Quick orientation
Use this page to assign each sensor a question, location, range, accuracy, maintenance and redundancy role.
Simple explanation
Sensor Architecture helps the grower assign each sensor a question, location, range, accuracy, maintenance and redundancy role. The crop requirement is the starting question, not an equipment size.
Biological purpose
Engineering begins only after the crop stage, biological load and acceptable room response are declared.
Operator explanation
Observe the crop, room pattern and change history before changing a control. Record what changed, where, when and under which operating mode.
Engineering explanation
Define the control volume, design case, load components, equipment boundaries, instrumentation and expected response. Biological requirement is not equipment size.
What to observe
Look for spatial gradients, time trends, surface condition, crop response, door events, water events, equipment state and alarms rather than a single display value.
What to measure
Retain sensor ID, unit, location, height or depth, timestamp, calibration state, crop stage, room load and operating mode with every measurement.
Variables that interact
assign each sensor a question, location, range, accuracy, maintenance and redundancy role. Temperature, moisture, carbon dioxide, air movement, crop load and control actions can move together, oppose one another or hide a local problem.
What can go wrong
Common errors include a non-representative sensor, an undefined design case, a fan rating treated as delivered airflow, an air-change rate treated as distribution, or a biological target treated as plant capacity.
What changes at commercial scale
Larger crop loads, longer air paths, more simultaneous equipment, tighter recovery needs and higher failure consequences increase the need for redundancy, commissioning and data history.
Reference and review boundary
Background/reference map: AMCA Publication 201-23: Fans and Systems; Improving Fan System Performance: A Sourcebook for Industry; ISHRAE standards and position papers; ASHRAE Handbook Fundamentals, Chapter 1: Psychrometrics. This map supports further editorial work; it is not route-specific technical validation. Foundational, current, regulatory and engineering references retain their distinct roles, and manufacturer literature may only establish equipment-specific data.
Sensor architecture library
A sensor is a measurement system with a location, purpose, verification method and failure history.
SENSOR-AIR-TEMP-RHAir dry bulb and relative humidity
Does the point represent crop air rather than a wall, coil discharge or door plume?
- Installation
- Shield from radiant and wetting bias; Record height, rack, aisle and air path; Allow service access
- Verification
- Compare against a traceable reference; Verify time alignment and logging interval; Inspect drift after wet cleaning
- Failure modes
- Condensation on element; wall temperature bias; unrecorded replacement
SENSOR-COMPOST-TEMPCompost temperature
Are depth, bed position, rack level and insertion contact repeatable?
- Installation
- Define insertion depth; Map representative beds; Protect cable and connector
- Verification
- Cross-check probes; Record point identity; Review response time
- Failure modes
- shallow insertion; poor contact; single-point overconfidence
SENSOR-CO2Carbon-dioxide concentration
Can the placement reveal gradients rather than only return-air average?
- Installation
- Record height and air path; Avoid direct fresh-air jet; Provide calibration access
- Verification
- Zero/span method per instrument; Compare map points; Review pressure and cross-sensitivity limits
- Failure modes
- drift; condensation; blocked sample line; false representativeness
SENSOR-PRESSUREDifferential pressure
Are the reference zones, tube routes and door states defined?
- Installation
- Label high and low ports; Protect tubes from water; Locate reference away from local jets
- Verification
- Zero check; leak check; door-state test
- Failure modes
- reversed tubes; water in line; undefined reference
SENSOR-AIR-VELOCITYAir speed and direction
Is the instrument suitable for low-speed, directional mapping among racks?
- Installation
- Define orientation; use repeatable grid; record occupied crop state
- Verification
- instrument zero and calibration; repeat traverse; compare supply and return balance
- Failure modes
- orientation error; operator blockage; snapshot treated as permanent
Technical diagrams
Original diagrams expose system boundaries, air paths, feedback and engineering handoffs.
Printable field sheets
Download a blank CSV, open it in a spreadsheet, and record the actual observations with units and references. These educational templates are not acceptance criteria or engineering certificates.
Evidence and review
Source type, applicability and limitations stay visible so older farm guidance is not mistaken for current engineering law.
current · airflowAMCA Publication 201-23: Fans and Systems
Fan ratings, installed-system effects and the relationship between fan and system curves.
The standard does not supply a mushroom-room duty point or distribution result.
Open primary sourcefoundational · airflowImproving Fan System Performance: A Sourcebook for Industry
System curves, fan components, resistance, control and performance verification.
General fan engineering requires project measurements and a qualified designer for final selection.
Open primary sourcecurrent · hvacISHRAE standards and position papers
Indian HVAC standards context including air-handling units and commissioning.
Standard titles are an index; design claims must cite and comply with the applicable edition and project jurisdiction.
Open primary sourcefoundational · psychrometricsASHRAE Handbook Fundamentals, Chapter 1: Psychrometrics
Moist-air properties, psychrometric relationships, measurement and process calculations in SI units.
Equations describe air properties; they do not determine a crop target or equipment selection by themselves.
Open primary source