**6. Conclusions**

What is expected of this work is the development of discussions regarding the use and disposal of F-gases, so that they can create more effective control mechanisms, not only to the process of replacement of refrigerants CFCs by HFCs but also to controlling the use and especially the disposal of these refrigerants in a controlled manner, preventing the reuse and release of these types of refrigerants in nature.

The tests performed on ClimaTConT of the UFPA were extremely satisfactory, and with the information obtained from the test bench with chiller, it is possible to realize that the current replacement of R-22 with R-410A is not necessarily the best choice for air conditioning systems, because the various indicators, such as ODP and GWP, do not vary widely, which does not contribute to the reduction of ozone depletion.

In the face of all the information listed, some immediate actions should be taken:

	- The impact of CFCs on the ozone layer is a serious risk to human survival. Therefore, some short-term actions should be taken, such as:
		- 1.Effecting the transition phase where R-12 should be replaced by R-134a, and R-11 by R-123. Other substitutes with ODP less than 0.05 should be used to replace CFCs. It is important to note that HCFCs themselves will begin to be restricted from the year 2004.
		- 2.HFCs and their zeotropic mixtures can be used without restrictions: The R-404A replacing R-502 and R-407C replacing R-22. There are refrigeration systems where these replacements can be made with very small cooling capacity losses and efficiency.
		- 3.Developing control mechanisms for the recovery of refrigerants used in residential, commercial, and industrial air conditioning and refrigeration equipment, such as recovery of fluids for recycling and/or disposal, preventing these fluids from being released into the local environment.

**97**

**Table 7.**

*An Experimental Study of Synthetics and Natural Refrigerants Gases*

mable and must have their concentrations controlled.

of these products into the environment should be avoided.

regulations governing this area (ASHRAE 34 and ARI 700).

R-11 to R-123 R-12 to R-134a

> Ammonia, HCFC-22, HFC-134a

*Alternatives and substitution trends of refrigerants according to their applications.*

tion and maintenance of HVAC systems.

4.Development of studies, individualized, aimed at reducing the refriger-

ant charge used in air conditioning and refrigeration systems.

○ It is important to be careful with the safety equipment required when working with natural refrigerants such as R-290 and R-600a as they are flam-

○ Responsible companies must be required to use basic equipment such as a vacuum pump, refrigerant recovery unit, and precision scale for the installa-

• Popular programs must be created with training and recycling courses for those involved in the installation, maintenance, and operation of HVAC systems.

• During the manufacture, installation, operation, and maintenance of air conditioning and refrigeration systems using CFCs and HCFCs, deliberate leakage

• Avoid emissions of CFCs and HCFCs by recovery, recycling, and reprocessing

It is important that users are aware of the origin of the refrigerant to be used in air conditioning and refrigeration systems or in industrial processes, obeying the standards of purity and quality, within international standards. One must also pay attention to the classification of flammability and toxicity and know the rules and

According to the experience of the members of the UFPA "Resfriar Project," coupled with the knowledge of ABRAVA [14], **Table 7** points out the alternatives and trends for the replacement of the most commonly used refrigerant in cooling and air conditioning systems according to their applications, in the transition or

Considering the actual scenario in Brazil, the lack of reliable information about leaks in air conditioning and refrigeration systems precludes further analysis. In any case, informal data obtained from companies operating in the maintenance

Recycling R-600a, HFO

HFC-404A, CO2, ISCEON, recycling, HFO, HC, R-134a, glycol

> Ammonia, R-134a, recycling, HFO

R-290, R-410A, R-32, R-600a, recycling, HFO

**Application Refrigerant used Alternative Trend**

HCFC-22 HFC-404A, CO2, ISCEON,

HCFC-22 HFCs (R-134a, R-290,

recycling, HFO, HC, R-134a, glycol

R-134a, ammonia, recycling

R-22 to R-134a R-134a, recycling R-123yf, CO2

R-407C, R-410A, and R-600a)

*DOI: http://dx.doi.org/10.5772/intechopen.89119*

of refrigerants.

retrofitting phase.

Domestic refrigeration

Commercial refrigeration

Industrial refrigeration

Automotive refrigeration

Climatization systems

*Source: ABRAVA [14].*

*Low-temperature Technologies*

**6. Conclusions**

**Figure 12.**

• Refrigerant replacement or retrofit:

*Pressure-temperature relation between natural fluids. Source: Danfoss [27].*

What is expected of this work is the development of discussions regarding the use and disposal of F-gases, so that they can create more effective control mechanisms, not only to the process of replacement of refrigerants CFCs by HFCs but also to controlling the use and especially the disposal of these refrigerants in a controlled manner, preventing the reuse and release of these types of refrigerants in nature. The tests performed on ClimaTConT of the UFPA were extremely satisfactory, and with the information obtained from the test bench with chiller, it is possible to realize that the current replacement of R-22 with R-410A is not necessarily the best choice for air conditioning systems, because the various indicators, such as ODP and GWP, do not vary widely, which does not contribute to the reduction of ozone depletion.

In the face of all the information listed, some immediate actions should be taken:

○ The impact of CFCs on the ozone layer is a serious risk to human survival.

1.Effecting the transition phase where R-12 should be replaced by R-134a, and R-11 by R-123. Other substitutes with ODP less than 0.05 should be used to replace CFCs. It is important to note that HCFCs themselves will

2.HFCs and their zeotropic mixtures can be used without restrictions: The R-404A replacing R-502 and R-407C replacing R-22. There are refrigeration systems where these replacements can be made with very small

3.Developing control mechanisms for the recovery of refrigerants used in residential, commercial, and industrial air conditioning and refrigeration equipment, such as recovery of fluids for recycling and/or disposal, preventing these fluids from being released into the local environment.

Therefore, some short-term actions should be taken, such as:

begin to be restricted from the year 2004.

cooling capacity losses and efficiency.

**96**


It is important that users are aware of the origin of the refrigerant to be used in air conditioning and refrigeration systems or in industrial processes, obeying the standards of purity and quality, within international standards. One must also pay attention to the classification of flammability and toxicity and know the rules and regulations governing this area (ASHRAE 34 and ARI 700).

According to the experience of the members of the UFPA "Resfriar Project," coupled with the knowledge of ABRAVA [14], **Table 7** points out the alternatives and trends for the replacement of the most commonly used refrigerant in cooling and air conditioning systems according to their applications, in the transition or retrofitting phase.

Considering the actual scenario in Brazil, the lack of reliable information about leaks in air conditioning and refrigeration systems precludes further analysis. In any case, informal data obtained from companies operating in the maintenance


#### **Table 7.**

*Alternatives and substitution trends of refrigerants according to their applications.*

#### *Low-temperature Technologies*

segment indicate that annual leakage rates can be between 40 and 100%, depending on the frequency of maintenance performed [15].

This work proved that even with the reduction in the refrigerant charge used on the chiller test bench, it was possible to improve the system efficiency by replacing an HCFC refrigerant with a natural refrigerant, following a worldwide trend of reduction of the refrigerant charge used in air conditioning and cooling systems.
