PLANT & MACHINERY / AIR HANDLING
AHU and FCU filter monitoring
Stop changing clean filters and running blocked ones
A ducted air-conditioning estate contains hundreds of disposable filters, and almost every site changes them on a fixed cycle, typically quarterly, because there is no way to know which are actually loaded. That guarantees two failures at once. Filters in clean, lightly used zones are thrown away with most of their life left, which is pure spend on consumables and labour. Filters in dirty or heavily used zones blind up long before the next visit, so fans work harder against the resistance, energy use climbs, airflow to the space drops and occupants complain about a building that is quietly running below design. The one measurement that resolves it, pressure drop across the bank, is standard practice in the standards and almost never actually instrumented.
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The difference
Ahu filter monitoring: what changes the day it goes live
A ducted air-conditioning estate contains hundreds of disposable filters, and almost every site changes them on a fixed cycle, typically quarterly, because there is no way to know which are actually loaded. That guarantees two failures at once. Filters in clean, lightly used zones are thrown away with most of their life left, which is pure spend on consumables and labour. Filters in dirty or heavily used zones blind up long before the next visit, so fans work harder against the resistance, energy use climbs, airflow to the space drops and occupants complain about a building that is quietly running below design. The one measurement that resolves it, pressure drop across the bank, is standard practice in the standards and almost never actually instrumented.
- Differential pressure across each filter bank, so a change is triggered by actual loading rather than by a date in a maintenance calendar
- Consumables and labour spent on the filters that need changing, which on a large estate usually means fewer visits producing better air
- Fan energy protected, because a blinded filter that would have run for weeks against high resistance is caught in days
- Evidence that design airflow is being maintained, which matters for ventilation compliance as much as for comfort
What you get
- 01
Differential pressure across each filter bank, so a change is triggered by actual loading rather than by a date in a maintenance calendar
- 02
Consumables and labour spent on the filters that need changing, which on a large estate usually means fewer visits producing better air
- 03
Fan energy protected, because a blinded filter that would have run for weeks against high resistance is caught in days
- 04
Evidence that design airflow is being maintained, which matters for ventilation compliance as much as for comfort
The full stack, applied here
All five layers, one accountable system
Every Indiott build runs all five layers as one accountable system. Follow a single live signal from the sensor that catches it to the report that proves it.
Turnkey LoRaWAN and industrial sensors read the physical world at the edge, on battery, without rewiring the site.
Hands a reading to CONNECT ↓
Gateways, industrial routers and serial device servers carry every reading back over LoRaWAN, 4G, 5G, Ethernet or satellite, so the far edge reports as reliably as the plant room.
Hands a signed stream to SECURE ↓
OT security by design: managed switching, VPN and firewall routers, protocol gateways and hardware data diodes keep the network segmented and the data tamper-evident to IEC 62443.
Hands a trusted stream to CONTROL ↓
When you want the system to act, remote IO, wireless valves and the bespoke Indiott Engineering line close the loop, dose, switch, isolate or interlock, with no human in the middle.
Hands an action to MANAGE ↓
The software layer turns it into decisions: live dashboards, mapping, alarming and analytics, with one-tap reports and clean feeds into your SCADA, BMS or existing platform.
The loop is closed ✓
How teams start
From a single pilot to the whole portfolio
You do not boil the ocean. Nearly every rollout runs the same four moves, and you own a working, evidenced result at the end of the first one.
Scope & risk map
We walk the sites, list the assets and pin the one constraint that matters, then agree what a good result looks like before a single sensor is bought.
Pilot on one site
A focused set of sensors goes onto one site or asset group, live on our telemetry and dashboards, wired to the people who need the alert.
Validate & standardise
We tune thresholds, kill false positives, confirm the integration into your SCADA, BMS or CAFM, and write the standard design down so it repeats.
Scale the portfolio
The proven design rolls out across the estate, reusing the same hardware standards and data models so every site reads the same way.
The ahu filter monitoring kit we deploy
Full catalogue
Urban.io Activity Sensor
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Urban.io Ambient Temperature Sensor
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Urban.io Battery Test Sensor
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Urban.io Current Sensor
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Urban.io Delta Pressure Sensor
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Urban.io Gateway
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Urban.io Humidity Sensor
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Urban.io Light Sensor
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| Model | Key specification | Price ex VAT | Availability |
|---|---|---|---|
| Urban.io Activity Sensor | — | Price on request | Quote only |
| Urban.io Ambient Temperature Sensor | — | Price on request | Quote only |
| Urban.io Battery Test Sensor | — | Price on request | Quote only |
| Urban.io Current Sensor | — | Price on request | Quote only |
| Urban.io Delta Pressure Sensor | — | Price on request | Quote only |
| Urban.io Gateway | — | Price on request | Quote only |
| Urban.io Humidity Sensor | — | Price on request | Quote only |
| Urban.io Light Sensor | — | Price on request | Quote only |
Brands in this kit: Urban.io
Why Indiott
A specialist stack, not a box-shifter
Brand-agnostic by design
We pick the best of each brand for the layer and the environment, not one vendor catalogue. Milesight, AquaIoT, Atop, Browan, SpecSens and Urban.io, chosen on merit.
The whole stack, one supplier
Sensing, connectivity, OT security, control and the dashboard come from one accountable team, so there is no finger-pointing when something needs to talk to something else.
Specified and supported in Britain
UK-based engineers scope the site, quote the kit and stand behind it, with compliance mapped to the regimes your auditors actually cite.
Honest kit, honest pricing
Prices are shown where we can, quoted fast where we cannot, and you get a straight answer and a bill of materials within one working day.
DEPLOYED IN THE FIELD
Compliance this answers to
| Standard | What it requires |
|---|---|
| CIBSE TM44 | measured filter condition and airflow evidence strengthens statutory air-conditioning inspections |
| BS EN 16798 / CIBSE Guide B | maintaining design airflow supports the ventilation rates the building was designed to deliver |
| Workplace (Health, Safety and Welfare) Regulations 1992 | effective and suitable ventilation is a duty, and pressure data evidences it |
What it costs, roughly
One delta pressure sensor per filter bank, sharing a gateway across the plant room or building, puts a monitored AHU in the low hundreds of pounds. On an estate changing filters quarterly across dozens of units, the consumables and labour avoided usually cover the sensors well inside the first year. We will model that against your actual filter spend rather than quoting a generic payback.
Ahu filter monitoring: asked before buying
What pressure threshold should trigger a change?
Use the filter manufacturer's final resistance figure for that grade, not a generic number. A typical bag filter might start around 50 to 90 Pa clean and be considered spent somewhere near 250 Pa, but that varies by grade and face velocity, so we set the threshold per unit from your actual filter spec. Setting one number across a mixed estate is the usual mistake.
Can it go on fan coil units as well as big AHUs?
Yes, though the economics differ. On a large AHU with expensive filters and a big fan, per-unit monitoring is easy to justify. Across hundreds of small FCUs it is often better to instrument a representative sample per floor or zone and use that to drive the change round, and we will tell you when that is the more sensible answer.
Does this replace our maintenance contract?
No. It changes what the visits are for. The contractor still attends, but goes to the units that are loaded with the right filters on the van, instead of walking an entire estate swapping everything on a date. Most FM providers are happy with that because it makes their visit productive.
Related solutions
Next step
Scope it with an engineer.
Tell us the site, the assets and the constraint. You get a bill of materials and a straight answer within one working day.
- A bill of materials sized to your site
- Priced ex VAT, UK entity, no login wall
Rather talk it through? Call 023 9223 3611
Received. An engineer has it.
You will hear back within one working day with the parts, the prices and the lead time. A confirmation is on its way to your inbox.
If it is urgent, call 023 9223 3611.