CO₂ Monitoring Instruments

In the Harvard COGfx study (Allen et al., 2016), cognitive scores were about 15% lower at roughly 945 ppm, and about 50% lower at roughly 1,400 ppm, than at about 550 ppm. IAQ Detectors manufactures wall-mount and duct-type CO₂ transmitters with Modbus RS485 and Wi-Fi, purpose-built for HVAC systems, commercial buildings, schools, and demand-controlled ventilation.

CO₂ sensing Modbus RS485 Wi-Fi CE certified PAS technology

Browse all CO₂ products →Talk to an engineer

CO₂ level reference (ppm)

420 800 1,100 5,000

Outdoor air ~420 ppm

Well-ventilated target (WELL v2)<800 ppm

Common DCV setpoint 1,000 ppm

ASHRAE 62.1-2022 rate indicator (outdoor + 700) ~1,100 ppm

Health risk zone 5000+ ppm

ASHRAE 62.1-2022 sets ventilation rates, not a CO₂ limit. A steady-state level about 700 ppm above outdoor air (roughly 1,100 ppm) is the common indicator that the 62.1 rate is being met.

Product comparison

Wall mount vs duct type: quick specification reference

Feature	CO₂ Transmitter	Duct CO₂ Transmitter	CO₂ + T/RH Monitor	CO₂ Controller	6-in-1 IAQ Monitor
Mount type	Wall	Duct / In-line	Wall	Wall	Wall
CO₂ sensing	✓	✓	✓	✓	✓
Temperature	—	—	✓	—	✓
Humidity (RH)	—	—	✓	—	✓
VOC / PM sensing	—	—	—	—	✓
Relay output	✓ Optional	—	—	✓	—
Modbus RS485	✓	✓	✓	✓	✓
Wi-Fi	✓	—	—	—	✓
Display	✓	✓	✓	✓	✓
Best for	Offices, schools	AHU, HVAC ducts	Comfort + CO₂	Ventilation control	Complete IAQ

Common applications

Where CO₂ monitoring is critical

🏢

Commercial buildings

Monitor CO₂ in open-plan offices and meeting rooms for occupant productivity and to confirm ASHRAE 62.1-2022 ventilation rates are being met.

🏫

Schools & classrooms

High CO₂ levels reduce student focus. Wall-mount transmitters enable automatic ventilation triggers.

🏥

Hospitals & clinics

Infection control and ventilation adequacy validated through continuous CO₂ monitoring in wards.

🌬️

HVAC / AHU systems

Duct-type transmitters feed CO₂ data to building management systems for demand-controlled ventilation.

🏨

Hotels & hospitality

Ensure guest room air quality without energy waste. Occupancy-based ventilation via CO₂ setpoints.

🏭

Industrial environments

Safety monitoring in enclosed production areas, cold storage, and server rooms requiring ventilation control.

Expert guidance

Not sure which CO₂ transmitter fits your installation?

Our application engineers will recommend the right product based on your duct dimensions, building type, BMS integration, and compliance requirements. Most enquiries answered within 24 hours.

Talk to an expert →sales@iaqdetectors.com

+91 8121025651 · Hyderabad, India