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CHEMAS
16-02-2013, 10:29 AM
Hi!

Ive understand that some people find Climacheck unnecessary because its possible to analyse a refrigerationunit without it. How can I logg or meassure the temperature and pressure at the same time? Is it possible to logg everything in the computer? Of course its possible but how do I do it? Any ideas? I want to make a good analyse and see where I can optimise and show a how much more effective the unit is running.

hookster
16-02-2013, 11:05 AM
Climacheck is a nice piece of equipment but it is as you say just another data collection source and all the smart bit is in the software to do the P/T comparisons.

You can do an analysis with analog gauges, current clamp, voltmeter, temperature and a comparator and a sheet of paper. The more readings the more accurate the information don't forget the ambient conditions.

Digital gauges also collect data and can export to a spread sheet, then write some formula in the spread and you are on your way.

Then you could use a small plc for data collection (this is what the climacheck does), export data to a spread sheet.

It all depends how much time you want to spend on your project or just buy a development project like Climacheck. With time you can make a very intuitive analyser, add some graphing and market it! :D

DTLarca
16-02-2013, 02:33 PM
I'm one of those who thinks gadgets like Climacheck are unnecessary.

Ordinarily we are looking to see whether the system is working as good as is reasonably possible.

On other occasions we want also to know precisely what duty the system is achieving. For this we need to know either the mass flow of the medium being cooled or heated or the mass flow of the refrigerant.

Some people and some gadgets like Climacheck, but not necessarily Climacheck, try to infer refrigerant mass flow by calculating electrical power consumption. Such calculations have to take into consideration the compressor's isentropic efficiency. This is very difficult to do with any acceptable accuracy. And for this reason alone I abstain from the use of such gadgets for the determining of actual system duty estimates. I instead go for more accurate cooled medium mass flow.

Even if with cooled medium mass flow you also have heated medium mass flow - calculating isentropic efficiency is difficult because you still do not know what percentage of compression heat is rejected to places other than the heated medium.

I give a one day talk on the matter and at the end, after one understands how to eliminate all the factors ordinarily making the process seem complicated, techs are able to diagnose the system for best performance possible, or not, by considering just subcool and superheat according to an approach Gary Lloyd calls the TECH Method.

http://www.refrigeration-engineer.com/forums/showthread.php?28453-7-Subcool-amp-Superheat-Problem-Scenarios

In my opinion, the best advice I can give right now, is that if you want to know actual system duty then the money spent on setting up Climacheck is better spent on parts or instruments required to measure cooled medium mass flow to be used in conjunction with a PH Chart for the refrigerant used.

If you only want to know that the system is working as close as is reasonably possible to what it was designed to do, which is a different question to "what duty is it achieving?", then Climacheck is even more irrelevant unless you are not a RAC Tech and do not know any or just can't afford to hire any (in which case neither can you afford a Climacheck visit) and if you can then why not use the money to learn to make the checks yourself.

It's not like the checks to learn are specific to a particular make's model range of which you do not often sell or service - the check procedures are generic - relevant to all systems - they are something like universal rules/laws.

There may be better arguments and evidence out there against my position, of which I am yet to learn, in the mean time I can only make this my best position based on the arguments and evidence presented to me so far.