A 2015 Harvard T.H. Chan School of Public Health study tested cognitive performance across different CO2 concentration levels. At 550 ppm — typical outdoor air — performance was baseline. At 1,000 ppm — the EPA recommended maximum for indoor spaces — performance dropped 11% on decision-making tasks. At 2,500 ppm, it dropped 50%.
A full conference room running a two-hour strategy session in a poorly ventilated space can hit 2,000–2,500 ppm within 45 minutes. The executives in that room are making decisions at half their cognitive capacity, and nobody knows because no one is measuring the air.
Indoor air quality is one of the few building system parameters that directly affects human performance, not just comfort. And it is one of the least monitored, because the sensors were not standard equipment when most commercial buildings were constructed.
VX-Olympus deploys a wireless IAQ monitoring layer that makes air quality continuous, visible, and actionable.
What Indoor Air Quality Actually Measures
Carbon Dioxide (CO2)
CO2 is exhaled by every occupant in the space. In well-ventilated areas, the outdoor air dilutes CO2 concentration. In under-ventilated spaces or rooms with high occupancy, CO2 builds up.
CO2 readings indicate two things simultaneously:
- Ventilation effectiveness — is outdoor air turnover sufficient for the current occupancy load?
- Occupancy proxy — CO2 rises linearly with occupant count and time spent in a space. It is a passive occupancy indicator without any identity tracking.
Reference thresholds:
- 400–500 ppm: Outdoor baseline. Excellent ventilation.
- 800–1,000 ppm: ASHRAE 62.1 target for occupied spaces. Good.
- 1,000–1,500 ppm: Degraded ventilation. Occupants may begin to feel stuffiness.
- 1,500–2,500 ppm: Clearly poor ventilation. Cognitive performance affected.
- 2,500+ ppm: Requires immediate ventilation response.
Total Volatile Organic Compounds (TVOC)
VOCs are gases emitted by building materials, cleaning products, off-gassing from furniture and carpeting, and certain occupant activities. Common sources: formaldehyde from engineered wood products, benzene from some paints and adhesives, acetaldehyde from flooring adhesives.
Short-term exposure at elevated levels causes eye and throat irritation. Long-term exposure to certain VOCs is associated with more serious health effects. The IAQ concern in commercial buildings is typically low-level chronic exposure from off-gassing materials.
TVOC sensors measure total organic compound concentration. A spike in TVOC after a cleaning event, a renovation, or the installation of new furniture is normal and transient. A sustained TVOC elevation is a signal to investigate the source.
PM2.5 (Fine Particulate Matter)
Particles smaller than 2.5 micrometers penetrate deeply into the respiratory system. Sources in buildings: outdoor pollution infiltration, combustion from nearby sources, HVAC filter bypass, and indoor activities.
PM2.5 spikes correlate with HVAC filter condition — a filter approaching end-of-life allows progressively more particulate through. Monitoring PM2.5 provides an indirect indicator of HVAC filter performance.
Temperature and Relative Humidity
Temperature and humidity affect occupant comfort, productivity, and health. ASHRAE recommends 68–76°F with 30–60% relative humidity for office occupancy.
Humidity outside the 30–60% range creates problems:
- Below 30%: Dry air causes respiratory irritation, static electricity buildup, and increased survival time for airborne pathogens.
- Above 60%: Condensation on surfaces, accelerated mold growth, and occupant discomfort.
Temperature deviations outside the comfort range affect productivity in measurable ways. Monitoring confirms that HVAC setpoints are actually resulting in the intended conditions — not just that the thermostat is set to the right number.
From Measurement to Action
Measuring air quality is the first step. Responding to it is the second.
VX-Olympus rule chains link IAQ sensor readings to HVAC control commands:
CO2 threshold exceeded: When CO2 in a zone rises above 1,000 ppm and occupancy indicates the space is in use (not just an early-morning reading spike from the previous evening), VX-Olympus can command the HVAC controller to increase fresh air intake. When CO2 returns to the target range, the command reverts to normal ventilation mode.
Humidity excursion: Sustained humidity above 60% in a zone triggers investigation. Is the HVAC humidity control failing? Is there a moisture source (plumbing leak, exterior infiltration)?
TVOC spike: A TVOC reading that spikes significantly above baseline triggers an alert to facilities management. Not an automated HVAC response — a notification that a source investigation is warranted.
Temperature out of range: When a zone’s temperature deviates from setpoint by more than 3°F for more than 20 minutes during occupancy hours, alert the facilities team. This indicates either a thermostat failure, a zone control issue, or an HVAC unit problem.
Occupancy Tracking for Space Utilization
IAQ sensors with CO2 monitoring provide passive occupancy information. For more precise space utilization data, VX-Olympus integrates with dedicated occupancy sensors:
- Passive infrared (PIR) motion sensors — detect presence by motion. Binary (present/not present). Low cost, simple, misses occupants who are sitting still.
- People counting cameras (privacy-preserving, count-only) — count individuals entering and exiting spaces. Directional accuracy. Requires camera hardware.
- Under-desk presence sensors — ultrasonic or radar-based sensors under desks detect seated occupancy without motion. Used for desk utilization analysis in hybrid work environments.
- Wi-Fi/Bluetooth probe counting — passive detection of device signals. Estimate of occupant count from device density. Privacy-sensitive; used with disclosed policies.
Occupancy data in VX-Olympus drives several operational insights:
Space utilization analysis: How often is each conference room actually occupied versus booked? Which desk zones see consistent high utilization and which are consistently empty? For commercial real estate operators and enterprise tenants renegotiating leases, utilization data either confirms space adequacy or justifies footprint reduction.
Cleaning dispatch: After a meeting room has been occupied by N people for M minutes, dispatch a cleaning task rather than cleaning on a fixed schedule. Targets cleaning labor where it is actually needed.
HVAC optimization: Reduce HVAC energy in unoccupied zones during occupied hours — not just during off-hours. A suite that shows zero occupancy at 2 PM on a Friday can reduce its HVAC load without waiting for the end-of-day schedule.
Multi-Floor and Multi-Building View
For large buildings or multi-building campuses, VX-Olympus organizes IAQ data hierarchically:
- Campus map view: Each building as a block. Color indicates current aggregate IAQ status.
- Building floor plan view: Each zone or room on the floor plan. Click any room to see CO2, TVOC, temperature, humidity, and occupancy in real time.
- Alert dashboard: Active IAQ threshold breaches across all spaces, sortable by severity and time.
- Historical trend reports: Average CO2 by floor or zone for the week/month, TVOC events by frequency, occupancy utilization by room type.
Hardware and Deployment
IoT IAQ sensors are self-contained, battery-powered, and wireless. Common form factors:
- Wall-mounted units (similar to a smoke detector) for general zone monitoring
- Ceiling-mounted units for open-floor environments
- Small desktop units for individual offices or meeting rooms
Most deployments use LoRaWAN or Wi-Fi connectivity depending on the building infrastructure. LoRaWAN provides multi-year battery life and building-wide coverage from a single gateway. Wi-Fi provides higher data frequency for spaces where real-time response is critical.
Typical VX-Olympus IAQ deployment sequence:
- Assess zones to monitor — conference rooms, open offices, high-density areas
- Install sensors at 6–8 foot height in monitored zones (avoid placement near HVAC supply registers)
- Install LoRaWAN gateway if not already present (1 per floor in most commercial buildings)
- Register sensors in VX-Olympus, configure alert thresholds per zone
- Integrate with BAS if automated HVAC response is desired
Deployment time per floor: 2–4 hours for sensor placement and registration. BAS integration requires coordination with the building’s controls system vendor or an experienced controls integrator.
The Outcome
Air quality monitoring is inexpensive to deploy relative to the cost of the building it operates in. The ROI is measured in avoided health impacts, energy savings, competitive positioning for buildings that can demonstrate their air quality.
Talk to our team about an IAQ monitoring deployment scoped to your building size and existing HVAC control infrastructure.