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 CO2 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
CO₂ Probe GMP252
Indigo200 Series Transmitters for Vaisala smart probes
