What is the difference between r404a and r134a

Students Click Here. Related Projects. What is the difference between a refrigerants and Ra refrigerants? Which would be more efficient for a low temp. You may wish to check out one of the refrigerant websites. Dupont has some good info.

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Download Now. What about all that RA that is already in use? Are we stuck with low efficiency and emissions of a high GWP gas for the life of these plants? The good news is that there is a cost effective strategy that can be implemented on many plants that can make a significant reduction to running costs and to greenhouse gas emissions.

In a carefully planned retrofit programme, a switch to one of these refrigerants can have 4 separate benefits:. A few minor design changes may be required e. Some small investments in valves, joints and seals will in many cases reduce the historic rate of refrigerant leakage substantially — a 50 per cent cut in leak rate is a realistic target.

There are many examples of where this process has uncovered previous problems and lead to overall energy savings well above the 7 per cent to 12 per cent target. Combining these benefits can reduce the direct global warming impact of the old RA system by as much as 75 per cent and reduce the indirect electricity related CO 2 emissions by a further 10 per cent to 15 per cent.

The reduction in electricity use provides very useful cost savings. The payback period for a retrofit of a typical supermarket system will be in the range of 3 to 5 years. Given the enormous pressure to reduce CO 2 emissions throughout Europe, it is good to find an opportunity that will deliver significant greenhouse gas reductions and add extra profit to the bottom line!

Some end users are missing this excellent opportunity for short term greenhouse gas reductions. They are concentrating on a strategy for their new equipment, for example using CO 2 on new systems. This is an effective long term approach, but will only take effect slowly, as old plants are replaced.

Most supermarket refrigeration systems have a life of 15 to 20 years. It is important to have an investment programme that combines the best refrigeration strategies for both new and existing plants. This is vividly illustrated in the graph below. The graph shows 3 different strategies that could be used by a supermarket company that owns many stores:.

All old plant reaching end of life is replaced with a very low GWP system. The figure clearly shows that emission reduction in the early years is much greater with Strategy 3 than with Strategy 2.

The overall savings achieved over 20 years is equivalent to the area under each curve — which is also much larger for Strategy 3. The significantly improved savings are summarised in the table below.

During the first 10 years the dual strategy Strategy 3 achieves twice as much emission reduction as the strategy that only addresses new plants Strategy 2. Because the energy efficiency is improved when RA chill systems are converted to RA or RF, these extra emission reductions are achieved at lower overall cost.

We are in an era of increasing concern over climate change. All European countries are introducing tough policies to reduce greenhouse gas emissions. Refrigeration plants have two types of GHG emission — from the energy they consume and from refrigerants that leak. But it has a very high global warming potential and is not particularly efficient — the time has come to stop using RA in applications where better alternatives exist.

For new plants, a number of approaches can be considered to improve efficiency and to reduce leakage related emissions. Big step change improvements can be achieved, especially if energy efficiency is maximised.

New plants will often be running for more than 20 years — so it is vital that every opportunity is taken to make cost effective improvements. RA should be avoided on all new plants. You'll need different metering devices too. Personally, I think sucks. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. In my neck of the woods, A costs alot more than A. Cap tube restrictions in my opinion are from the oil and high head pressure and high temperature.

My guess is that you would see alot more restrictions using A in cap tubes. In fact A does not work good in cap tube applications due to glide. I have changed a few compressors on them not on the same unit. Not really sure if it was bad compressors or a cap tube is a bad idea.. We dont have the account, so i dont know how long those compressors lasted or if more had died..