What happens when capacity of system is exceeded?

[Tim]

18-2226

[cyfi66]

18-2226

Thanks! Whats the difference between ACKITS.COM and ACKITS.NET? I can find the fittings I need on the .COM website but not on the .NET. When I search the PN from the .COM website in the .NET website it looks like it brings up the right part but its a different PN and no description. Ex: https://www.ackits.com/fittings/35-b130 ... ht-8-13576 vs https://ackits.net/product/45-3503/

[Tim]

Just email the items you are interested in. I can check stock and work up a sales order.

Name, address and phone.

[swampy 6x6]

hi
If u can get your aircon to work better when garden hose water is applied to condenser you have a condensing problem = not big enough
***Remember industrial R12/R134a systems DONOT run the high automotive pressures
****Automotive pressures on R12 in the sixties and seventies ran lower than 180-200. In cool weather down to 150psi
***modern pressure charts produced by auto makers are an absolute joke

A SMALL CONDENSOR WILL MAKE YOUR AIRCON WORK POORLY . TEMPERATURE PULL DOWN WILL BE WEAK /slow

WHY........

Over temp refrigerant = over pressure
1/can be gaseous from incomplete condensing
2/ over temp causes FLASH GAS the high temp refrigerant uses up evaporator cooling capacity BTU to convert the incoming hightemp/high pressure to low pressure /temp refrigerant . EG RUN LOWER,, HIGH PRESSURE AND GET MORE COOLING CAPCITY FROM THE EVAP CORE

3/ under charging due to high head pressures is wrong ,All this does is reduce system capacity in most situations

110f ambient
80% humidity
ENGINE RPM 1500
150psi high pressure
25-35 low pressure
40--45f vent Temp
ALL DOORS OPEN .....!

Service evap core --clean every 60,000miles especially if u have no cabin filter fitted

[tbirdtbird]

Who is this guy????
We are waaaay past all that stuff if you bothered to read the entire thread................
You are just trying to get your post count up.........

[cyfi66]

Thought I'd post an update. I did end up bypassing the evaporator pressure regulator but it didn't really make a lick of a difference.

The innards looked as expected - a piston backed up by a bellows/spring mechanism.

When I drive for a long long time or its not 110+ outside the vent temps come down enough to cause the compressor to start cycling. It already has a built in thermistor on the evaporator to cycle the compressor to prevent freezing.

In general though the performance is not noticeably different. It still takes 15+ minutes to get what I would consider decently cold.

Low side about 40PSI
High side about 250-260PSI
No bubbles in sight glass. Charged with 25oz of refrigerant
@2000 RPM and fan high, recirc, windows open, ambient 110degF

Still wondering if going with the retrofitted 2ton TXV will make any difference or if it would be a big waste of time. Its less about how cold it gets eventually and more about how its warm/cool for so long after you start up. Again, my Nissan Z is a dream, cold within a couple minutes.

If I could find a similar style vehicle with excellent AC I think I'd be happy going that route, I just dont know whats out there and whats really good since its so subjective. I see lots of forum posts that my Lexus has amazing AC, obviously I disagree.

[tbirdtbird]

I reviewed your entire thread, which I remember well from last year.
And you just posted a bunch of parameters ie hi, lo, ambient, rpm, etc but I did not see a vent temp.
You have to work with the peculiarities of your particular car and not compare to an entirely different car.
Along that line, you need all the help you can get, so why not insulate your lines anyway? It was suggested but blown off because "the lines are no closer than any other car"
Now that you have bypassed that silly valve,I am of the firm opinion that for your ambient, and the characteristics of your car, you do not have enough condenser. In other words, your evap is way bigger than your condenser. There is no such thing as too big a condenser. Look at the size of the condensers on residential AC in order to get SEER way up....these things are the size of a separate building. Bohica already commented on your high side in the original postings, go back and read what he wrote, I would suggest.

[cyfi66]

I think you're probably right about the condenser. I went through a similar exercise with my supra I used to have - insulating the low side lines and it made no difference at all that I could notice, that's why I'm not sure of it's worth it.

When I look at the condenser I just get intimidated because of how little room is up there and the brackets for the horn/hood latch etc that I'd probably need to cut. Figuring out the lines is the part I really think would be a challenge given the peanut fittings used on the stock system I probably wouldn't find in aftermarket. I think the only way to add more condenser would be to stack another one in front of the existing.

I don't know if I mentioned the fan setup but it has been upgraded to the hydraulic fan that was only available on the Japanese version of this car. It uses an engine driven hydraulic pump and a hydraulic motor on the fan to drive the fan. ATF is used as the hydraulic fluid. There is a PWM controlled solenoid to control the engagement. Let me tell you this fan pulls major air. Way more than the fan clutch originally on it especially at low rpm, and I have complete control over it electronically. Airflow is definitely not an issue here.

Also this time I didn't record the vent temp, just went off of feel. It's probably around 50 degrees after it has some time to pump down.

[tbirdtbird]

BTW did you ever use a garden hose on the condenser to see if that would bring the high side down?
If hi drops, that proves the condenser or fans are not doing their job, regardless of what you think the fan performance is

Also I again reviewed the entire thread and I think these are the most important points made by the pros:
Per DetroitAC:
1. Increase compressor capacity - i.e. bigger displacement, bigger pulley ratio
2. Increase evaporator capacity - i.e. bigger size or more airflow
3. Increase condenser capacity - i.e. bigger size or more airflow
4. Decrease suction line pressure drop - i.e. bigger size pipes, hoses, fewer bends, fewer fittings, no right angle fittings
5. Exchange heat between suction line and liquid line - i.e. add an IHX
6. Decrease Oil amount

Lots of other ways, but they are hard to implement or tricky.

In general, I would say trying to tweak more performance from an existing vehicle, it's easiest and most common to do #3 first, but the 5 ton unit running off generators can't be beat

Per Bohica:
Overwhelmed system will keep pumping to the HPCO range. So let's say you have 375 psi liquid headed for the expansion device. That would mean the liquid refrigerant was at about 175f when you boil it off in the evaporator.
{think about what this means]

Where there is a will there is a way.

[Tim]

This thread is welcome to keep going. After 6 pages of posts and page, 2 covered it pretty well. I'm not sure how much more information can be posted on this forum to solve this.

It's very hot today in Phoenix. You're not going to see 150PSI on the high side at idle.