Hertfordshire · Air handling unit cleaning
Harmer Green AHU cleaning
Cleaning of air handling units, including filters, coils, drain trays, fans and internal surfaces for commercial sites in Harmer Green and across Hertfordshire. BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease.
- Air handling units with blocked filters
- Plant that needs cleaning after a refit
- Fan sections that haven’t been cleaned in years
FAQs for Harmer Green
Can you work in Harmer Green outside opening hours?
Yes, out-of-hours work is a big part of what we do. The work in Harmer Green can fit around your hours. Your opening times are the first thing we ask for.
Do you work in villages like Harmer Green?
Yes, we work in villages as well as towns, and Harmer Green is covered. A survey first, from pictures or a visit, means we arrive with the right kit.
Are you insured?
Yes. Full insurance covers our work, and we’ve been trading since 2009.
Where does the waste go?
Waste is contained during the work and removed when we leave, from grease and debris to used cleaning water. We do not leave it behind.
What information do you need?
Only a few details: where it is, what kind of site, when it’s open and the access. Photos and any previous paperwork make it quicker. Then call us on 0345 646 2711 or send us an email.
What’s TR19?
A BESA specification, with two parts that matter most here: TR19® Grease for kitchen extract systems and TR19® Air for general ventilation. It isn’t law, but it’s the benchmark.
What’s included in an AHU clean?
We clean the filter section, heating and cooling coils, drain trays, fan and internal casing. What happens to the filters is agreed when we quote.
Do you offer emergency callouts?
Yes, 24/7. Office hours are Monday to Friday, 8am to 6pm, with the emergency line covering every other hour.
About our AHU cleaning in Harmer Green
If the units serving a building in Harmer Green have only had filter changes for years, there may be dirt on the coils, fan and casing that nobody has looked at. A full clean deals with all of it. Common call-outs are for dust-coated heating and cooling coils and intake sections clogged with outdoor debris, on drain trays, supply and extract fans and internal panels.
Rural buildings with mechanical ventilation, such as care homes and country hotels, often keep their units in roof spaces or outbuildings, which makes them easy to overlook.
A written report with photos follows every visit, so you have a record of what was done and when. Kitchen extract cleaning to TR19® Grease is certificated through the BESCA Vent Hygiene Elite portal.
- Place
- Harmer Green (AL6)
- Wider area
- Hertfordshire
- Records
- Photo report after each visit
- Quotes
- A fixed quote up front
- Hours
- Nights, weekends or holidays to suit you
- Telephone
- 0345 646 2711
- Checked
- 30 October 2026
Also near Harmer Green
Other services in Harmer Green
Different parts, different methods
Drain trays
A tray that doesn’t drain becomes a pool of stagnant water in the airstream. We clean it and note if the slope or the drain needs attention.
Fans and fan sections
Before the fan is touched, the unit is shut down and made safe in agreement with the site.
What we do, step by step
There are three stages on the day: set-up, the treatment itself and the sign-off. Set-up means sheeting and making equipment safe, and the sign-off is a written report with photos. The middle part takes longest, which takes half a day to a full day per unit, with large plant planned over several shifts. Rural roads and tight entrances are worth telling us about before a visit to Harmer Green.
- The survey covers the unit, its access and how it can be shut down.
- 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.
Before we arrive
- Have your last certificate or report to hand
- Tell us about access, such as roof hatches, plant rooms, ceilings or locked areas
- Plan for cooking equipment or plant to be off before we arrive
Getting a quote
If you need AHU cleaning in Harmer Green, call us on 0345 646 2711, or send details by email. Tell us what kind of premises it is and when it’s open, and send pictures or your last report if you can. We typically send a fixed quote within one working day.
Advice
AHU cleaning around Harmer Green
Food Standards Agency records list about 10 schools, colleges and universities and about 8 hospitals, care homes and childcare premises registered as food businesses within roughly a mile and a half of the centre of Harmer Green. Classrooms, bedrooms and care spaces are often served by ducted air, and that ductwork collects dust over time. Harmer Green is about 23 miles from central London, well within the area we cover across London and the South East. Visits are booked around your hours, evenings and weekends included. The nearest hospital to Harmer Green is Queen Elizabeth II Hospital, about 3.4 miles south. Healthcare ventilation is a good example of why supply ducts need inspecting: the air goes straight to patients.
If you manage offices or shops near Welwyn North station, their ventilation can be inspected and cleaned out of hours. For schools like Oaklands Primary School, the holidays are the usual time to inspect and clean ventilation. Queen Elizabeth II Hospital, about 3.4 miles south, is the nearest hospital to Harmer Green, and healthcare sites of every size need their supply air kept clean.
Harmer Green is about 2 miles north of Welwyn Garden City, in Hertfordshire. For AHU cleaning in and around Harmer Green, please give us a ring on 0345 646 2711, or send details by email for a fixed quote. Our area covers London and the South East, including Harmer Green. Harmer Green is one of 381 towns, villages and districts in Hertfordshire where we work for AHU cleaning. London is in our area too, around 23 miles away.
We work across AL6 for AHU cleaning and the streets around it. We also cover the places around Harmer Green: Burnham Green (1 mile east), Tewin Wood (1 mile east), Oaklands (1 mile north-west), Bull's Green (1 mile north-east) and Digswell (1 mile south-west). Larger places within reach include Watford (15 miles south-west), Hemel Hempstead (13 miles south-west), Stevenage (5 miles north), St Albans (8 miles south-west), Bishop's Stortford (15 miles east) and Harpenden (7 miles west).
Near you in Harmer Green
We work in commercial kitchens and buildings around Danesbury Park, Monk's Walk School and The White Horse Public House, among other places. For rail, the closest station is Welwyn North station, about 0.8 miles south-west of the centre. Other landmarks nearby include Hertford Castle (4.9 miles south-east) and Queen Elizabeth II Hospital (3.4 miles south). Open spaces near Harmer Green include Tewin Orchard and Hopkyns Wood.
Leave it or put it right?
Leave an AHU uncleaned and the dirt doesn’t stay put. It’s carried through the ductwork and out of the grilles, which is why the unit and the ducts are best cleaned together. Planning a trip to Harmer Green ahead is easier for everyone than a rushed one.
A single site or a whole portfolio, the quote is built the same way: what needs doing, how we get to it and when. You will have a fixed price before any work starts.
What you get with us
- Fixed quotes, normally within one working day
- Every job surveyed first
- Trading since 2009
- Fully insured
Read our cost guide or how to check a contractor.
In-house cleaning or a specialist?
Some jobs should never be done in-house: entering ducts, working on fans, testing dampers and taking grease readings call for the right kit, training and safe access. Leave those to us.
Staff cleaning and specialist work are not the same thing. Wiping filters daily and washing them weekly keeps the visible parts in order, but they do not reach the grease that builds up further in. Reaching it takes a specialist with the right equipment.
Looking after it afterwards
Here’s the after-treatment advice, in brief:
- Change filters on schedule and log each change
- Keep inspection doors on the unit in good order
- Watch for drips or damp patches near the plant
- Diary the inspection date recommended in the report
You receive a TR19® certificate and a photo report after the clean. Keep both with the building’s maintenance records.
Have the unit inspected regularly, in line with the risk-based approach of TR19® Air instead of leaving it to guesswork.
For landlords and multi-site operators
Where a tenant occupies the premises but the landlord owns the building, it’s worth checking the lease for who maintains the systems. We can quote either party and send the paperwork to whoever needs it.
Multi-site operators often want one contractor and one number. We work across London and the South East, so a run of sites can go into one programme and kept on a regular cycle.
Honest limits
Some problems need a different service or another trade:
- Airflow problems caused by the system’s design
- Dirty ducts beyond the unit itself
- Controls and BMS settings that run the unit
Not sure which it is? You can call 0345 646 2711 or email us and we’ll tell you honestly before you book.
What we work on in Harmer Green
- Heating and cooling coils
- Dampers and louvres
- Filter sections
- Supply and extract fans
- Internal panels
- Drain trays