Initially, natural substances such as methyl ether and dimethyl ether were used in the compression units of refrigerating units. However, these substances were retired following toxicity and safety concerns. Later, safety issues were overcome with the introduction of CFCs. Unlike the former substances, CFC’s were considered safe since they were non-flammable. However, the introduction of these second generation refrigerants raised environmental concerns were they were observed to cause ozone layer depletion (Wallington et al., 1994). Consequently, all ozone depleting substances are being banned from used with companies advised to seek less harmful refrigerants.
CFCs and HFCs contribute to ozone depletion through the destruction of ozone molecules by chlorine and bromine. Due to the destruction of the ozone molecules, there is a reduced shield from ultraviolet B radiation. Due to these emissions one can observe localized damage to plants and animals (Vollmer, 2018). In addition, long time emission of these substances can cause a rise in global temperatures leading to the greenhouse effect. Direct symptoms of exposure to CFs include drowsiness, weakness in limbs and disorientation. Direct ingestion of CFS can cause diarrhea and other gastrointestinal disorders (Vollmer, 2018).
Due to the effect of CFCs to the environment, novel refrigerants have been developed that have a low global warming potential. Potential alternatives include HFCs that have a ozone depletion potential of zero. HFCs have been the most popular refrigerant choice since the 1990’s with application in heat pump equipment, refrigerators and air conditioners (Tsai, 2007).
Nonetheless, a significant number of HFCs have been observed to have a high global warming potential (Sekiya & Misaki, 2000). The global warming potential, in this case refers to the potency of a given compound compared to that of carbon dioxide. Consequently, new refrigerants with low global warming potentials are being developed including hydroflouro-olefin and unsaturated hydroflourocarbons (Mukhopadhyay et al., 2018). In addition, these compounds have been observed to be inflammable.
A common refrigerant in air conditioners is R-134-a. The compound has an insignificant ozone depletion potential and lower global warming potential compared to other HFCs. The compound is common in both automobile and domestic air conditioners and was developed as an alternative to R-12 (Fickle et al., 2017). However, the compound has also been considered for restriction due to its contribution to climate change. In fact, it high global warning potential has led to it prohibition in the European Union since 2011 (Fickle et al., 2017).
Following rising concerns on the impact of refrigerants on climate change, new refrigerants are being developed that are safe and have low global warming and ozone depletions potentials. Such refrigerants include R-290 and R-600 (Choudhari, & Sapali, 2017).
These refrigerants are halogen free and have a zero ozone depletion potential and low global warming potentials. Moreover, these compounds have high energy efficiency although they are highly flammable (Choudhari, & Sapali, 2017).
Refrigeration and air conditioning systems help play an important role in food preservation and maintaining interior temperatures. However, various environmental effects has been associated with the use of these gases. The most recent class of hydrocarbons are the Hydroflorocarbons (HFCs). The compounds which include 134a, 143a and r-152a have been observed to have an ozone depletion potential of 0. Therefore, unlike CFCs and HCFCs, these compounds are not involved in the destruction of the ozone layer (Bolaji, 2011).
To select the best possible refrigerant one would have to make an evaluation based on Atmospheric lifetime, toxicity and flammability. In this case, compounds with high hydrogen content are highly flammable, whereas those with high chlorine and fluorine proportion have a long atmospheric life. On the other hand, compounds with medium chloride and hydrogen levels are highly toxic (Bolaji 2011). Based on this analogy, one would have to consider the environmental tradeoff that is more critical to reduce damage induced by HFCs.
Refrigeration and air conditioning systems help play an important role in food preservation and maintaining interior temperatures. However, various environmental effects has been associated with the use of these gases. The most recent class of hydrocarbons are the Hydroflorocarbons (HFCs). The compounds which include 134a, 143a and r-152a have been observed to have an ozone depletion potential of 0. Therefore, unlike CFCs and HCFCs, these compounds are not involved in the destruction of the ozone layer (Bolaji, 2011).
To select the best possible refrigerant one would have to make an evaluation based on Atmospheric lifetime, toxicity and flammability. In this case, compounds with high hydrogen content are highly flammable, whereas those with high chlorine and fluorine proportion have a long atmospheric life. On the other hand, compounds with medium chloride and hydrogen levels are highly toxic (Bolaji 2011).
Based on this analogy, one would have to consider the environmental tradeoff that is more critical to reduce damage induced by HFCs.
Since the CFC ban organizations have been formulating alternatives that can help reduce the rate of ozone depletion. Through history the choice of refrigerants has progressed from consumer safety to environmentally safe refrigerants (Abdelaziz et al., 2012. Moreover, with the ban of CFCs and HCFCs, there has been an increased focus on the use of HFCs. Although HFC have ineligible effect on the depletion of ozone layer, there have been reported to have high global warming potentials (Abdelaziz et al., 2012). In addition, Some HFC alternatives are highly flammable, thus may pose safety concerns in their usage. Consequently, new forms of refrigerants are being developed that have lower global warming potentials compared to the products in the market. Overall, the use of environmentally friendly refrigerants will help reduce global warming while serving as energy efficient systems.
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