Carbon Dioxide Module for HVAC Applications



  • Compact, OEM module for demand-controlled ventilation and other CO2 measurement applications
  • Incorporates Vaisala CARBOCAP®, the silicon based NDIR sensor with unique internal referencing
  • Advanced, single-beam, dual wavelength measurement with no moving parts
  • Excellent long-term stability
  • Ideal for ventilation control in all types of occupied spaces


Most of us spend 90% of our time indoors. Consequently, good indoor air quality is important to our wellbeing. All human beings produce carbon dioxide gas by respiration, thus the carbon dioxide level can be used as an indicator for indoor human presence. A high CO2 level is a sign of poor ventilation and often an indication of other unpleasant odors in the air. In many buildings the ventilation need varies throughout the day. Demand controlled ventilation is an economical way to ensure good air quality.

The Vaisala CARBOCAP® CO2 sensors have been proven to be accurate and durable. They have an excellent long-term stability, which decreases maintenance. The superior performance of Vaisala CARBOCAP® sensors results largely from the stable reference provided by the electrically tunable Fabry-Perot Interferometer (FPI).

The tunable FPI filter measures CO2 absorption, and simultaneously a reference wavelength. This internal reference measurement compensates effectively for any changes in the optical path, such as light source intensity changes and contamination. In the HVAC market, this type of reference measurement is a unique feature to Vaisala CARBOCAP® products, distinguishing them from competitors’ comparative products that do not have a reference measurement at all, or have an indirect reference measurement, which is based on an assumed background CO2 levels. In buildings with around-the-clock occupancy (e.g. hospitals, work-places, residential buildings, retirement homes), the assumed background CO2 level reference is simply not applicable. The true internal reference measurement of Vaisala CARBOCAP® CO2 transmitters provides years of stable CO2 measurements.

The GMM112 Carbon Dioxide Module is designed especially for DCV (Demand Controlled Ventilation) applications with three optional CO2 measurement ranges of 0…2000 ppm, 0…5000 ppm and 0…10000 ppm.

Application of GMM112


Types Of Carbon Dioxide Products - Fixed Installations/OEM Products

  • GMM111

  • GMM112

  • GMM220

  • GMP231