind of commercial site in Tewin Wood, we can take on AHU cleaning. We can work out of hours so the site keeps running. Across Hertfordshire, we cover 381 places, and Tewin Wood is one of them. For sites nearby, see our London page (23 miles or so).
Every address in AL6 is covered for AHU cleaning, from the main roads to the quietest streets. Whether your site is on Cowpers Way, Desborough Drive and Firs Walk or a nearby road, our technicians can take on the work. Nearby, we also carry out AHU cleaning in Burnham Green (1 mile north-west), Bull's Green (1 mile north), Harmer Green (1 mile west), Tewin (1 mile south) and Datchworth (1 mile north). Larger places within reach include Watford (15 miles south-west), Hemel Hempstead (14 miles south-west), Stevenage (5 miles north), St Albans (9 miles south-west), Bishop's Stortford (14 miles east) and Welwyn Garden City (3 miles south-west).
Near you in Tewin Wood
In Tewin Wood, that means kitchens and buildings near Belmont pub. The nearest railway station is Welwyn North station, about 1.4 miles west. Nearby you will also find Howard Centre (2.8 miles south-west) and Hertford Castle (4.3 miles south-east). Open spaces near Tewin Wood include Tewin Orchard and Hopkyns Wood.