Direct refrigerant leakage

The leakage rate from the air conditioner and the refrigeration system has decreased tremendously and it will continue to decrease in the future. The reasons behind this are many like regulations, financial impacts and the improvements in containment technology.  Many countries have enacted the regulations which mandate recovery of the refrigerant from the system before servicing and disposal, prohibition on venting, etc. Developments in containment technology have contributed to the reduction of the refrigerant leakage rates.

Minimisation of refrigerant charge

Reduction in the refrigerant charge is a great mechanism to minimise refrigerant leakage. This can be achieved through general changes in the hardware of the system and also by optimising hardware to suit the properties of the specific refrigerants.

Nowadays, refrigeration manufacturers have reduced the tube diameters of system heat exchangers. As it generally reduces the internal volume of the system, the mass required for the refrigerant is lowered.

New technology like micro-channel heat exchangers are installed in the automotive system and also begin to appear in the stationary air conditioning systems. This technology will help in reducing the required charge in a system. Further changes in the refrigerant charge can be seen when the system are optimised with the properties of the refrigerant. The best example is optimising for RA, superior heat transfer and lower pressure drop impact will reduce the size of the system heat exchanger.

In the air conditioning industry, all refrigerants are limited to single component refrigerants. Refrigerant manufacturers should develop replacements for these single component refrigerants that meet all the requirements of the air conditioning systems:

•    It should be environmentally acceptable
•    Boiling point
•    Refrigerant should be non-flammable and non-toxic.
•    Should have chemical stability
•    Material compatibility
•    Refrigeration-cycle performance

Criteria to select the refrigerant

Many R-22 refrigerant replacements that are under consideration are not good. The air conditioning industry has experimented with different types of refrigerants.

The mixture component that is selected is based on the final characteristics desired. These characteristics are vapour pressure, transport properties, material compatibility and lubricant.  The proportions of components which are selected are based upon the exact characteristics desired in the final products.

Evaluation of the refrigerant alternatives
Researchers are focused primarily on identifying the possible alternatives to the R-22 and R-502 refrigerants. As a part of the research work, tests were conducted on 19 refrigerants that were identified as potential replacements for R-22.

Future direction
HFCs has zero ozone-depletion as an advantage over R-22 but these refrigerants still have a moderate direct effect on global warming.

It is very important to recognise the evolutionary process. HFC’s are the next step but not the last step in the process.

Scientific data supports the fact that leakage of chlorine from refrigerants is one of the factors responsible for the depletion of Earth’s ozone layer. The air conditioning industry is supporting global efforts to protect the environment by introducing non-chlorine refrigerants.

The efforts to reduce the impact of these gases on the environment began with an emphasis on reducing CFC refrigerants. In the late 1980’s and early 1990’s the efforts centred on the elimination of CFCs, mainly used in foam blowing, cleaning and air conditioning applications.

The reports indicate that there are many replacements for the Hydro Chlorofluorocarbon (HCFC) R-22. Some of these replacements are widely used, while other replacement refrigerants have different operating characteristics than HCFC-22. All these gases eliminate the emission of chlorine and prevent ozone depletion. This helps to reduce global warming greatly.

Direct global warming can become an issue if a refrigerant leaks from the air conditioning system. Refrigerant containment in the air conditioning system will reduce the direct global warming effect. This can be accomplished by designing systems that reduce the stored volume of refrigerants.

Refrigerant decisions are impacted by other regulations that are related to the product application and design. Now it has become important for the users to regularly monitor and understand the impact of the different legislative actions related to refrigerants in their air conditioners.

There are laws to protect the environment, which have made people spend more than ever to have their air conditioners modified according to new standards. People are being hit hard financially as these measures tend to be quite costly.

Chlorofluorocarbons (CFCs) leak into the atmosphere and eventually contribute to the depletion of the ozone layer.  These refrigerants were used in millions of air conditioning systems all over the world. However, they are now being phased out of production.

CFC phase out is the most expensive environmental measure to date. Owners of air conditioning equipment have to permanently replace their air conditioners as CFC production will be stopped completely. They can also modify their air conditioners to use the new refrigerants being introduced like R410A. R410A is an environmentally safe refrigerant and does not destroy the ozone layer.

The costs of CFCs are steadily rising and after a few years, CFCs will not be available anywhere. The new systems introduced with the new refrigerants prove to be far superior when compared to the older CFC systems. The new air conditioning systems have better energy efficiency, lower emissions and zero ozone depleting potential, thanks to the new refrigerants. To prevent and minimise leaks, equipment that use ozone depleting refrigerants must be checked annually.

With the rise in temperatures all over the globe due to several environmental factors, there has been a lot of concern regarding the use of appliances that can harm the environment. With the new environmentally friendly and energy efficient air conditioners, this would not be a problem.

By having an air conditioner installed in your office or factory, you can ensure that the indoor air condition is bearable, especially during the summer season.

Air conditioners are very important for industries that are involved in mechanical work. Employees prefer working in a cool and comfortable environment. There are many additional advantages of having air conditioning in industrial setups. The machines do not become overheated quickly and this increases their efficiency. It also brings the maintenance cost of the machine down and lengthens their average life.

Industrial air conditioners or commercial air conditioners have a higher capacity than residential air conditioners. There are more people in an office or factory compared to a home.

There have been many new innovations in air conditioners. You can opt for natural gas based central air conditioners instead of electricity based air conditioners. This will help you to save money as natural gas is cheaper than electricity.

The operating costs of an air conditioner can be high in the short term, but in the long term it will provide many benefits through improved employee and machine efficiency.

HFCs are becoming the most popular refrigerants these days with manufacturers and users alike. Alternative refrigerants need safety and handling measures, like R-22. The main R-22 replacements are based upon different combinations of HFC-134A, HFC-32 and HFC-125. The toxicity of such chemicals has been analysed and is considered to be much lower than the previous refrigerants.

HFC-32 is a flammable refrigerant and can be blended with HFC-125, HFC-134A and HFC-125 in a way that the blend is non-flammable even under severe conditions. Such features allow continued use of the infrastructure now in place for manufacturing, distributing, installing and servicing existing air conditioning and heat pump systems. Thus it makes a quick, easy and less costly transition to environmentally safe fluids.

The HFC refrigerant options have different performance features

R-134A is a low capacity and low pressure refrigerant when compared to R-22. It requires a greater compressor displacement and bigger heat exchangers to match the capacity and efficiency of an R-22 air conditioner.

Currently, it is only used in larger capacity air conditioning systems which utilise centrifugal and screw compressors.

R-407C has a capacity and pressure similar to R-22. It is a zeotropic refrigerant and can lead to greater concerns about maintaining composition control at the time of distribution, installation and servicing of the product.

You should consult a professional air conditioning consultant to learn more about the refrigerant in your air conditioning system.

Buying an air conditioner is not an easy task, but it is not rocket science either. You just have to look for a few important things before you choose and buy a unit.

Air conditioners are generally of two types. Split air conditioners and window air conditioners are the most common types of air conditioners.

Before deciding on a unit, you should first check the size of the room as the size of your room will determine the size of the air conditioner required. The dimensions of the air conditioner should perfectly suit the size of your room. The size of the air conditioner also depends on the maximum number of people that will occupy the room. If the size of the room is very large and there will be a large number of people occupying the room then you could consider having a central air conditioning system.

You should also check the cooling capacity of the unit. The more BTUs (British Thermal Units), the higher the cooling capacity will be. Cooling capacity is the ability to keep your room cool. A unit that has a high BTU has the ability to keep the room cool in higher temperatures.

The energy efficiency rating is also an important factor to be considered when buying an air conditioning unit. A system that has higher ratings must be selected. You can also save on your electricity bills as units with a high energy efficiency rating consume less energy.

It has become difficult for people to maintain car and lorry air conditioning as the cost of maintaining air conditioners has increased. Millions of people need to service their air conditioners because of the loss of refrigerant through leakage. The costs of CFCs have increased and are expected to increase further, almost doubling or tripling within 3 to 4 years.

Additional steps are also being taken to reduce the amount of refrigerant that escapes into the air at the time of servicing the air conditioners. HFC 134A and R 410A do not contribute to the depletion of the ozone layer and are environmentally friendly refrigerants. These refrigerants are cost effective, energy efficient and low in toxicity.

They are blends of HCFCs which are used in both commercial and residential air conditioning. R22 will not be used in new air conditioning equipment after January 2010. It will only be produced to service existing equipment.

Air conditioning owners should buy air conditioning units that are efficient and have refrigerants that do not destroy the ozone layer. They should be aware of the HCFC phase out. They should consult an air conditioning professional before they buy a new air conditioning unit for office or home use.

R-410 is an important HFC refrigerant that is changing the air conditioner industry. R-410A is a near azeotrope composition of 50% of R-32 and remaining 50% of the R-125.

Research has shown that R-410A to be the best replacement refrigerant for R-22 refrigerant in the new air conditioning systems. Many residential air conditioning manufacturers provide R-410A air conditioners and other appliances. As the 13 SEER residential energy-efficiency regulations came into effect in 2006, all the major residential air conditioner manufacturers have now shifted towards the more energy efficient product line by using R-410A.

R-410A has become the refrigerant of choice for use in residential air conditioners. This is because the refrigerant delivers higher efficiency and much better cooling.  The refrigerant has many benefits which makes it an excellent alternative for use in commercial applications.

To date, optimised system testing has shown that R-410A offers high system efficiency when compared to R-22. R-410A evaporates with 35% higher heat-transfer co-efficient and 28% low pressure drop when compared to the R-22 refrigerant.

There is much debate about refrigerants used in air conditioning units worldwide. While examining the impact of air conditioning and heat pumps, it was found that both systems contribute to global warming. According to the research, the direct impact of refrigerants on global warming is due to the leakage of refrigerants from such devices. The average contribution to the total global warming due to refrigerant leakage is around 3 to 4%. An increase of 20 % in the efficiency of these devices would translate to a 12% decrease in total global warming. It is more than 3 times the total direct effect of the refrigerants.

To reduce the impact of global warming’s influence on future air conditioning and heat pump systems, energy efficiency will have to be increased. Use of R-410A will be the more cost effective approach for manufacturing new air conditioners. R410A will reduce the impact of air conditioner and heat pump systems on global warming. An optimised design will reduce the cost on required refrigerants by 25 to 30%.

There are other choices like hydrocarbons and CO2 but they will make the designing of higher equipments much more difficult since they need a secondary loop and other changes in the systems.

Reduced refrigerant charges that are achievable with the R-410A, have improved the containment and refrigerant recovery significantly. Hence R410A is the most preferred solution for replacing the R22 gas.