An air handling unit spends most of its life needing far less air than it was sized for. A proper AHU control panel with VFD drives holds the duct pressure or the room condition you actually asked for, and lets the fan slow down the rest of the time — which is where almost all the energy saving in an HVAC system hides.
An AHU control panel — air handling unit panel — runs the fan, the dampers, the chilled or hot water valve and the safety interlocks for an air handling unit. On paper that sounds like a starter with a few contactors. In practice, the difference between a cheap AHU panel and a properly engineered one shows up on the electricity bill every month for the next fifteen years.
Here is why. Fan power follows roughly the cube of fan speed. Slow a fan to 80% and it draws close to half the power. Almost every AHU is sized for a peak condition that occurs on a handful of days a year, and then runs at that same peak speed all the time because a direct-on-line starter has no other setting. A VFD-driven AHU panel closing the loop on duct static pressure or return air temperature simply lets the fan slow down whenever the building is not asking for full air.
The panel is not the expensive part of an AHU. It is the part that decides what the expensive parts cost you to run — which is a strange thing to save money on.
Pharmaceutical clean rooms and HVAC plant rooms, hospitals and laboratories, food and beverage processing, commercial buildings, hotels and malls, IT and data centre precision cooling, textile and paint shop ventilation, and institutional buildings. We have built AHU panels with YASKAWA VFD drives for institutional HVAC projects including work delivered to IIT Jodhpur — multiple panels, GA drawings approved before manufacturing, and the control schematic supplied with the panel.
An AHU rarely sits alone. The same plant room usually needs a VFD pump control panel for the chilled water pumps, an APFC panel to fix the power factor that all those motors ruin, an MCC panel for the plant room as a whole, and a fire fighting panel whose trip signal the AHU must obey. Built together, they share one drawing set and one wiring standard.
Every AHU panel is designed, wired, ferruled and load tested in our own Faridabad workshop, and supplied with the GA drawing and control schematic your consultant will ask for.
Drive parameters set for the fan and the loop tuned on site. A VFD at default settings hunts, trips and wastes the saving you bought it for.
Duct static pressure, return air temperature or room condition — whichever your design actually calls for, with the sensor scaled correctly.
Filters changed when they are actually blocked, not on a calendar nobody follows. A blocked filter costs more in fan power than the filter costs.
If the drive fails, the fan still runs direct-on-line. A hospital does not stop ventilating while a spare is arranged.
Hard-wired fire trip input from the fire alarm panel, plus airflow proving and low-limit protection.
Modbus RTU or TCP and BACnet where specified, with the point list agreed at drawing stage rather than argued at commissioning.
Photographs from our Faridabad workshop and from customer installations.
ahu-control-panel.jpgComplete AHU panel, frontahu-panel-internal.jpgInternal wiring and ferrulingahu-panel-vfd.jpgVFD drive mountedahu-panel-hmi.jpgHMI setpoint screenahu-panel-ga-drawing.jpgGA drawing suppliedahu-panel-installed.jpgPanel installed in plant roomHVAC panels are usually built to a consultant specification, so we work from the schedule and the schematic and confirm every point in writing.
| Parameter | What it covers | Fixed at |
|---|---|---|
| Fan motor rating | kW, voltage and starting method for each fan | Enquiry |
| Control strategy | Constant volume, VAV, DP control or temperature control | Enquiry |
| VFD selection | Make and rating, with bypass arrangement if required | Drawing approval |
| Sensors | Temperature, humidity, duct DP, filter DP — type and range | Drawing approval |
| Dampers and valves | Actuator type, modulating or two-position, fail position | Drawing approval |
| Interlocks | Fire trip, airflow proving, low limit, door interlock | GA approval |
| BMS protocol | Modbus RTU or TCP, BACnet, and the agreed point list | GA approval |
| Enclosure | IP rating, material, mounting and cable entry | GA approval |
| Documentation | GA drawing, control schematic, cable schedule, test report | Always |
On HVAC projects the panel usually has to satisfy a consultant, a contractor and a facilities team who will inherit it. So we issue the GA drawing and control schematic first, get them approved, and build to the approved set — which is what stops the argument at handover about whether the fire trip was supposed to be hard-wired or through the BMS.
Every panel leaves with the approved drawings, the cable schedule, the VFD parameter list and a load test report. The facilities engineer who opens it in five years gets a panel that matches its drawing.
If the load varies at all, yes. Fan power follows roughly the cube of speed, so running at 80% speed uses close to half the power. Most AHUs are sized for a peak that happens on a few days a year and then run at that speed permanently. The drive pays for itself out of that gap.
Duct static pressure where you have VAV boxes downstream and the system must respond to their demand. Return air or room temperature where the AHU serves a fixed space. Your design decides it, and we wire and scale the sensor to match.
With a bypass arrangement the fan runs direct-on-line while the drive is repaired or replaced. For hospitals, clean rooms and process ventilation we recommend it as standard rather than as an option.
Yes — Modbus RTU or TCP, and BACnet where the specification calls for it. We agree the point list at drawing approval stage so commissioning is a connection rather than a negotiation.
Yes, before manufacturing. Approval of the drawing is what we build to, and the approved set is handed over with the panel along with the cable schedule and test report.
Yes. We have supplied multi-panel institutional HVAC projects with common wiring standards and a single drawing set, including work delivered to IIT Jodhpur with YASKAWA drives.
Yes — Delhi NCR, Gurugram, Manesar, Bhiwadi, Ghaziabad, Noida and across India.
Share the drawing or a photo on WhatsApp and we will come back with a method, a cycle time and a price.