Servicing Air Conditioning Systems

It’s great to hear you got the Fieldpiece kit you just stepped into a new league it might be a while before you get used to the superheat or sub cooling.

Also nice to stick temperature probes or sometimes you just cannot keep your hands all the time while the vehicle is running to look at the temperature of refrigerant lines.

there’s two tests for some oils.

they used to be the old chemical test that would turn colors when we were changing over from R 12 to R134. The chemical test you take a sample you put it in a small bottle that had one chemical then you would add chemical be you would shake it up and down and let it sit and it would turn a particular Color that you would match on the chart to tell you after you’ve done a retrofit how much contamination of mineral oil you had

The same test is available for POE oil

then there was a hygrometer that uses a light spectrum prism that would have a shadow cast on what looked like a gun scope with lines for elevation but there was actually numbers and you could read the percentage of a mixed oil.

if it was Pure POE you would see the line fall on one number if it was pure PAG it would fall on another number if it was a mixed contaminated it would fall somewhere in between.

this was a method I used to use back in the early 90s when we started doing retrofits from R12. Converted to R134.

Making your own pulse width modulator is the easiest and cheapest way to go you could do it with a handful of components on your own breadboard.

Or just use a Arduino is another cheap alternative for somebody Arduino‘s might be a little expensive where you are there only $15-$35 here in the USA but I know you have heavy duty import tax in the UK.

And now lately I’ve even heard those restrictions were some countries around the world including some companies in the US have stop selling their products to UK because of the taxes in postal fees.

Yes NAVAC And other companies relabel rebrand and rename their products when they ship them to different countries are used to go to China often with my wife from Shanghai and I will attend the world expos for selling HVAC products and get to see all the products they get purchased and sent throughout the world all the same product just get different names and labels slapped on them.

I even found supposedly the very large 12 CFM NAVAC Pump that I have that’s nearly $3000 sales over in China with a Chinese brand name and identification tag and label on the motor all in Chinese for $735.

The MACS mobile app may not be compatible with your models over in Europe you should send MACS an email and ask.

Solenoid valve is available here and even after market in from vendors directly from China.

I’m going to the MACS expo convention the last day you go out on the floor and get the meat parts vendors some from Asia trying to sell direct parts kits.
There’s a company here in United States called ranshu. They have many air-conditioning parts don’t know if they can ship to the EU it would probably be bothersome and extremely expensive.
But you could probably look at their website just for information purposes and then source your product somewhere else can use ranshu‘s website see what actually is available in the US but not in your country.

 

yes PAG 150 is going to way of the dinosaur.

only meant for the old York and Tecumseh compressor and A6 Frigidaire when retrofitting them over for the early New remanufactured for 134

but now all the new manufactured stuff has their machine tolerances for the 46 viscosity

 

It makes a slight bit a difference a little faster in the beginning.

But once the system gets down to the micron level that’s where little hoses and big hoses or big vacuum pump and little back and pump almost do the same amount of work.

you just get down to a lower vacuum quicker it’s like using a Hummer to pull out a weed in your front yard get it done faster.

 

Yes if either Fieldpiece or measureQuick would allow somebody in the automotive to develop their software geared towards Automotive to let them get into the source code so they can alter the parameters and change the way the software works more geared towards Automotive that would be very helpful.

The only problem with the Automotive cars very too much too many compromises had to be made that force the system to work on your severe situation that would never happen in a normal world for a heat pump at your home that sits still under slow-moving temperature compared to a car that’s a heat pump driving down the road at 60 miles an hour that could drive from being in the shade on the north side of the mountain where it’s cool 10 minutes later pass through a tunnel and be on the west side of a mountain or south side where it’s hot and sunny

with the fan systems that vary the air over a condenser from either pulsating or constant on or variable makes the superheat and sub cooling fly all over the place not steady.
It’s too difficult in automotive on top of that you cannot do it at idle because the compressor is not working insufficient RPM range

and you cannot do it with the vehicle still with no airflow flowing over the vehicle because the condenser was not meant to operate in that mode for efficiency.

Because of the negative pressure created in front of the condenser by the rear fans behind the radiator pushing the hot under hood engine heat wraps and rolls around the front from underneath in any little tiny openings and cracks around the sides of the radiator sometimes even the top of the radiator and then suck back in hot heat re-heating up the condenser when the car is sitting in the store giving you false test results

and just a simple fan is not sufficient to blow air over the front of the car because you have to have a linear fluid flow of air

so you would need a fan for multiple large fans literally going through ducting very large ducting we’re talking three or 4 feet high 6 to 8 feet wide

then inside the ducting you would need straightening veins where you break up the airflow to make it linear and the ducting would have to be 3 to 5 times longer than it is wide it’s a physics thing with airflow to get it straight now so it’s non-turbulent.

Then this air would be directed at the front of the car to put a front pressure on the front grill at the same time having airflow over the hood and underneath under the engine to make a negative draw to bring the air rearwards from the hot air engine compartment instead of rolling around front words.

And any test performed to take measurements have to be performed with the hood closed when you’re using the fresh air mode pulling the air in from underneath the windshield so you don’t bring 140° or 160° air up from the engine compartment right down into the evaporator.

This is where the remote for your peace gauges come in good because then you don’t have to run hoses up underneath the wheel well or from underneath the engine and then attach them to the fittings

But you have to wrap the Fieldpiece sensors in rags to act as an insulation against radiant heat from the exhaust manifold in the high under hood temperatures and then put tinfoil around the rags with the reflective side facing outwards

Because when the sensors get too hot they shut down (ask me how I know)

he’s are all methods and airflow fluid dynamics and thermal dynamics stuff my father taught me when I was too young to fully understand and comprehend but I did grasp base knowledge at a very young age without math.

unfortunately this trade was never meant to have anybody smart actually wanting to know how to diagnose and test things to fix stuff.

This industry was more geared for parts monkeys see part broke take part off open box replace with new part.

The one thing my father taught me when I was young was he told me to look at all the mechanics trying to look at pressures and temperatures with an engine at idle now I was a mistake number one

Or even if they did ever read anything and bring the speed up to 1200 RPMs 1500 RPMs 1800 RPM whatever the manufacturer specified for that particular vehicle as a testing speed for the air conditioning their mistake is they had hood up while it was in fresh air mode taking in 140F or 160°F air giving them completely False superheat or sub cooling or pressures.

But with today’s variable displacement compressors in the way the fans work totally just throw superheat and sub cooling basically out the window

But take for example Toyotas techstream software on the newest Prius you put it in a C test mode where they use their pressure transducers in temperature sensors and they have a firmware or base in hardware software that’s the compressor RPM and fan speeds into a test mode to determine if the refrigerant is significantly charged or not

This is what all cars need for the manufacture to do

just like on the large VRF Heat pump and heat recovery unit in commercial buildings they have a test mode where you go into the software and they use the onboard transducers Heat pump and heat recovery unit in commercial buildings they have a test mode where you go into the software and they use the onboard transducers In temperature sensors to test the system

 

I do get lazy about depressing the low side trailer before hooking up my refrigerant analyzer.

Usually when those customers themselves or the customers took it to a shop that uses the little cans that also contain lubricant with leak sealant and they don’t have just one can squirted into their car they have 23 or four cans and they have so much lubricant as soon as you start recovering out the low side tons of oil start coming out because it’s so over oil be in the system

 

R134a not flammable

what you see in the video is your 12a (brilliant)

 

Those are both excellent pumps manufactured by the same manufacture they just change the name a little bit for the European market like they do around the world with all their products.

The advantage of the DC motor pump is that if the wiring is old in the building small gauge and it has a high voltage drop on start up a normal big pump will stall out and just come in overheat and blow a circuit breaker.

The DC motor starts off inverter driven at a slower lower speed so it doesn’t have a high inrush current so I can start easy.

I have the smaller brother of the 12 CFM DC driven vacuum pump I have the CFM version.

I also own the larger industrial vacuum pump 12 CFM actually capable of going down to 3 µm.

The DC motor vacuum pump you can run and start on the extension cord that would normally be too small to run the larger industrial vacuum pump.

so for you I will recommend the DC motor driven vacuum pump.

The other industrial grade vacuum pump is for somebody like me who literally runs it from morning tonight every day 365 days a year.
I leave my vacuum pump on jobs running 24 seven over the weekend when leaving the job Friday night and showing up back to work Monday morning.

I’m trying to achieve a ultra low vacuum to help my customer systems to be is moisture free as possible. And because I’m a business that charges hourly I need this to happen as fast as possible at $185 an hour every minute cost money.

That is the only reason I have the larger white 12 CFM industrial vacuum pump.

definitely not recommended for the do it yourself person. Especially since it cost near $3000 for this vacuum pump

That first vacuum pump you selected I see many of those burnt out and shop high failure rate it’s good for a backyard do it yourself person for a couple jobs or not important jobs.
A lot of the mechanical shops who are cheap I see by those eBay specials . And when they start losing their vacuum capability the shop doesn’t even know that they’re using a vacuum pump that is no longer working any good it’s spinning it’s making noise but not drawing a good vacuum

 

Understand