AccQ Series · End-to-end certified
Certified measurement at the chiller plant and the AHU
The AccQ unit sits at two places on a typical HVAC plant: the chiller plant, and the air handler. Certified ΔT and power at those points make efficiency measurable, verification defensible, and a second loop possible without replacing the BMS.
Hardware detail lives on the AccQ page .
How to deploy AccQ for HVAC measurement?
Two AccQs, one at the chiller plant and one at the AHU.
Chiller plant
Chiller plant
Chiller plant zoom slot. Spec: design/specs/hvac-chiller-plant.md
/design/svg/hvac-chiller-plant.svg
AccQ is capable of measuring parameters across chillers, headers, and cooling towers
Measure
High-accuracy, high-resolution matched-pair chilled/condenser water supply/return delta-T and flow rate. Connect to your existing Modbus power meters for more.
Verify
Calculate plant efficiency in kW/ton. Diagnose low-deltaT syndrome on the chilled water loops, to inform needs for retrofit M&V and environmental sustainability audits.
Optimise
Use our optimisers, or external ones, to adjust pumps, chiller, and tower against those measurements. The BMS still starts equipment and keeps the sequence of operations.
AHU
AHU
AHU zoom slot. Spec: design/specs/hvac-ahu.md
/design/svg/hvac-ahu.svg
Monitor both water-side and air-side of your air handling units with one AccQ.
Measure
Start by monitoring cooling coil water ΔT (CHW supply/return at the AHU) and AHU electrical power. On the air side: supply vs return ΔT, and outdoor vs return air for economiser changeover.
Verify
Sensor error on the AHU is how buildings simultaneous-heat-and-cool. Certified coil and air ΔT make that visible. Economiser changeover mistimed on untrusted outdoor vs return air is lost free-cooling hours. Water ΔT and air ΔT on the same coil should agree; if they do not, the coil is not doing what the plant thinks.
Optimise
Economiser changeover on trusted outdoor vs return air. Fan trim on the second loop: the BMS still sends fan-start over Modbus TCP; AccQ executes and confirms; the control plane trims speed. Coil valve and leaving-air setpoint can trim on the same loop.
±0.02 °C*
Matched-pair ΔT tracking with calibrated thermistor pairs, CHW and CDW bands.
24 channels
Up to 24 channels of high-resolution water-temperature, 6 per module (12 matched ΔT pairs).
Auto re-calibration
AccQ recalibrates itself for each measurement cycle to ensure maximum accuracy.
*Anticipated accuracy, subject to final laboratory report.
Ready to better measure your HVAC plant?
Download the full AccQ Series specification, or talk to us about a pilot alongside your existing BMS.