Carbon dioxide refrigerant monitoring

Many factors promote the use of CO2 as a refrigerant. The challenges related to process design, high operating pressures and safety issues can be overcome with modern technology.

Carbon dioxide CO2 (R744) is a non-flammable, natural, low cost refrigerant with negligible direct global-warming impact and ozone-depletion potential compared to traditional hydrofluorocarbons (HFC). 

CO2 refrigerant has become more widely used in many applications, for example, in 

  • food and industrial processing
  • cold storages
  • food retail and transfer 
  • sports facilities, such as ice rinks
  • car and residential air conditioning

To ensure safety of people in CO refrigerated facilities, CO2 levels must be monitored in places where potential refrigerant leaks can occur. 

Detecting CO2

CO2 is a non-toxic and non-flammable gas. However, CO2 does not support life and exposure to elevated concentrations of CO2 can induce a risk to life. The effects of various concentrations of CO2 on human health are summarized in the table below.

Concentration effect

350-450ppm

Typical atmosphere

600-800 ppm

Acceptable indoor air quality

5000 ppm

Average exposure limit over 8 hours

3 – 8%

Increased respiration and headache

above 10%

Nausea, vomiting, unconsciousness

above 20%

Rapid unconsciousness, death

 

Unlike ammonia, it is impossible to detect leakage of the colorless and odorless CO2 from the refrigeration system without proper sensors. To ensure the safety of personnel in a CO2 refrigerated facility, CO2 transmitters should be installed in every human occupied space and as close to potential leakage points as possible. 

The number of transmitters should be based on risk assessment. Ventilation and air flow should be considered when planning transmitter installations. 

Carbon dioxide is twice as heavy as air and sinks and pools low to the ground, displacing oxygen in the air. Therefore, appropriate installation locations for the transmitters are at floor level.

The Vaisala CARBOCAP® Carbon Dioxide Probes GMP251 and GMP252 are intelligent, stand-alone probes, especially designed for harsh and humid environments. The operating temperature range of the probes is specified as -40 ... +60 °C. The GMP251 has a measurement range of 0 ... 20 %CO2 while the GMP252 is intended for ppm ranges and has a measurement range of 0 ... 10 000 ppmCO2 . 

The probes are easy to mount outside the refrigerated rooms. The Vaisala CARBOCAP® sensors are accurate and durable. They have excellent long-term stability which will reduce maintenance costs over the years. The Vaisala sensors enable reliable carbon dioxide detection for the wellbeing of people working in CO2 refrigerated spaces or people enjoying an exciting ice hockey game in a CO2 refrigerated ice stadium.

Carbon dioxide refrigerant monitoring related products

The Vaisala CARBOCAP® Carbon Dioxide Probe GMP252 is an intelligent, stand-alone, ppm-level probe for stable and accurate CO2 measurements.

CO₂ Probe GMP252

The Vaisala CARBOCAP® Carbon Dioxide Probe GMP252 is an intelligent, stand-alone, ppm-level probe. It's intended for measuring CO2 in agriculture, refrigeration, greenhouses, demanding HVAC applications, and for plant growth chamber manufacturers.
Indigo520 with probe

Indigo500 Series Transmitters

The Vaisala Indigo500 series transmitters are host devices for Vaisala Indigo-compatible, stand-alone smart probes. The Indigo500 series include multi-functional Indigo520 transmitter and Indigo510 transmitter with basic features.

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