Air Condensation

[abaddonxi]

I've been noticing on those hot days that after a certain time the aircon unit inside the 130 gets covered in condensation and loses some of its efficiency.

Anyone else found this?


Cheers
Simon

[PhilipA]

If it does actually get less efficient , it means it is icing up on the fins in the evaporator. This could be from a faulty thermostat, or the end of the thermostat not positioned correctly in the fins.
If the compressor turns on and off , it may be the position of the sender. If you look in and see that the sender is not right up against the fins , move it closer or between a couple of fins.
I am not familiar with the defender air, but you can often tell by leaving the fan on with the air off. If you can do this , do not be surprised if you get whacked by some chunks of ice.
Regard sPhilip A

[rick130]

<div class='quotetop'>QUOTE</div><div class='quotemain'>do not be surprised if you get whacked by some chunks of ice. [/b][/quote]

https://www.aulro.com/afvb/ https://www.aulro.com/afvb/ https://www.aulro.com/afvb/ https://www.aulro.com/afvb/

[abaddonxi]

Your flying ice cannot harm me.


My wings are like a shield of steel.



















Batfink

[one_iota]

https://www.aulro.com/afvb/



Originally posted by abaddonxi
Your flying ice cannot harm me.


My wings are like a shield of Checker Plate.


Batfink


That's more appropriate :wink:

[Captain_Rightfoot]

Normally they have a sensor on the evaporator to tell if it's icing up. If this is broken, the core can be damaged by the icing, and I don't think it does the rest of the system any good either https://www.aulro.com/afvb/

Also, you may actually notice it not being as cold, or with less airflow as the air can't get around the ice 8O

[rick130]

<div class='quotetop'>QUOTE</div><div class='quotemain'>Normally they have a sensor on the evaporator to tell if it's icing up.[/b][/quote]
really ? as in another thermostat ? I'm curious.
<div class='quotetop'>QUOTE</div><div class='quotemain'>If this is broken, the core can be damaged by the icing,[/b][/quote]mmm, shouldn't<div class='quotetop'>QUOTE</div><div class='quotemain'> and I don't think it does the rest of the system any good either Sad[/b][/quote] if the system uses a TX valve for refrigerant metering it can actually cause liquid refrigerant to flood back to the compressor, flushing the oil out of the compressor and potentially smashing the valves, bending rods, etc. (if it is a recirocating type, scroll style compressors are far more tolerant of liquid)

[Captain_Rightfoot]

Originally posted by rick130
<div class='quotetop'>QUOTE</div><div class='quotemain'>Normally they have a sensor on the evaporator to tell if it's icing up.
really ? as in another thermostat ? I'm curious.
<div class='quotetop'>QUOTE</div><div class='quotemain'>If this is broken, the core can be damaged by the icing,[/b][/quote]mmm, shouldn't<div class='quotetop'>QUOTE</div><div class='quotemain'> and I don't think it does the rest of the system any good either Sad[/b][/quote] if the system uses a TX valve for refrigerant metering it can actually cause liquid refrigerant to flood back to the compressor, flushing the oil out of the compressor and potentially smashing the valves, bending rods, etc. (if it is a recirocating type, scroll style compressors are far more tolerant of liquid)[/b][/quote]
Excellent ... someone who knows what they are talking about https://www.aulro.com/afvb/

As to point one, all our household airconditioners have a thermostat sitting up against the coil. I presumed this was to tell not only the exit temp, but if the core is freezing.

One of our aircons had that sensor fail, and it was turning the whole core into a block of ice 8O. All the above is what the guy told me that came out to rip me off... ouch.. I mean fix it 8O

[rick130]

I think that the sensor (probably a thermistor) you are describing, without actually knowing the make/model, etc, is just a straight air temp sensor, (it would be sitting just above the coil, on the return air side) and its function is the same as the thermostat on your fridge, car air conditioner, etc.
If, for whatever reason, this fails in the closed position (or equivalent for an electronic sensor), the simple fact of leaving the compressor running all the time will create an ice up in the evaporator. (most nearly all domestic and commercial refrigeration systems rely on what is called an 'off cycle defrost', as their evaporator temperature is generally quite a bit below zero )
Sometimes we actually mount the sensor in the coil, and switch the compressor according to coil temperature to give a particular air temp (your basic cyclic defrost house frig is set up like this) as this tends to reduce the chance of freeze ups that can happen under high load conditions (eg, high levels of hot stock dumped in a cool room on a hot day)

With the more sophisticated electronic controls they can be set so that if they sense a temp below the normal running temp for X amount of time, alarms will trigger, etc as a safety mechanism, but your basic thermostat doesn't function like this.

[weeds]

i get condensation on the inside unit as well, my has been modded and have some questions

i have not looked at a defender with the correct switches in place for its air-con, must do one day, so i'm only going off the previous owner.

when i brought my rig the previous owner pointed out that the thermostat dial/round thing that normally sits beind the fan switch/dial was removed as the circuit board had failed for the third time and the air-con shop fitted a thermostat in behind the left hand vent. to adjust i need to remove the air vent and adjust with a screw driver. i have not yet removed the vent to find the termostat yet

questions

1. is this a suitable mod (removing the orginal termostat) or should i change it back to the orginal setup

2. when the compressor cuts in and out the fan speed changes i.e. when the compressor turns on the fan slows down and when it turns off the fan speed increases, is this normal. i was going run a dedicated wire via a relay to the fan and have only one speed flat out, would there be any problems with this?

3. to help out i an going to install either plastic or perspec to the cargo barrier to help reduce the area the air-con needs to cool

4. say on a 35 degree day does anybodies defender air con cope, its normally cooler for us to wind the windows down

[hiline]

<div class='quotetop'>QUOTE</div><div class='quotemain'>4. say on a 35 degree day does anybodies defender air con cope, its normally cooler for us to wind the windows down[/b][/quote]


mine only really works well on a long drive

forget the short trips to and from jobs and stuff (130 dualcab)

[p38arover]

Originally posted by Captain_Rightfoot

Excellent ... someone who knows what they are talking about https://www.aulro.com/afvb/

Oi! We'll have none of that in here! This is a family forum. https://www.aulro.com/afvb/

Ron

[rick130]

<div class='quotetop'>QUOTE</div><div class='quotemain'>1. is this a suitable mod (removing the orginal termostat) or should i change it back to the orginal setup [/b][/quote]

I'm not totally up to date with auto air, but replacing the t/stat sounds fine to me.
The fan speed change thing shouldn't occur. Sounds like a voltage drop of some description happening.
The air con used to work ok in the CC, back when it worked. https://www.aulro.com/afvb/ I removed the condenser as it was chock a block full of grass seeds, etc, decided it couldn't be cleaned, priced a new one and........that was three years ago. :oops:

[PhilipA]

In my original answer I didn't really address the condensation thing as this is unimportant.
If you have high relative humidity and high temp the dew point of the air will be above the temperature of the outside of the aircon, and you will get condensation and drips. This is normal and unavoidable.
So do not worry about this aspect.
I have seen cars in Dubai where it is 50C and 90% humidity, be covered completely with condensation in the afternoon, and need the wipers .

Its only if the performance declines you should worry. Now someone has said that the defender aircon has an adjustable thermostat. If so then the thermostat should be turned "up" like in a fridge when you want it warmer.
If you have it on fully cold on a hot/humid day then you will get icing, particularly on a slow fan speed. Low "cold" thermostat setting should only be used with high fan speed on low humidity days.
To answer the recent questions.
Any thermostat will do as long as it switches on and off.

You have a poor installation, if the compressor clutch and condensor fans take enough power to slow the evaporator fan.You can run the fan on high if you like but it sounds more like you should run a specific relay to run the condensor fans directly from the battery rather than the evaporator fan.

Sounds like the Defender air is as bad as the old Rangie air. When in Saudi , I used to silastic all the places that air could escape. Fitted more sound/temp insulation on the floor and bulkhead.
Another area that perhaps could help is to put in better fans for the condenser. without having seen one I do not know how efficient they are, but certainly if they are not a high enough capacity then the air will not work well. Fans which are dying will also place a high electrical load if the bearings are dying, so check that they spin freely.
regards Philip A

[Captain_Rightfoot]

Originally posted by hiline
<div class='quotetop'>QUOTE</div><div class='quotemain'>4. say on a 35 degree day does anybodies defender air con cope, its normally cooler for us to wind the windows down


mine only really works well on a long drive

forget the short trips to and from jobs and stuff (130 dualcab)[/b][/quote]
On a 35 deg day mine keeps up.. but you can't yourself think https://www.aulro.com/afvb/

[blitz]

for the non-fridgy type people "Dew Point" is the term used for when condensation occurs.

Relative Humidity is the amount of moisture a cubic metre of air can hold at any given temperature.

I have no personal experience with the 130 Air-con but I do remember working on a Country during the build up (Umm about 15 years ago) and it used to have clouds coming out of the vents on anything below flat out.

Whith out getting into techno babble this was because of the air speed, humidity, and the temperature of the evaporator - air speed slow, temp low, humidity high 90% plus

everything was cleaned, gas charge correct, TX valve Ok ( Refrigerant flow control device), Rang Mr Landrover and his response was said "and your problem is??"

So I gave up told the customer that it would happen from time to time in very humid conditions and just tell the kids it's because you are going so fast. He laughed and was happy

Blythe