Sensors are the senses of a building automation system — every control decision is only as good as the reading behind it. The common types are temperature, humidity, pressure (static and differential), carbon dioxide, and flow. What matters most for a Tampa Bay building is not the sensor brand but its accuracy, its placement, and whether it stays calibrated, because a drifted sensor quietly makes the whole system run wrong.
A building automation system reads conditions, decides, and acts. The reading comes first — and if it is wrong, the decision and the action are wrong too. A temperature sensor reading three degrees high will make a system overcool a space forever, and no amount of clever programming will fix a bad input.
This is why sensor selection, placement, and calibration are not details. They are the foundation the entire control sequence stands on.
Temperature is the most common measurement in a building — space temperature, supply and return air, chilled and hot water, and outdoor air. Most use thermistors or RTDs (resistance temperature detectors), which change electrical resistance with temperature.
Placement is everything: a space sensor in direct sun, above a heat source, or in dead air reads the wrong number. A supply-air sensor too close to a coil reads stratified air. Good design puts the sensor where it represents what the control is actually trying to manage.
In Florida, humidity sensors earn their keep. They measure relative humidity, and in critical applications dewpoint, so the system can control moisture rather than just temperature. They drive dehumidification, reheat, and ventilation decisions.
Humidity sensors drift more than temperature sensors and need periodic calibration. A humidity sensor reading low will let a building run damp — the exact failure a humid climate cannot afford. See DOAS and dehumidification.
Pressure sensors come in two roles. Static pressure sensors in ductwork tell a variable-air-volume system how hard the fan must work to deliver air. Differential pressure sensors measure the difference across a filter (to flag when it is dirty), across a coil, or between two spaces (to verify a pressure relationship).
Building pressure relationships — keeping a space positive or negative relative to its neighbors — depend entirely on accurate differential pressure sensing, which matters in kitchens, labs, and clinical spaces.
Carbon dioxide sensors estimate occupancy by measuring the CO2 people exhale, which drives demand-control ventilation — ventilating based on how full a room actually is. In a humid climate, not over-ventilating an empty room with hot, wet outdoor air is a direct energy saving.
CO2 sensors need calibration to stay accurate; a drifted CO2 sensor either over-ventilates (wasting energy) or under-ventilates (hurting air quality).
Flow sensors measure air or water movement — airflow stations in ducts, water-flow meters in hydronic loops. They confirm that equipment is actually delivering what the sequence commands, and they enable energy measurement and verification.
Flow measurement is harder than temperature, and accuracy depends on installation: enough straight pipe or duct before and after the sensor for the flow to be stable. Crowded installations read poorly.
Three things decide whether a sensor helps or hurts. Accuracy — the right grade for the job; a process needing tight control needs a tighter sensor. Placement — where it truly represents the controlled condition. Calibration — sensors drift over time, and a drifted sensor is worse than no sensor because it is confidently wrong.
A controls system should be commissioned with verified sensors and re-checked periodically. See trending and fault detection for how drift is caught.
The common measurements are temperature (space, supply/return air, water, outdoor), relative humidity and dewpoint, pressure (duct static pressure and differential pressure across filters, coils, or between spaces), carbon dioxide for occupancy-based ventilation, and air or water flow. Each feeds a control decision.
A sensor only helps if it represents the condition being controlled. A space temperature sensor in sunlight, above a heat source, or in dead air reads the wrong value, causing the system to control to a false number. Correct placement is as important as sensor accuracy.
Yes. Sensors drift over time — humidity and CO2 sensors especially. A drifted sensor is worse than none because the system confidently controls to a wrong reading. Sensors should be verified at commissioning and re-checked periodically; trending and fault detection help catch drift.
In a humid climate, controlling moisture matters as much as temperature. Humidity sensors drive dehumidification, reheat, and ventilation decisions. A humidity sensor reading low lets a building run damp — the failure a Florida building cannot afford — so accuracy and calibration are critical.
Suncoast Cold Systems installs, wires, and configures the HVAC controls integral to the mechanical systems we provide — and specifies open protocols (BACnet, Modbus, open supervisory platforms) so you own your building’s controls and data, with no proprietary dealer lock-in. Where a project calls for certified systems integration, we coordinate it within one accountable mechanical scope. Licensed Florida Class A Air Conditioning Contractor (FL #CAC1824642).
The devices that act on what sensors read.
How sensors and outputs are counted and specified.
Open-protocol controls, installed within our Class A scope.