Air Conditioning, Ventilation and Refrigeration
AHU Maintenance
An air handling unit runs quietly in a plant room or on a roof until it stops, and by then it has usually been wasting energy for months and may have become a hygiene risk. A neglected unit costs money to run and can affect the air quality across the whole site.
Robinsons Facilities Services services and repairs commercial and industrial AHUs across Yorkshire and the Humber, using our own engineers and specialist partners, working to SFG20 maintenance schedules. We price per unit, so a site with several AHUs knows exactly where it stands.
Servicing from £250+VAT per unit, with multi-unit discounts | Annual contracts from £385+VAT/year per unit | Repairs from £80+VAT/hour
Get a quote for AHU maintenance →
Prefer to speak to someone? Call us on 01423 226578 →
An air handling unit (AHU) is the central component of a building’s ventilation system, drawing in, filtering, heating or cooling, and circulating air through ductwork. AHU maintenance covers filter changes, coil cleaning, belt and motor checks, and controls calibration, typically to SFG20 task schedules. High-use units need servicing quarterly; lower-use units annually.
What is an air handling unit?
An AHU is the central unit that conditions and circulates air around a building through ductwork. A typical unit contains fans, filters, heating and cooling coils, dampers, and controls. It draws in fresh air, filters out dust and contaminants, brings it to the right temperature, and distributes it through the building. Larger buildings often run several units serving different zones.
What AHU maintenance covers
A full AHU service inspects, cleans, and where needed replaces the components that keep the unit running safely and efficiently. A typical visit covers:
- Filter inspection and change: the single biggest factor in airflow and energy use
- Coil inspection and cleaning: heating and cooling coils, where fouling forces the system to work harder
- Fan, belt, and motor checks: inspection, tensioning, and lubrication
- Damper and actuator checks: confirming they move and seal correctly
- Controls and sensor calibration: so the unit responds correctly to demand
- Drainage and condensate checks
- Inspection for leaks, corrosion, and blockages
For hygiene-sensitive buildings, microbiological sampling and deep cleaning can be added, in line with current CIBSE Guide M guidance on ventilation hygiene. We agree the right scope with you based on the building type and how the unit is used.
How often should an AHU be serviced?
There is no single legal interval, but the recognised industry standard is SFG20, which sets maintenance task frequencies according to how the unit is used. The right frequency depends on the building:
- High-use units (offices, retail, healthcare, continuous operation): quarterly servicing, with more frequent filter changes
- Standard commercial units: typically serviced twice a year
- Lower-use units: at least annually
- Food and healthcare environments: hygiene-critical settings often require six-monthly cleaning under standards such as BRCGS
SFG20 is the framework insurers and health and safety auditors expect to see behind a maintenance contract. We build your schedule around it and keep the records that evidence compliance.
Why AHU maintenance matters
Two things make AHU maintenance worth more than it costs. The first is energy. A blocked filter or fouled coil forces the fans to work harder to move the same air, and that extra load shows up on every energy bill the unit runs. For a continuously running AHU, the wasted energy from neglect can outweigh the cost of a full year of planned maintenance.
The second is air quality and hygiene. Because the AHU conditions the air the whole building breathes, a contaminated unit can spread bacteria and mould through the ductwork. This is both a workplace health duty under the Health and Safety at Work etc. Act 1974 and, in food and healthcare settings, a serious compliance risk.
Pricing
We price AHU servicing per unit, because that’s how sites think about their plant. Cost per unit reduces where several AHUs are serviced in one visit.
Single AHU annual service from £250+VAT per unit
Full service and filter change per unit, with a written report. Multi-unit discounts apply where several units are serviced in one visit.
Get a quote for AHU maintenance →
Annual maintenance contract from £385+VAT/year per unit
Planned servicing scheduled to SFG20 frequencies, with priority response and preferential repair rates for contract customers.
Quarterly contract for high-use units typically £900 to £1,500+VAT per unit per year
Four planned visits a year for continuously running or hygiene-sensitive units, including more frequent filter changes. Priced per unit after we confirm the number and type of AHUs.
Filter-change visit from £150+VAT
A focused visit to change filters between full services, where a unit needs it. Priced per unit.
Repairs from £80+VAT/hour
Business-hours attendance to diagnose and repair a fault. Rate confirmed before the visit.
How we support you
On a PPM and compliance contract, we schedule each AHU to its SFG20 frequency, coordinate access to roof and plant-room units, and keep the maintenance records that satisfy insurers and auditors. For a single service or a one-off repair, we quote on-demand before we attend.
Contract customers also have access to our 24/7/365 out-of-hours call-out facility for ventilation failures affecting safety or operations. This is a separate service available to PPM contract customers only.
Robinsons Facilities Services is REFCOM registered, SafeContractor approved, and holds UKAS ISO 9001 certification. We maintain ventilation plant for offices, healthcare sites, manufacturers, and commercial property across Yorkshire, the Humber, and surrounding areas.
Get a quote for AHU maintenance →
Prefer to speak to someone? Call us on 01423 226578 →
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AHU Maintenance FAQs
AHU servicing from Robinsons Facilities Services starts from £250+VAT per unit, with multi-unit discounts where several units are serviced in one visit. Annual contracts start from £385+VAT/year per unit, and quarterly contracts for high-use units typically run £900 to £1,500+VAT per unit per year. The UK market generally runs £200 to £600 per unit per visit. Contact us or call 01423 226578 with the number and type of your units for a quote.
It depends on how the unit is used. Under SFG20 task schedules, high-use units in offices, retail, and healthcare are typically serviced quarterly, standard commercial units twice a year, and lower-use units at least annually. Filters usually need changing more often than the full service interval.
The recognised industry standard for maintenance task schedules is SFG20, which sets AHU service frequencies according to building use. For ventilation hygiene and cleanliness, current guidance is CIBSE Guide M. These are not laws in themselves, but they are the frameworks insurers and health and safety auditors expect to see behind a maintenance regime, and they help you meet your duty to maintain a safe workplace.
Hygiene-critical settings need more frequent attention than a standard office. In food manufacturing, standards such as BRCGS point to AHU cleaning around every six months, and healthcare environments have their own infection-control requirements. We agree a schedule that meets the relevant standard for your sector and keep the records to evidence it.
Yes, significantly. When filters clog and coils foul up, the unit has to draw more power to move the same air, and that extra consumption runs continuously. On a unit operating around the clock, the energy penalty from skipping maintenance can end up larger than what a planned maintenance contract would have cost in the first place.
AHUs are usually installed out of the way, commonly in a plant room, basement, or on the roof. Larger buildings often have several units serving different zones. Roof and high-level units may need access equipment to service safely, which we confirm when we quote.
Last updated: 21/07/2026
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