Air conditioner 12vdc/24vdc install

[Dull_Machine1350]

Hello firebat45, thanks very much for the reply.
I have the same evaporator that gilee was using and has a green control wire which goes to control the compressor.
Its unfortunate for me but I've had absolutely no help from the Chinese seller, I've been asking for help via email most days over the past month but only sales people answer and they haven't been helpful.
I'd prefer not go the PWM mode system if I can work out another way of operating the compressor. I'm reluctant to install the compressor/evaporator and condenser in my RV until such time as I'm confident that the system will work. My RV is a new Fiat Avan Ovation M5 built in Australia and I have to do major changes to inside the vehicle to accomplish the aircon conversion. So I need to know it will work before undertaking major changes.
This link gives you an idea of the RV.

Avan_Ovation_M5

Virtual Tour by Dale Hodge | Avan Ovation M5 THE OVATION IS SUPERBLY APPOINTED WITH THE FINEST QUALITY FEATURES AND OFFERS LUXURIOUS ACCOMMODATION FOR THE DISCERNING TRAVELLER. Beautifully crafted timber furniture and deluxe fittings add comfort and functionality to the spacious living and...

view.ricoh360.com

I had tried to make up my own wiring circuit, based on what I've researched myself but it could be completely wrong but I'll post just in case I can get some feedback.
The 4 control wires from the compressor are very small and would take little amps, I know that connecting either of the red, yellow or green to the black wire controls the different speeds. So maybe a 4 position switch would do the job as you suggest.
A couple of days ago the Chinese seller did sent the attached diagram with shows the 2 different modes possible at the bottom of the page.
Mode (1.) shows 5 wires and Mode (2.) shows 4 wires. There is another diagram attached which shows a mode(3.) CANBUS Communication mode showing 3 wires. Note the same wiring attachments are different???
However there are only 4 wires that come out of the compressor. Although there is a 5 wire (white) which has been cutoff inside and which has no connection inside or outside. I think gilee mentioned this also. Very confusing for a novice (me). I have no problem with the installation of pipes, evacuating and gassing up however the electric wiring does have me puzzled.

 

[Dull_Machine1350]

This might be helpful for others who would like to set up a 12 V DC aircon system for their Sprinter RV or any other RV.
I decided to go with the PWM control mode so I decided to research the PWM controller that gilee had used to see if other suppliers had a better price as I thought the PWM controller that was advertised by Automobile AC Parts store was expensive at A$80, after some researching I found the same PWM controller without he ON/OFF switch for 1/4 price, ie under A$20. Thanks for the help with my enquiry.

 

[prelude]

A bit late to the party here

First of all thank you so much for everyone here adding to this fascinating thread. I will admit I do not even own a sprinter van but I found this whilst searching for info on the chinese 18cc 12v AC compressor from treeligo (which is also sold by a number of other vendors, mine came from aspligo). The amount information I have learned from this one thread on how AC's work, and the internal workings of the compressor is insane! That is why I like and prefer forums btw in stead of socials. This type of media remains and is searchable in comparison to social timelines (I run a forum myself as well for that reason but I digress)

I am not sure of gilee is still active on this forum and if he will see this message (and I will try a PM if possible) but I am very curious how he has fared with the AC setup in the end. It seems to be very hard finding pertinent information on the web regarding 12VDC AC systems other than the usual dometic RTX2000 influencer sponsored "tests" at 85f in arizona which is not like 90f+ in humid florida at all.

A few questions have popped up / remain though and I am hopeful that someone has the answers so that this beautiful thread can be updated with even more info.

I searched for information regarding this unit because I bought the one with the 3 settings for speed and I knew there had to be a PWM driven one. I prefer to use PWM since I reckoned I could let the unit run as slow or fast as I would like to try and aim for the perfect speed at which I can obtain an equilibrium. Since the unit Gilee had was exactly the same as mine, just with a different sticker on it, I noticed that the internals were naturally also the same as mine. By looking at his cable I figured it is the same as mine, just connected to the PWM connector inside.

What I did notice though is that there are 3 PWM speeds gilee has tested the unit with and the documentation he found/provided states that 5% is low or 2000RPM, 50% is mid or 3000RPM and 95% is high or 5000RPM. I was under the impression that when controlling the unit with PWM I could effectively choose any RPM I'd like. This does not seem to be the case? Can anyone confirm?

Of course, I could measure the PWM output to the fets from the daughter board since it is very likely that internally the unit is run by use of PWM as well and simply copy the ramp up/down over to an arduino and from there have a variable rate compressor but that is slightly more effort.

I also noticed that the FETs are cooled by the housing of the compressor. This means that a minimum RPM is needed to have suficient cooling but then again one of the pictures gilee made clearly shows an NTC on the PCB with the hynix4504 power MOSFETs. So, the board which holds the FETs which is cooled by the AC in action is also monitored and can be switched on/off or ramped up when needed.

In the end I think that there is a lower limit to the RPM since I will be installing this in my car replacing the belt driven compressor and the TXV will have a certain amount of flow that the compressor needs to meet at the least else it will not cool anything. This is however something that mr. midwestdrifter would be able to comment on. From what I have read on this forum so far he is an absolute expert in AC systems

Thanks,
-P

 

[Midwestdrifter]

This is however something that mr. midwestdrifter would be able to comment on. From what I have read on this forum so far he is an absolute expert in AC systems

Most automotive TXVs can throttle back to about 90% of rated flow and still provide enough restriction for good evap temp. So as long as your compressor makes at least 25% of the factory engine driven compressors rated flow, it should work.

 

[Dull_Machine1350]

A bit late to the party here

First of all thank you so much for everyone here adding to this fascinating thread. I will admit I do not even own a sprinter van but I found this whilst searching for info on the chinese 18cc 12v AC compressor from treeligo (which is also sold by a number of other vendors, mine came from aspligo). The amount information I have learned from this one thread on how AC's work, and the internal workings of the compressor is insane! That is why I like and prefer forums btw in stead of socials. This type of media remains and is searchable in comparison to social timelines (I run a forum myself as well for that reason but I digress)

I am not sure of gilee is still active on this forum and if he will see this message (and I will try a PM if possible) but I am very curious how he has fared with the AC setup in the end. It seems to be very hard finding pertinent information on the web regarding 12VDC AC systems other than the usual dometic RTX2000 influencer sponsored "tests" at 85f in arizona which is not like 90f+ in humid florida at all.

A few questions have popped up / remain though and I am hopeful that someone has the answers so that this beautiful thread can be updated with even more info.

I searched for information regarding this unit because I bought the one with the 3 settings for speed and I knew there had to be a PWM driven one. I prefer to use PWM since I reckoned I could let the unit run as slow or fast as I would like to try and aim for the perfect speed at which I can obtain an equilibrium. Since the unit Gilee had was exactly the same as mine, just with a different sticker on it, I noticed that the internals were naturally also the same as mine. By looking at his cable I figured it is the same as mine, just connected to the PWM connector inside.

What I did notice though is that there are 3 PWM speeds gilee has tested the unit with and the documentation he found/provided states that 5% is low or 2000RPM, 50% is mid or 3000RPM and 95% is high or 5000RPM. I was under the impression that when controlling the unit with PWM I could effectively choose any RPM I'd like. This does not seem to be the case? Can anyone confirm?

Of course, I could measure the PWM output to the fets from the daughter board since it is very likely that internally the unit is run by use of PWM as well and simply copy the ramp up/down over to an arduino and from there have a variable rate compressor but that is slightly more effort.

I also noticed that the FETs are cooled by the housing of the compressor. This means that a minimum RPM is needed to have suficient cooling but then again one of the pictures gilee made clearly shows an NTC on the PCB with the hynix4504 power MOSFETs. So, the board which holds the FETs which is cooled by the AC in action is also monitored and can be switched on/off or ramped up when needed.

In the end I think that there is a lower limit to the RPM since I will be installing this in my car replacing the belt driven compressor and the TXV will have a certain amount of flow that the compressor needs to meet at the least else it will not cool anything. This is however something that mr. midwestdrifter would be able to comment on. From what I have read on this forum so far he is an absolute expert in AC systems

Thanks,
-P

Hello prelude, its always encouraging to hear of another person who is installing the 12V DC aircon system. I've just finished installing the equipment and about to evacuate and gas up the system. Unfortunately my supplier Treeligo Official Store have been unhelpful, bordering on useless regarding the supply of a wiring diagram for the installation of the equipment, this includes the 3 fixed speed mode and PWM mode. I've used the information from Gilee's post to refine my wiring of the installation.
Did aspligo supply you with a proper wiring diagram? Are you using the same PWM controller that Gilee was supplied in his kit?
I've purchased all my equipment separately which has made it a little more difficult.
Unfortunately I got very little (no) help from anybody on this sprinter-source forum which has been disappointing as I had hoped that somebody would help a fellow RV'er.

 

[prelude]

Hey Dull machine.

I did not even bother contacting Aspligo. In the past few decades dealing with the chinese it has become quite clear that most of them only want to sell and in numbers. I can tell you many many stories of sorrow and strife I had dealing with either them directly or mates of mine who bought stuff (sometimes in the 6 digits worth of gear) who never got the support they needed and guess who they were looking for to get it fixed...

Anyway, I digress. In short I took the risk since the pump was 4 times cheaper compared to the exact same unit at t7design. I figured that I would be able to work out how to operate the unit on my own steam and with the help of Gilee's troubles and thus nice pictures I did

I have contacted Gilee and miwesterndrifter seperately in PM's as to not dirty this topic but that also means some useful information is now "lost" behind closed conversations but I will make a nice post in the end of all the details for public posterity. For now: no I did not use the same PWM controller. I am in the process of basically duplicating the climate control of my 1998 range rover including all the transfer functions, if I can manage, into an arduino mega that will run the entire thing. The end goal is to have only 1 AC system in the car due to weight considerations. When driving the climate control will manage the cabin and when stationary the power input will switch automatically to the auxiliary batteries. The air flow will also redirect to the camper as well as the internal temperature sensor. I will also run the condensor and evaporator fans through PWM so as to be as efficient as possible.

Ultimately I would like the "night/sleep" mode to be as quiet and energy efficient as possible. Seemlessly running down both the evap and condensor fans as well as the compressor down to the lowest speed possible. I am even considering removing the top controller board from the AC compressor and replacing that with an arduino as well so as to go even lower in RPM, if that is at all possible.

I am sure no there was no ill will here, if I can help, shoot me a message

-P

 

[Dull_Machine1350]

Hey Dull machine.

I did not even bother contacting Aspligo. In the past few decades dealing with the chinese it has become quite clear that most of them only want to sell and in numbers. I can tell you many many stories of sorrow and strife I had dealing with either them directly or mates of mine who bought stuff (sometimes in the 6 digits worth of gear) who never got the support they needed and guess who they were looking for to get it fixed...

Anyway, I digress. In short I took the risk since the pump was 4 times cheaper compared to the exact same unit at t7design. I figured that I would be able to work out how to operate the unit on my own steam and with the help of Gilee's troubles and thus nice pictures I did

I have contacted Gilee and miwesterndrifter seperately in PM's as to not dirty this topic but that also means some useful information is now "lost" behind closed conversations but I will make a nice post in the end of all the details for public posterity. For now: no I did not use the same PWM controller. I am in the process of basically duplicating the climate control of my 1998 range rover including all the transfer functions, if I can manage, into an arduino mega that will run the entire thing. The end goal is to have only 1 AC system in the car due to weight considerations. When driving the climate control will manage the cabin and when stationary the power input will switch automatically to the auxiliary batteries. The air flow will also redirect to the camper as well as the internal temperature sensor. I will also run the condensor and evaporator fans through PWM so as to be as efficient as possible.

Ultimately I would like the "night/sleep" mode to be as quiet and energy efficient as possible. Seemlessly running down both the evap and condensor fans as well as the compressor down to the lowest speed possible. I am even considering removing the top controller board from the AC compressor and replacing that with an arduino as well so as to go even lower in RPM, if that is at all possible.

I am sure no there was no ill will here, if I can help, shoot me a message

-P

Thanks for the reply. Unfortunately when you contact other members directly then those ideas, suggestions and conclusions don't help those forum members who'd also like to gain knowledge and information. What lead me to the sprinter-source forum originally was that members discussed ideas, problems and results which helps all members.
Previously the discussion of 12v DC aircon builds in progress was very interesting and informative. I'm sure many members and others enjoyed and learnt from this discussion.
Some of your ideas are interesting and I feel sure many members would be interested to read and help with alternate ideas which is what the forum is for.

 

[prelude]

Yes, I agree and that is why I suggested that when I had some pertinent information I would add it here. You see, I did not want to muddy up this topic too much (which we are at the risk of doing already) and, sssht, don't tell anyone, I don't own a sprinter!

But no worries, I am currently trying to find someone who can make me a set of custom piping for the compressor and when that has succesfully been tackled I will be reporting on all my findings in this very thread.

Cheers,
-P

 

[prelude]

As promised, an update with my experiences thus far:

I have been shopping around locally to see who can alter the fittings currently in the car to suit the ones that are on the 12V compressor. My go to local shop for strange and out of the ordinary A/C related things have agreed to fix 'er up for me so that hurdle has been taken. I dug up the spare A/C pipes/hoses from a wrecker that I set aside so that they can modify those and keep the original ones as spares to revert should it ever become necessary.

With those worries settled I started digging into the compressor side of things. First I need to find a spot for it to sit properly and level and try to avoid excess radiated heat. Not an easy task under the hood of a V8 range rover. I decided to move the air box and EAS system and fabricate a bracket so that it sits right near the original air intake and very close to the position of the original compressor as to facilitate with the routing of the pipes and hoses. At a later stage I will enclose the compressor or at least shield it from the engine with an aluminium heat shield. If needed a small 12v fan could be hooked up to the original air intake hole in the inner wing. The documentation of the compressor states that it can get quite warm but I believe that is because it is cooling itself with the return line. I am not sure of it likes a lot of heat when turned off. Most people I guess do not mount the unit in the engine bay but that is the only sport I have left for it so...

The second thing I started working on is the electrical part of things. I had already been testing my high output alternator to see if it could keep up with my CTEK system to charge the lithium batteries and I found that the alternator got worryingly hot at times but with only a FLIR camera and not knowing the emisivity of enameled copper wire I could never be certain. Knowing that the compressor alone will pull up to 90A it was time to see what's what. Now, this information is purely educational since it has no relation to a sprinter alternator I guess but should you consider upgrading to a larger alternator this could still be useful.

I added as much electrical demand as I could find to my setup (without the compressor since it is not installed yet) and got the overall current delivered by my alternator up to 188A. It is rated at 200A and according to the supplier the alternator can withstand 390 degrees or 198c. When using my thermapen tucked between the copper windings the temperature rose to 205c before I pulled the plug. My engine is cooled by a belt driven fan and I made around 1500RPM to get max current. I know normally there would be some air flow due to the fact the car is moving but I am taking the pov that I might be crawling along in desert heat in low range at low RPM and IMHO the alternator should simply be able to deal with that. I have contacted the supplier so lets see what happens. In short: Keep in mind that with the electric compressor and very large loads your alternator needs to be able to withstand all that and not all high output alternators are made equal it seems.

The next thing I started looking into is the cooling of the condensor and in particular the electric fans. Since I will be reusing the existing condensor in my vehicle it is quite a bit larger than the average unit used or supplied in kits that generally use the 18cc 12V compressor. I reckon it is nearly twice the size. The current setup in the car has 2 thermo fans pushing air through the condensor when needed (ie at idle or there abouts) and has a belt driven viscous coupled fan pulling air for engine cooling. The entire pancake looks as follows:

2 thermo fans, push style 12A at full speed situtated at the top half of the pack
A/C condensor, full size
3 oil coolers for engine, gearbox and hydraulics at the top half. (I use a milemarker hydraulic winch so need to cool my hydraulics a bit more)
engine coolant radiator, full size
Shroud and VC fan

Particularly the top half of the stack is quite dense but there is little to no cowling around the different radiators so there are gaps where the air can slip through. This means that the push fans are quite adequate to cool the condensor since they are tucked up quite tigthly to it but are far less efficient to cool the units behind it. Conversely, although the VC fan is barely capable of keeping the engine cool on hot days when idling (getting up to 110c) causing the A/C fans to kick in, even when the A/C is turned off, the VC fan at speed has so much over capacity that it is sufficient to keep the rest cool as well. However, this type of design; barely sufficient at idle but adequate at road speeds means that the VC fan robs a lot of power so I am also looking into replacing that with thermo fans.

I am not sure how to proceed yet, still figuring all that out but it made it clear to me that I need to look into the fan and cowling setup as well as find a way to PWM control said fans. I have seen video's of people with the condensor near the rear axle underneath the van where the fans need to go full tilt and are quite noisy to be fair. I would like to avoid that if possible and thus, as mentioned in my previous posts, control the speed seemlessly from 0-100. In reality there is a minimum RPM you would have to have the fans run since at even lower speeds you would heat the coils up do the the PWM pulses but they would not cool adequately. I think the double size condensor would be benefitial and I could run the fans at a much lower rate. I could also just run the bottom two since they have the least resistance compared to the top two when stationary. I could also run all 4 at a much lower speed for silence. The added benefit of this setup is redundancy; should 1 fan fail I still have 3 left

This thought had me digging through the internet to get as much information as possible. Unfortenately we here as not as lucky as you guys in the US who have many many manufacturors for all sort of stuff so I could not compare all possible fans but I found that Spal is widely available around the world and they seem to make quite a decent fan. I'll save you guys all the nitty gritty details but my current idea is this:

• Remove the push fans from the front since push is less efficient as pull
• remove the shroud and VC fan
• place 4 11" pull fans behind the coolant radiator
• improve ducting across the entire pack to force air through all components
• regulate the fan(s) speed according to ECT, condensor temp/pressure, oil cooler temp

Now, the figures seem to support this setup. Even with brushed DC fans that are fairly cheap I can get 5600CFM which is suggested on the interwebs to be enough for a V8. These are the units I was looking at: brushed spal The beauty of these things is that they already have a nice shroud around them and I could fit 4 JUST on the radiator. They are also dirt cheap at just over 100 bucks a piece. I would need to control them through a PWM controller which I would have to buy or build. They also produce a nice brushless PWM unit, but they are 3 times as expensive which is quite a lot. These also suck a lot more power it seems weirdly enough.

My experiments with an arduino and a simple high-side switch (type of automotive FET) have shown that you can regulate them quite well but the standard 500Hz (near enough) PWM frequency is VERY audible as a tone coming from the motor coils. More so even on the blowers inside the vehicle. I reckon the frequency needs to be way nearer the 20khz to get out of human audibility. I am aware that some people buy hyunday or volvo PWM controllers which are basically enclosed boxes where you plug the fans into and feed them with power and a pwm signal ranging from anywhere between 10 and 500hz and they do the rest for you. The Spal units als work the same way, you feed them with up to 500hz PWM to tell them what the duty cycle you want and internally they run the motors at a much different PWM frequencies, just as the A/C compressor does I reckon. I would have to look up pricing of those enclosed units vs building my own and then compare the whole to the fans pre-fab.

In any case, the temps are about to go up here (finally) so I am rushing to make at least the bracket for the compressor so that it can be plumbed in and I can start testing with the rest of the cars setup still standard and see what it does, ie. if it can cool the car as is on a hot day at all.

to be continued!

 

[prelude]

Well, that did not work out as planned...

I got the compressor solidly built into the vehicle and I want to test run it for a few seconds to confirm everything is well. I had the top lid opened to check all the connections since I did not feel like having a burned out shunt This way I could also check the LED that is on the print.

I double checked all the connections and switched the thing on and... nothing happened. So back to the drawing board and triple check everything. Being a bit careful I did not want to crimp a random wire to the plug that came with the kit or cut the existing plug of the driver cable so I had put two small clamps on the pins of the plug.

Of course this went well... (not) During all the fidgeting I accidentally reversed the wires and to my surprise the compressor started running with only one wire connected. I rushed to connect the other wire just in case this was harmful to the compressor and... of course a big spark later and the compressor stopped instantly in a puff of smoke.

Quite dismayed I closed the bonnet (after disconnecting the battery) and let it rest there. The next day I was hoping that the PWM part of the circuit was still working and disconnected the small plug from the "3 wire/3 speed" side and used it to connect to the PWM side. I set up my arduino and hooked the power up. Nothing happened of course but as I was checking if the PWM side was not connected properly I noticed a smell and my eye caught an orange glow from the driver board (the bottom one). Rushing to get the power cables disconnected I did not notice a very large current was flowing.

Turns out that one of the FET's shorted out and was burning through. I could net get the PCB off of the aluminum heat spreader but I think it has burned through the PCB, at least partially as well. I could try and replace the FET but I think that would not be a reliable option in the long run.

Long story short: the compressor is bust. That is to say, the electronics are. I did of course contact the supplier (aspligo) to see if they can provide replacement parts but since last week I only got a response that they had to "ask the factory" and that I "must wait". Seeing the experiences of myself and others in terms of support I do not have high hopes and it might very well be that I need to buy an entirely new compressor, which would be quite the disappointment.

This really brings home the risk with these units; no support and no parts and it has really put me off these things. I am probably too invested in getting this to work to not order a new compressor but it does not really feel good. Another one will take a month to arrive and buying one locally, some companies offer them even if they are rebranded at times, but they cost from 1k to 1.8k which is quite a lot compared to buying it directly.

Regarding the alternator, I have done quite a bit more research on the subject and have been in contact with another company that builds 320A versions. They were very helpful and provided detailed temperature ratings for all the different components of the alternator but in the end they were not able or willing to guarantee a certain use case, ie low RPM high current. In the end it was suggested I derate the alternator by 20% at least. That might work out but at a cost of 1250 (euro's) for an alternator with spare parts that was quite a risk to take once again.

In the end I decided to look into the liquid cooled versions of alternators. None were ever build for my vehicle but then again; if I can make em fit it's fine to me. The added benefit is that they are closed and a lot better able to handle dust and dirt that I would be driving through but none of the units that I know of can handle currents in excess of 200A. Whilst reading up on a thread on a canal boat forum I found that the VW phaeton alternator can handle up to 190A and are water cooled. The shape is also roughly the same as my unit so I decided to order one from a scrapyard to see what's what. If it works out I can always mount two of these and have a combined power output of 380A, which I will probably never use

So, this story is not even close to an end but things are happening, even the wrong things. I'll update on this once I have more.

 

[prelude]

another small update.

As was kinda expected, no spare parts are available for this compressor at least not from aspligo but I expect this to be the case for all sellers of this unit. Make from that what you will. I personally am to far invested to revert into a different system at this point so I am looking into alternatives. IMHO I have only 3 maybe 4 options:

1. buy a complete new unit, takes some time to arrive.
2. take the existing unit and replace the inboard BLDC controller with an external one
3. try and reverse engineer the existing PCB's and components and build my own
4. go a completely different route.

the first option is kinda crap since I would be buying a whole unit and be left with a whole unit minus electronics. One could argue that it would provide met with the needed spares in the future perhaps when things start wearing out mechanically.

the second option would maintain the compressor as is but I would bring the 3 wires of the stator out to an external box. This would be more serviceable and allow me to customize the whole setup even further but I do not know how many poles the motor has and it adds yet another piece to the whole pie.

the third option would be the most complex but it would allow the existing unit to remain as is and even allow me to build in more safeguards. I would consider offering the replacement online so that there would be replacements available in the future but the OEM might not like that. On the other hand, china does not care about foreign IP so why should we?

the fourth option is something I do not even know where to begin but would require a lot of redesigning, unless I went back to the belt driven compressor and give up on stationary use.

If anyone knows of spare parts for these units I would be grateful to hear from you! Apart from that the take away for now is: you must really want to build a system like this and accept that the amount of user serviceable parts are limited. I doubt even the supplier can rebuild your compressor and it is basically a consumption item.

-P

 

[prelude]

In the end I decided to go for option 1 since it was the option of least resistance. It sucks to have to buy a complete unit but in the end it worked out since I did not need to change anything else.

So, I replaced the faulty unit with the new one and wired it up even more carefully this time. I placed a relay between the original AC clutch wire and ground so that whenever the climate control requested the A/C compressor it could trigger the electric one. I wired the compressor up to only use the high setting (in three setting mode) to begin with for testing. I will try and use lower settings later on. After a (very) short test run to see if the pump would spin up correctly I called it a day and made an appointment with a local A/C specialist.

Today was the day I could get the custom work on the plumbing done. The guys were kind enough to let me roam through their workshop and "play" along with them, learning as I go and in the end they did not even charge for all the hours I was there. Excellent shop!

The first thing we did was remove the old fitting (and flexible hose) from the condensor to the old compressor and sized everything up. Next we crimped on the new hose and a 90 degree fitting on the other end that would connect up to the electric compressor. Once that was done it was time to deal with the low pressure side. There again we removed the old flexible hose and replaced it with a new piece, using an aluminium 180 degree pipe follow by a 90 degree fitting to the compressor. This way I have enough flex in the system so that vibrations will not break anything.

After a proper vacuum test we decided to put in less refrigerant, 900grams to be exact in stead of the original 1250 since the volume of this compressor is less, reducing the total capacity of the system. We filled the system with refrigerant and let er rip and see what happens. The compressor does spin up ever so slowly (but stops in an instant if the signal gets cut off) but ramps up all the way to max, drawing up to 110A in the peak. With the blowers on full and the climate control set to "LO" (aka full blast ) the air out of the vents was stone cold. The low side showed 2 bar (or 30 psi) and the high side showed 9 bar (or 130 psi). According to the guys this would be good? especially since ambient was around 20c only (68 f)

Driving around in the sun I could see the compressor cycle so there is certainly excess capacity. The real test will be a very hot day and according to the weather report next week thursday we can have a 30+ c day (86+ f) so we'll see what's what then. For now I am confident that it will handle that no worries, the only "problem" could be that to get down from a very hot soaked car to a reasonable temperature will take a bit longer.

-P

 

[AlexCL]

Does anyone have any experience with these units leaking refrigerant? I bought a refrigerant tester and its going nuts at the bottom of the evaporator case. Here's a link (turn the sound on to hear the detector):

https://imgur.com/a/BOPDk00

 

[Franny]

Couldn’t get your video to play (not your fault- the cell service where I live is on the edge). But a few questions:
How long has it been installed? Judging by no drain line connected to the left side of the evaporator, I’m guessing it’s not been used much.

Is the unit blowing cold?
Too little refrigerant it blows warm. Too much and the compressor draws excessive current.

Are you possibly constricting the top of the leak detector? Try putting your finger over the end of the leak detector- you’ll likely see it freaks out.

I’d would expect a leak to be at the lineset connections, not from the vent airflow.

 

[AlexCL]

It's only been installed for a couple days - I had just removed the drain line in order to try to test the air from the drain port.

The unit is blowing pretty cold and the compressor seems to draw an expected amount of current.

Playing around with the detector however made me realize how sensitive the thing is to moisture. I did make sure not to touch anything with the tip of the detector but I think what might be happening is the accumulated water at the bottom of the evaporator is triggering it. I dried everything as best I could by sticking paper towels into the evaporator and plan to test again tomorrow after letting natural evaporation do its work.

I agree - seems like I should be able to see (I put some dye in with the r134a) or hear some other sign of a leak especially when the unit is off and the low side reaches pressure equilibrium with the high side.

 

[Franny]

If it ain’t broke…

My system has held pressure for four years. I just had it running for half an hour to cool off the sleeping area, and it’s still frigid air coming out of the vents.

By the way, initially I thought that low fan speed and temperature set higher was useless. I’d run the fan on medium and the cooling as cold as possible.

Now, having lived solely in the van in southern Arizona since January while renovating a house, I’ve learned that there’s a considerable power savings not having the compressor running all the time. The air coming out of the ducts does remain cold for a pretty long time with the compressor off. Actually, I wish I could delay the compressor even more; it kicks back on while the vent air is still cold.

 

[Midwestdrifter]

Those cheap refrigerant testers can often be triggered by a wide range of hydrocarbon compounds including off gassing from fresh plastic or sealants.

 

[AlexCL]

Thanks for all the intel!

Update:

I got a UV light and found some traces of the dye I added in the evaporator water run off. Any idea if this is normal? They appear to be squiggles in the water. I also notices a couple very small spots on the evaporator coils. I couldn't get a clear picture of the evaporator coils, but here is a video of the water run off under UV light.

https://imgur.com/a/9l86pcY

 

[Midwestdrifter]

It isn't normal to have dye leaking out of the evap, assuming those flecks are dye.

 

[AlexCL]

They were the same color as the dye bottle under UV light. Is there something else it could be? It was really hard to get focus on video/picture as they are tiny flecks and don't seem to gather in one area.