HVAC&R solutions

HVAC&R monitoring and control, from the chiller plant to the cold room

HVAC&R monitoring and control covers heating, ventilation, air conditioning and refrigeration equipment, from chillers and air handlers to cold rooms and compressors. Aqueduct meters and senses that equipment, finds faults and early signs of failure, optimizes energy against a weather-normalized baseline, controls over BACnet and Modbus where control is enabled with owner approval, and keeps evidence for temperature-critical spaces.

Powered by aQ EnergySmart, aQ PredictIQ, aQ Assurance and Smart Controls, built on aQ Core
Large industrial fans on a plant wall
Pipework and valves in a plant room
Compressor 2 · condition
7.1 mm/s vibration
Maintenance scheduled before failure
Demo data

Every chiller, compressor and cold room measured, diagnosed and run to its load.

Plant efficiency

Chiller and refrigeration efficiency measured, not estimated

  • kW per ton

    Plant efficiency comes from electrical input against cooling output from BTU meters, per chiller where feeders allow.

  • Low delta T

    Chilled water temperature difference is trended against load, so the most common chronic fault shows as a trend.

  • Cooling energy ratio

    Refrigeration groups are compared on energy per unit of cooling under similar operating conditions.

Insulated pipes against the sky
Energy balance · active power
412Grid+146Solar=338HVAC+99Light+16Loss
Power factor 0.96Carbon today 1.9 t
Demo data
Early warning

Faults diagnosed and failures caught before the room warms

  • Command against feedback

    Failed starts, units left in manual and valves not following their command surface as a standing list.

  • Early signs of failure

    Compressor vibration, a new sound signature and energy drift schedule maintenance before the failure happens.

  • Routed to your CMMS

    Each finding goes to the responsible role and into your CMMS with the evidence and a recommended fix.

Air conditioning units on a building wall
Compressor 2 · condition
7.1 mm/s vibration
Maintenance scheduled before failure
Demo data
Control and evidence

Equipment controlled with approval, records kept for audits

  • BACnet and Modbus

    The field device network controller reaches chillers, AHUs, RTUs and VAV boxes where control is enabled.

  • Lockout protection

    Lockouts block new commands mid-action, protecting compressors and fans from short cycling and repeated starts.

  • Continuous evidence

    aQ Assurance keeps temperature and pressure records, deviations with closure and exports for any assessment period.

Corridor between stainless tanks
Command history · RTU-2
Occupied mode07:00 · executed
Economizer on07:12 · executed
Lockout active07:13 · held
Demo data
Old way vs the Aqueduct way

HVAC&R operations, before and after Aqueduct

The old way
  • Chiller efficiency is a nameplate figure, not a measurement.
  • Fouled condensers show up as a bigger electricity bill.
  • A unit left in manual is found by a complaint.
  • Compressors fail first, and the repair is the warning.
  • Cold room records are manual readings taken between checks.
The Aqueduct way
  • kW per ton is measured from electrical input and cooling.
  • Rising power at flat cooling flags poor heat removal early.
  • Units left in manual sit on a standing list.
  • Vibration and energy drift schedule maintenance before failure.
  • Cold room temperature is a continuous record with every excursion.
Coverage

HVAC&R equipment Aqueduct covers, and what is measured

Existing meters, BMS points and controllers are read where they exist. New sensors are installed through partners only where the site is blind.

EquipmentMetered and sensedWhat Aqueduct derives
Chillers and chilled water plantFeeder kW and kWh, BTU meter flow and header temperatures, run, trip and auto or manual statekW per ton, coefficient of performance, delta T, runtime balance
Cooling towersMake-up water flow, TDS and pH, condenser water temperaturesMake-up use and water quality trends, approach where wet bulb is measured
AHUs and RTUsSupply and return air temperature, return humidity, valve and damper position, fan status, filter alarmComponent states on the twin, command against feedback, setpoint attainment
VAV boxesZone temperature, damper position and setpoints over BACnet or ModbusComfort compliance and the zones driving each reset
Boilers and hot waterHeating status, hot water supply temperature, gas use in therms or cubic metersHot water reset opportunities and heating use against degree days
Refrigeration compressors and condensersDischarge pressure, temperatures, condenser water flow, matched electrical input, vibrationEnergy per unit of cooling, poor heat removal, early signs of failure
Cold roomsRoom temperature and humidityExcursions with time and duration, linked to the plant serving the room
Problem

Where HVAC&R goes wrong quietly

Most HVAC&R faults do not stop the plant. They make it work harder until something trips or a room drifts.

01

Low delta T

The most common chronic chilled water fault. Pumps move more water for the same cooling and the plant loses efficiency.

02

Poor heat removal

Fouled condensers or low condenser water flow push discharge pressure up, and compressors burn more power for the same cooling.

03

Plant left in manual

A unit left in hand after maintenance, or commanded on and not running, is noticed only when an area complains.

04

Excursions between checks

A cold room or critical space drifts between manual readings, and the record shows a log entry instead of what happened.

Faults and early signs

What Aqueduct finds in HVAC&R equipment

Faults found, diagnosed and routed. Early signs of failure caught before the fault.

Failed starts and uncommanded running

Start command against run status on chillers, pumps, air handlers and fans, with the time and duration.

Valves and dampers not following

Command against feedback finds a stuck, hunting or disconnected actuator before the area it serves overheats.

Setpoint deviation

A sustained gap between what a unit is asked to do and what it achieves, on air and chilled water.

Trip frequency

Repeated trips on one item flagged ahead of a failure, not after it.

Filter alarms left standing

Dirty filter alarms tracked with how long each has stood, so changes follow condition, not the calendar.

Vibration and sound signatures

aQ PredictIQ reads compressor vibration, a new sound signature and energy drift, and schedules maintenance before failure.

Plant equipment in an industrial hall
What we believe

Cold chain reliability starts with every compressor and cold room measured continuously.

Talk to our team
How it works

How HVAC&R control works in Aqueduct

Two routes to equipment, both used only where control is enabled with owner approval.

01

Field device network controller

Chillers, AHUs, RTUs and VAV boxes connect over BACnet IP, Modbus TCP or serial. The controller translates to MQTT for Aqueduct.

02

LoRaWAN relays

Simple loads such as exhaust fans, ventilation fans and lighting switch through LoRaWAN relay switches.

03

Desired and reported state

Each field device holds a desired and a reported state, so Aqueduct knows whether equipment did what it was told.

04

Lockouts and command history

Lockouts block new commands mid-action to prevent short cycling. Command history records whether every command executed.

05

Read-only where required

Hospitals and other critical sites can run read-only, with an outbound data path and nothing written to existing controls.

Problem, solution, impact

Problem, solution, impact

Where HVAC&R monitoring and control pays back.

The problemHow Aqueduct solves itThe impact
Energy

Compressors working against fouled condensers.

Power and pressure trended against cooling output under similar conditions.

Chiller kW per ton tracked against its own baseline, with each saving verified at the meter.

Water

Cooling towers fed make-up water nobody measures.

Make-up flow, TDS and pH tracked hour by hour.

Tower water use made visible, with blowdown and drift losses named and priced.

Operations

Faults found when a room gets warm.

Command against feedback rules route each fault to the responsible role.

Repairs routed to your CMMS and confirmed at the meter.

Related

Evidence for temperature-critical spaces

aQ Assurance organizes measurements into a continuous record. Your team or your consultant files and certifies.

Cold room temperature recordOperating room pressureIsolation room pressureSterile services conditionsDeviation history with closureEvidence export for any periodGenerator run records
By application

HVAC&R across the sites Aqueduct runs in

The equipment is similar everywhere. What matters, and what the record must show, differs by application.

01 / 05

Cold rooms and refrigeration plant

Product safety depends on room temperature, and electricity depends on the compressors and condensers keeping it there. Both drift slowly.

  • Room temperature and humidity with excursion duration
  • Energy per unit of cooling per refrigeration group
  • Compressor vibration and sound signature
Measured
room conditions, discharge pressure, kW
Risk
excursions and compressor failure
Aqueduct
aQ Assurance record and aQ PredictIQ warnings
02 / 05

Clinical air systems

Operating and isolation rooms are held to temperature, humidity and pressure bands. Many hospitals run Aqueduct read-only alongside the existing BMS.

  • Limits per room class
  • Pressure cascades per suite
  • Plant mapped to the rooms it serves
Measured
temperature, RH, differential pressure
Risk
excursions between rounds
Aqueduct
continuous record, read-only where required
03 / 05

Commercial HVAC

Waste comes from schedules, overrides and stuck components that keep comfort just acceptable.

  • RTU and AHU component states
  • Occupancy-driven rules where enabled
  • Comfort compliance per zone
Measured
unit states, zone temperature, CO2
Risk
energy waste and complaints
Aqueduct
Smart Controls with command history
04 / 05

Critical cooling

Cooling availability comes first, efficiency second. Command against feedback and early warnings matter more than setbacks.

  • Chiller and CRAH status against command
  • Trip frequency
  • Cooling energy against IT load
Measured
plant status and power
Risk
loss of cooling
Aqueduct
early warning and diagnosis
05 / 05

Gulf and tropical sites

Cooling is the dominant electrical load, and condensers degrade faster in dust and heat.

  • kW per ton against wet bulb where measured
  • Condenser performance trends
  • District cooling consumption where supplied
Measured
plant efficiency and load
Risk
efficiency loss under peak heat
Aqueduct
plant efficiency against baseline
By the numbers

Why HVAC&R gets close attention

80%

up to this share of a UAE building's electricity demand goes to cooling

Source: Heriot-Watt University: Retrofit options to reduce climate change impacts on UAE buildings
20 to 60%

ASHRAE 170 design relative humidity range for operating rooms

Source: ASHRAE Journal: Conditioning for the environment of critical care hospital operating rooms
How it rolls out

From read-only monitoring to control

Most sites start read-only. Control is added where it is enabled, with owner approval, once the data has earned trust.

1
Weeks 1 to 2

Connect the plant

Chiller plant managers, BMS points and power meters connect over BACnet or Modbus through a field device network controller, read-only.

2
Weeks 2 to 4

Fill the blind spots

BTU meters, cold room sensors and vibration sensors are installed through partners only where the site has no data.

3
Weeks 4 to 8

Baseline and diagnose

Plant efficiency and asset baselines are learned. Faults and early warnings route into your CMMS.

4
Month 3 onward

Control where approved

Schedules, staging and setpoints are enabled unit by unit, with owner approval, lockouts and command history.

Plant KPIs

HVAC&R KPIs and what drift usually means

The KPIs to trend for each part of the plant, and the cause engineers check first when one moves.

KPIEquipmentDrift usually means
kW per tonChillersFouled condenser, poor staging or low delta T
Delta T against loadChilled water loopCoil valves open too far or bypass flow
Energy per unit of coolingRefrigeration groupsPoor heat removal or refrigerant issue
Discharge pressureCompressors and condensersCondenser fouling or low condenser water flow
Make-up flow and conductivityCooling towersBlowdown set wrong or a stuck float valve
Excursion minutesCold roomsDoor practice, defrost timing or plant capacity
Setpoint attainmentAHUs and RTUsStuck damper, valve or undersized capacity
The refrigeration circuit

A refrigeration plant, point by point

Refrigeration faults rarely stop the plant. They raise lift, lengthen run times and warm the room slowly. These are the points where that starts, and what Aqueduct reads, from the rack controller over BACnet or Modbus or from added sensors where the site is blind.

Compressor rack

Where it goes wrong

Too many compressors staged for the load, or one compressor short cycling while others idle.

What we measure

Compressor status and stage, rack kW, starts per hour, vibration where fitted

What Aqueduct does

Energy per unit of cooling per rack, short cycling and early signs of failure through aQ PredictIQ

Suction pressure

Where it goes wrong

Suction held lower than the warmest case or room needs, raising lift on every compressor.

What we measure

Suction pressure and saturated suction temperature

What Aqueduct does

Shows headroom between suction temperature and what the loads actually require

Discharge pressure

Where it goes wrong

High head pressure from a fouled condenser, failed fan or a fixed head pressure setpoint in cool weather.

What we measure

Discharge pressure, condensing temperature, ambient temperature

What Aqueduct does

Flags rising discharge pressure at similar load and ambient as poor heat removal

Condensers

Where it goes wrong

Dirty coils, failed fans or low condenser water flow; heat removal slowly falls.

What we measure

Condenser fan status, condenser water flow and temperatures where water cooled

What Aqueduct does

Condenser approach trended, cleaning recommended from the trend, not the calendar

Evaporators

Where it goes wrong

Iced coils, failed fans or poor superheat control cut capacity and stretch run times.

What we measure

Coil and air temperatures, evaporator fan status, superheat where available

What Aqueduct does

Room temperature recovery and run time per evaporator against its own history

Defrost

Where it goes wrong

Defrost too often wastes heat and energy; too rarely and the coil ices.

What we measure

Defrost start and end, termination temperature, room temperature during and after

What Aqueduct does

Defrost duration and room recovery per cycle, with excursions tied to the cycle

Doors

Where it goes wrong

Doors held open during loading let in heat and moisture, which becomes ice on the coil.

What we measure

Door open events and duration where door contacts are fitted

What Aqueduct does

Door open minutes laid over room temperature and defrost demand

Cold room

Where it goes wrong

Product temperature at risk between manual checks.

What we measure

Room temperature and humidity, continuously

What Aqueduct does

Excursions with time and duration, kept as a record by aQ Assurance

Cold rooms

What a cold room record should explain

A cold room temperature trace is the result of the plant, the doors, the defrost and the product all at once. Reading them together turns an excursion into a cause.

01 / 05

Pull-down after loading

Warm product and an open door lift the room temperature. How fast the room recovers says whether the plant has capacity left.

  • Recovery time after each loading event
  • Recovery compared with the same room in previous weeks
  • Slower recovery flagged before an excursion happens
Measured
room temperature, door events, rack kW
Signal
recovery time lengthening
Aqueduct
links slow recovery to the rack serving the room
02 / 05

Defrost cycles

Every defrost adds heat that the plant then removes. Room temperature during and after each defrost shows whether the schedule fits the frost load the room actually sees.

  • Defrost duration and termination
  • Room temperature peak during defrost
  • Defrost frequency against door open time
Measured
defrost status, coil and room temperature
Signal
long defrosts or excursions tied to defrost
Aqueduct
shows each defrost against the room record
03 / 05

Door practice

Door open time drives moisture into the room, which ices the coil and forces more defrost. It is often the cheapest fix on the site.

  • Door open minutes per shift
  • Long openings flagged with time of day
  • Door time compared with room excursions
Measured
door contact events
Signal
open minutes rising
Aqueduct
sends findings to the shift lead with the trace
04 / 05

Humidity and ice

High room humidity in a freezer or chiller usually means moisture is entering faster than the coil can manage it, through doors, seals or wash down.

  • Room humidity alongside temperature
  • Ice build up inferred from coil temperature and fan run
  • Seal and curtain inspections prompted by trend
Measured
room relative humidity
Signal
humidity high outside wash down
Aqueduct
routes the finding to maintenance
05 / 05

The temperature record

Continuous readings replace manual log entries. Each excursion carries its start, its duration, its peak and its closure.

  • Excursion minutes per room
  • Deviation with cause and closure
  • Export for any assessment period
Measured
temperature and humidity per room
Evidence
continuous record with deviations
Aqueduct
aQ Assurance keeps it; your quality team or auditor reviews it
How it works

Chillers, AHUs and zones as one connected plant

01

The zone asks

VAV boxes and zone sensors report temperature, damper position and cooling demand. This is the real load, and it is where every reset should start.

02

The AHU answers

Supply air temperature, static pressure and chilled water valve position show how hard each air handler works to satisfy its zones. A coil at a fully open valve is the constraint on the chilled water loop.

03

The loop carries it

Chilled water flow, delta T and loop differential pressure show whether the coils are using water well. Low delta T at the plant is usually caused out at the coils.

04

The chillers produce it

Chiller kW, cooling in tons and condenser conditions give kW per ton. Staging decisions depend on both the load and the delta T the coils return.

05

The towers reject it

Condenser water temperatures, tower fan power and wet bulb give tower approach. Because Aqueduct holds all five levels on one data layer, a symptom at one level is traced to its cause at another.

Fault signatures

HVAC&R fault signatures, and what to do about each

Each fault leaves a pattern in the data before it leaves a warm room. These are the ones plant engineers ask about most.

SymptomLikely causeData that shows itAction
Discharge pressure rising at the same load and ambientFouled condenser, failed condenser fan, low condenser water flowDischarge pressure, condenser fan status, rack kW against coolingClean the condenser, check fans and flow, confirm pressure falls
Compressors short cyclingLoad far below the smallest stage, narrow pressure band, low chargeStarts per hour, on and off durations, suction pressureWiden the control band, review staging, check charge
Room recovers more slowly after each loadingIced evaporator, failed evaporator fan, plant near capacityRecovery time, coil temperature, fan statusCheck defrost and fans before adding capacity
Excursions during defrostDefrost too long, termination set wrong, heaters stuck onDefrost duration, termination temperature, room peakAdjust termination and schedule, inspect heaters
High room humidity and frequent defrostDoors held open, damaged seals or curtainsDoor open minutes, humidity, defrost countAddress door practice, repair seals
Chiller kW per ton drifting upCondenser tube fouling, poor staging, low delta TkW per ton by load band, condenser approach, delta TClean tubes, review staging, chase the low delta T
Low chilled water delta TCoil valves not closing, fouled coils, low AHU setpointsDelta T against load, valve positions, decoupler flowRepair valves, reset AHU setpoints, clean coils
Tower approach wideningFouled fill, poor water distribution, fan faultLeaving tower water temperature, wet bulb, fan kWInspect fill and nozzles, check fan and drive
Supply air temperature not met with valve fully openFouled or air bound coil, chilled water too warmValve position, supply air temperature, coil water temperaturesClean or vent the coil, check chilled water supply
Derived metrics

Refrigeration metrics worth trending

Energy per unit of cooling

Rack kW against the cooling delivered, compared under similar ambient and load, so heat removal problems show before a trip.

Lift

The gap between condensing and saturated suction temperature. Every unnecessary degree of lift is compressor energy the room did not need.

Starts per hour

Compressor starts counted per hour. Short cycling wears contactors and motors long before it shows on the bill.

Excursion minutes

Minutes outside the room limit, per room and per period, the number quality teams ask for first.

Defrost recovery

Minutes from defrost end to room temperature back in band, tracked per evaporator.

Door open minutes

Time doors stand open per shift, set against room humidity and defrost demand.

Trusted at scale
Read the case studies
Deployed275+

sites in 21 countries run on Aqueduct.

Healthcare22 hospitals

and 9 clinics in one of India’s top hospital chains.

AirportsTop 25

US airport running water intelligence on Aqueduct.

Real estate20M+ sq ft

of commercial real estate under Aqueduct.

Manufacturing300 acres

FMCG manufacturing campus.

Food and dairyMajor dairy

operations run on Aqueduct.

Questions

Common questions

HVAC&R monitoring and control means measuring heating, ventilation, air conditioning and refrigeration equipment continuously, finding faults and waste, and adjusting operation. Aqueduct covers chillers, cooling towers, AHUs, RTUs, VAV boxes, boilers, cold rooms and refrigeration compressors, and controls equipment where control is enabled with owner approval.

Measure pressure, temperature, condenser water flow and the electrical input of each compressor group, then compare energy against cooling output under similar conditions. Aqueduct flags rising energy with flat cooling as poor heat removal and recommends condenser and cooling tower checks before compressors fail.

Yes. Aqueduct tracks cold room temperature and humidity continuously, records each excursion with its time and duration, and links it to the refrigeration plant serving the room. Major dairy operations run on Aqueduct.

Through a field device network controller that speaks BACnet or Modbus to the equipment, and LoRaWAN relays for simple loads. Control runs only where it is enabled with owner approval, with lockouts against short cycling and a command history for every change.

Predictive maintenance looks for early signs of failure before a fault happens, such as rising compressor vibration, a new sound signature or energy drift. In Aqueduct, aQ PredictIQ reads these signals and schedules maintenance first, routing the work into your CMMS.

No. Aqueduct supplies the measured evidence: a continuous temperature record, deviations with their closure, and exports for any assessment period through aQ Assurance. Your team or your consultant files and certifies.

Yes. Aqueduct can read beside an existing BMS and plant manager without writing anything, take over control where the owner chooses, or be built into new construction. Its recommendations can be carried out through the systems you already run.

Yes. A hospital chain with 22 hospitals and 9 clinics is an Aqueduct client. In hospitals, Aqueduct tracks chiller plant efficiency, air handler states and critical room pressure, and can run read-only so existing validated control strategies stay as they are.

Yes, where the supply is metered with BTU or energy meters. Consumption is baselined against weather like any other utility.

Discharge pressure and compressor power rise for the same cooling output under similar conditions. That trend is flagged before efficiency loss turns into a trip.

Yes. Read-only deployments use an outbound data path and write nothing to existing controls. Control can be enabled later, with owner approval, if the hospital chooses.

A continuous temperature and humidity record per room, every excursion with its time and duration, and its closure. Your team or auditor uses the export; Aqueduct does not certify the room.

For cooling-heavy sites, kW per ton or energy per unit of cooling, because it shows efficiency loss as it develops. For cold storage, excursion minutes per room come first.

Floating head pressure lets condensing pressure fall with cooler ambient conditions instead of holding a fixed setpoint, which reduces compressor lift. Aqueduct shows discharge pressure against ambient so the opportunity is visible, and a change can be made through the rack controller or, where control is enabled, with owner approval.

No. Room temperature and humidity are the core record. Door contacts add the cause behind many excursions and are installed through partners where the site wants that detail.

Each excursion is set against the defrost status, door events and rack data for the same period. An excursion that starts and ends with a defrost reads very differently from one where the rack lost capacity.

Where the controller exposes data over BACnet or Modbus, the field device network controller reads it. Where it does not, pressure, temperature and power sensors are added through partners.

Because many plant faults are caused somewhere else. Low delta T at the chillers is usually caused at the coils, and a coil that cannot hold supply air is often a chilled water problem. One data layer lets the trace follow the cause.

See Aqueduct on your own facility.

Bring a site, a utility bill or a question. We will show you where the loss is.