anti-renewables heat pump? Disadvantages and advantages

Heating, insulation, ventilation, VMC, cooling ... short thermal comfort. Insulation, wood energy, heat pumps but also electricity, gas or oil, VMC ... Help in choosing and implementation, problem solving, optimization, tips and tricks ...
Christophe
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by Christophe » 10/12/07, 12:16

PITMIX wrote:On a well made installation there are no leaks requiring periodic recharging of the circuit. And whoever reloads an installation saying this is a crook. He does not want to piss off looking for the escape because it becomes more and more difficult.


In this case, all car manufacturers are either crooks or do not know how to make their circuit ...because on car air conditioning periodic maintenance / recharging is necessary... : Evil:
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by PITMIX » 11/12/07, 15:56

Attention the air conditioning of a car is different
There are lots of screw connections and everything vibrates galore. The pipes dry and break ...
In addition there are very fragile seals. Not to mention the compressor oil which is degrading.
The circuit of an auto air conditioning can reach extraordinary pressures compared to a domestic air conditioning. The operating conditions are extreme.
We cannot make the comparison.
In the end the mechanics who make the revisions of the air conditioning are not refrigeration engineers and only trust their machines.
The machine sucks all the air conditioning fluid and re-injects the correct capacity compared to the original quantity recommended by the manufacturer.
It is thanks to this machine that rapid air conditioning assessments can be made because otherwise it is very complex.
The machine costs a fortune but then it is possible to make interventions 4 times faster.
The fact remains that if you know a refrigeration specialist and want him to check your car air conditioning, there are only 2 solutions.
Either your air conditioning is down and you get it fixed by this guy.
Either it is for periodic maintenance and there you have to make sure that he has the machine.

Friend's advice, first of all you must replace the cabin filter.
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by Christophe » 11/12/07, 16:00

OK thanks for these notes.

By the way I always wondered, the (or?) Fluid (s) used (s) in air conditioning is what exactly?

In the event of an accident everything goes into the atmosphere therefore ... one might think that for the greenhouse effect it might not be top ... even if it is negligible compared to the CO2 emitted by the same vehicle.

In other words: have the manufacturers studied special clims taking the accident factor into account or not?
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by PITMIX » 11/12/07, 16:20

In old cars it was R12 very harmful to the ozone layer CFC.
For example the Renault 21, Renault 25 and the other cars of this era turn with that.
Since then, R134a has been used, which has the same characteristics in terms of pressure-temperature relationship, but which is harmful only for the HFC greenhouse effect.

The latest models I do not know exactly but in my opinion it follows the course of domestic air conditioning while remaining within the operating ranges corresponding to R12.
Simply because the R12 had the advantage of having a high operating temperature 45 ° for a relatively low HP 10bar relative.
It prevents too much pressure in the caps in strong sun.
But I have already seen an auto air conditioning go up to 30bar with R12.
It must also be taken into account that no explosive product is required.
Current household refrigerators use isobutane but you can't put it in cars without taking risks.
I do not know all the fluids but the R134a is the last to my knowledge which is the best.
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by jean63 » 11/12/07, 17:35

In old cars it was R12 very harmful to the ozone layer CFC.
For example the Renault 21, Renault 25 and the other cars of this era turn with that.
Since then, R134a has been used, which has the same characteristics in terms of pressure-temperature relationship, but which is harmful only for the HFC greenhouse effect.


Hi PITMIX,

On my R25, the air conditioning has been disconnected (wires on the compressor) for a long time to avoid starting it by mistake and taking energy from the engine for nothing.
If I had to charge it, can I do it with R134a? in fact I do without putting the fan on or lowering the windows.

This air conditioning has become madness on all cars: energy absorption => overconsumption.

It would be enough to make white or very clear cars and the air conditioning is done by itself. I had white and dark cars (navy blue), the interior temperature difference is huge.
When I see the big black sedans in hot weather, I immediately think of the air conditioning and CO2 emitted for stupid looks.
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by PITMIX » 11/12/07, 21:39

Ok there is a transition fluid R409a which is better than R12. It is an HCFC therefore less aggressive for ozone than CFC.
But it seems that the R134a is less bad for the compressors.
So yes you can put R134a (HFC) but you should know that the mineral oil becomes acid when you change the CFC for HCFC or HFC.
It is therefore necessary to properly drain the circuit, evacuate it and even rinse it with nitrogen. Add polyoilester oil and R134a.
I do not know the brands of oil for car compressors. I think these are special oils. Not like compressors for refrigeration. In my opinion the critical point is higher.
Ah yes I forgot the retrofitting of a fridge installation always leads to the premature destruction of the joints. There is a good chance that then there will be leaks.
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by jean63 » 12/12/07, 12:47

OK, thanks for the info.
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by crispus » 12/12/07, 13:35

Christophe wrote:because on car air conditioning periodic maintenance / recharging is necessary... : Evil:

My 806 is 10 years old, bought in June 1997. I have never touched the air conditioning or let anyone do it!
The seller told me that the annual recharge was abandoned at the same time as the more volatile R12. Naturally, car centers are not about to let information filter out. As Pitmix says just change the filter. On mine, there are none, the dealers have removed them: on the 806 they tend to take moisture and mold. The remedy is worse than the disease!

By cons the amount of cold produced has become lower: the air conditioning had to lose a little fluid anyway, but not enough to break it down.

4-5 years ago, she missed, I thought I was running away. But a colleague of auto mechanics advised me to check the pressure switch: I disassembled / reassembled it and have not had any problem since, it must have been a simple oxidation of the lugs or a mechanical seizure ...

I put it on the road even in winter, to demister the windshield. It is in any case advisable to switch it on at least once a month, to ensure the watertightness of the joints.

As Jean63 pointed out, since my car is white, the air conditioning is less stressed than with a dark color. This might explain that...
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by PITMIX » 13/12/07, 09:46

Attention crispus it is exactly the opposite the R12 less volatile than R134a. Just look at the old fridge. They held 25 or 30 years and ended up freezing because the insulation of the walls was hs.
Now they end up breaking because there is no more gas or the compressor is burnt out due to the lack of gas.

The R12 was very easy to detect during a leak with a haloid lamp while the R134a is much more difficult due to the absence of Chlorine it is detected with an electronic sensor not always reliable.
Very often mechanics use fluoricin to detect leaks with a UV lamp, but be aware that this degrades the oil in the compressor and can damage the regulator.

If your air conditioning is not working as well as before you are still interested in having it serviced if you do not want to damage the compressor.
A replacement of the filter drier which acts as a liquid reservoir on the auto circuits and a supplement of fluid would not be useless.
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by crispus » 13/12/07, 14:08

Thank you Pitmix,

Would I have been lied to?

In any case, the drop in cold production dates back to 5 years ago and it still works. I am reluctant to have an intervention done which risks doing more harm than good.

One day for sure the compressor will eventually give up, I just have to unplug it to mount a sunroof. : Mrgreen:
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