Hertfordshire · Air handling unit cleaning
Northaw AHU cleaning
AHU cleaning across Northaw and nearby, booked around your opening hours and finished with a written report and pictures.
- Stale or musty smells from the ventilation
- Units that have only ever had filter changes
- Air handling units with blocked filters
AHU cleaning in Northaw, done properly
Drain trays under cooling coils are meant to empty. If the outlet blocks, standing water and slime build up, right in the path of the air going into the building. Cleaning and clearing it is a key part of the job. Common call-outs are for dirty coils holding back the airflow and plant that has been serviced but not cleaned, across filter sections, internal panels and dampers and louvres.
Work in a small place like Northaw starts with agreeing access and timings.
We’re CHAS and SafeContractor accredited, we hold ISO 9001 and we’re fully insured. We are also a BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease, and we have been trading since 2009.
- Location
- Northaw (EN6)
- Wider area
- Hertfordshire
- Paperwork
- Photo report after every visit
- Quotes
- Fixed quote, usually within a working day
- When we work
- Out of hours as standard, 24/7 emergency line
- Telephone
- 0345 646 2711
- Checked
- 30 October 2026
What affects the cost of AHU cleaning
There’s no set price list, because sites vary so much. The quote depends on:
- How many systems or sites are involved
- Whether we need access equipment or extra panels
- What state the system is in
- Whether it’s a one-off visit or part of a schedule
When the work has to happen, how we reach it and how big the site is can all change the price. We take each of them into account, and the price is fixed before any work starts.
What to send for a quote
What to send for a quote:
- The site address and the type of premises
- Anything you’ve noticed, such as smells, noise, drips or poor airflow
- Wide photos of the system and the area around it
- Your opening hours and when the area is out of use
For a fixed quote, call us on 0345 646 2711, or email photos with the site type, your trading hours and a short description of the system. A few pictures and your last certificate or report help a lot. You will typically have a quote within one working day.
Part by part
Filters
What’s on the filters is a good clue to what’s further in. They’re photographed before and after for your records.
Fans and fan sections
Before the fan is touched, the unit is shut down and made safe with your site team.
Staff cleaning versus specialist work
If your staff spot something between visits, like drips, unusual noise, smells or damaged filters, it’s best reported rather than tackled in-house. We’ll take a look and send you a fixed quote.
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. Reaching it takes a specialist with the right equipment.
Common problems we fix in Northaw
Wherever there’s a cooling coil, there’s condensate. If the drain tray outlet blocks or the tray doesn’t fall properly, water stands in it, and that’s where slime and odours start.
Clients typically contact us when they notice something like this:
- Leaves and litter drawn into the unit
- Drain trays holding standing water
- Stale or musty smells from the ventilation
- Units needing a clean before a new tenant or handover
If you run a surgery, dental practice or care home near Northaw, clean ventilation matters as much to you as to a hospital like Chase Farm Hospital (about 3.3 miles south-east).
Questions to ask before booking
- Whether the quote is based on a survey or pictures
- How VAT is shown on the quote
- Whether they recommend a next date
- Whether they’re fully insured
Northaw questions
Can you clean school ventilation in Northaw during the holidays?
Yes, and it’s the easiest time to do it. With about 8 schools and colleges on the FSA’s register within roughly a mile and a half of Northaw, it pays to plan holiday dates ahead. Booking early in the term gives the best choice of holiday dates.
Can you come to Northaw after we close?
Yes, out-of-hours work is a big part of what we do. That way a site in Northaw does not have to lose a day’s trading. Your opening times are the first thing we ask for.
What about areas you cannot get to?
They’re listed in the report, never skipped quietly. You will know exactly which parts weren’t reached and why, along with a quote to put access in.
Which kinds of sites do you work on?
Commercial premises of every kind: kitchens, offices, schools, healthcare, retail, leisure and food production. We fit the work around how the site operates.
How much notice should we give?
Earlier is better, particularly for night and weekend visits. Quotes normally come back within one working day, and emergencies are covered by our 24/7 line.
Are you insured?
Yes. Duct Doctor is fully insured, and the details are available on request.
How much does AHU cleaning cost in Northaw?
We don’t publish prices, because the cost depends on the job: how big it is, what state it’s in, how we reach it and the working hours. We fix the price before we start.
What do you do to protect the area?
Protection goes down first: sheeting over floors, worktops and anything close to the work. We tidy up and take our waste away before we leave.
What happens on the day
Our technicians bring everything the work needs, from protective sheeting to tools and access equipment. All we need from you is clear access and the right equipment switched off. The visit takes half a day to a full day per unit, with large plant planned over several shifts. If you can send photos, we can arrive in Northaw knowing what to expect.
- We look at the unit and the plant area during the survey.
- We sheet the area and the unit is isolated.
- Each section is cleaned of dust, debris and slime.
- We clean the coils and clear the tray and drain.
- The unit is closed up and handed back, with a report to follow.
Before we arrive
- Mention any parking or loading restrictions
- Arrange a key holder or contact on site
- Let us know about permits to work or site inductions
Getting a quote
Some systems can be priced from photos; others need a survey. Big or complicated sites, and systems that are hard to see in pictures, get a survey first. Either way, you get a fixed price before we start.
Related advice
Honest limits
Before booking, it helps to know what’s not included:
- Building management system faults
- Ductwork downstream of the unit, which is a separate clean
- Coils that are corroded or leaking and need replacing
If in doubt, call us on 0345 646 2711, or email photos and we’ll say what we think.
Parts of the system we cover
- Internal panels
- Drain trays
- Filter sections
- Supply and extract fans
- Dampers and louvres
- Heating and cooling coils
Landlords, agents and facilities managers
Facilities teams in offices, schools and healthcare sites book us too in Northaw and across Hertfordshire. Larger estates can be phased building by building to keep disruption down.
Landlords, managing agents and facilities managers book us, not only the businesses that use the systems. Where a system serves more than one tenant, such as a shared riser, it helps to agree who arranges the work, and we can quote for the whole system.
What AHU cleaning looks like in Northaw
Food Standards Agency data includes about 8 schools, colleges and universities and about 6 caring premises (care homes, nurseries and hospitals) within about 1.5 miles of central Northaw. Classrooms, bedrooms and care spaces are often served by ducted air, and that ductwork collects dust over time. Northaw is about 14 miles from central London, well within the area we cover across London and the South East. A survey and a fixed quote come first, then the visit at a time that suits you. The nearest hospital to Northaw is Chase Farm Hospital, about 3.3 miles south-east. Hospitals show how much a building can rely on its ventilation, and smaller healthcare sites rely on theirs too.
School buildings such as Northaw Church of England Primary School are typically done in the holidays, so classrooms are not disturbed.
Northaw is about 2 miles north-east of Potters Bar, in Hertfordshire. For AHU cleaning in and around Northaw, please call 0345 646 2711, or email photos for a fixed quote. Our area covers London and the South East, Northaw included. Across Hertfordshire, we cover 381 places, Northaw among them. Our London page covers sites nearby (14 miles or so).
Here we cover the EN6 postcode area for AHU cleaning. That includes premises on Vineyards Road, Church Lane and Northaw Road West and nearby roads. We also cover the places around Northaw: Cuffley (1 mile east), Brookmans Park (2 miles north-west), Newgate Street (2 miles north-east), Bell Bar (2 miles north-west) and Little Berkhamsted (3 miles north). Within a short drive, we also cover Watford (11 miles west), Hemel Hempstead (14 miles west), Stevenage (14 miles north), St Albans (8 miles west), Welwyn Garden City (7 miles north) and Harpenden (12 miles north-west).
Around Northaw
Locally, jobs take us to businesses close to Two Brewers Public House and Mount Grace School and the streets around them. The closest station to Northaw is Cuffley station, about 1.6 miles east of the centre. A little further out are Potters Bar Museum (2.1 miles west) and Chase Farm Hospital (3.3 miles south-east). For a walk, there’s Fir and Pond Woods.