Question please - Car Air Conditioner

[ravip]

At which temperature does your car a/c compressor cut off?

Has anyone measured this? (by sticking a thermometer into the vent on the dashboard).

During day time, in the shade, on maximum cooling setting.

 

[Yellowtail]

On 6/13/2024 at 9:08 PM, ravip said:

At which temperature does your car a/c compressor cut off?

Has anyone measured this? (by sticking a thermometer into the vent on the dashboard).

During day time, in the shade, on maximum cooling setting.

 

I do not think it should shut off on max. 

[MickTurator]

It does not cut out at vent temp.

It cuts out when the air going into the AC reaches the set temp

 

The vent temp with the air on should be very low.

My Toyota had a vent temp of less than 5C

[ravip]

3 hours ago, MickTurator said:

It does not cut out at vent temp.

It cuts out when the air going into the AC reaches the set temp

 

The vent temp with the air on should be very low.

My Toyota had a vent temp of less than 5C

Thank you. This was what I really wanted to know. Mine the temp at the vent is 10°C when the compressor cuts off - this is not sufficient on a sunny day.

As the thermostat is a sealed/fixed type, I am in a fix!

[digbeth]

depends on the models, most a/c in Thailand has no heater core plumbed in, even in supposedly climate control models with temperature readout, whereas proper climate control models will have mix in heat from the heater to lower temperature while keeping the a/c running, useful to remove moisture and fog from the windscreens on rainy days while not needing to set the temperature to too cold 

[Yellowtail]

Does it still blow good and hard? if not, I would check the cabin air filter, the blower and the evaporator coil. If it's getting cold, the compressor is doing its job.  

 

How old is the vehicle? If the condenser coil is dirty, the capacity is reduced significantly. 

 

While the AC works when the vehicle is not moving, the more air that moves over the condenser coil, the more efficient the AC works. 

 

 

[sandyf]

29 minutes ago, Yellowtail said:

Does it still blow good and hard? if not, I would check the cabin air filter, the blower and the evaporator coil. If it's getting cold, the compressor is doing its job.  

Good starting point, the temperature coming from the AC will rise as the filters start to clog up. Should be fairly easy to remove and give them a clean, makes a tremendous difference.

The compressor may well be cutting out due to overheating, I would be surprised if it doesn't have a thermal trip.

[Yellowtail]

27 minutes ago, sandyf said:

Good starting point, the temperature coming from the AC will rise as the filters start to clog up. Should be fairly easy to remove and give them a clean, makes a tremendous difference.

The compressor may well be cutting out due to overheating, I would be surprised if it doesn't have a thermal trip.

The replacement cabin air-filters for my gen 2 Fortuner are 58 baht on Lazada, and take less than five minutes to change, and no tools. Why clean them? 

กรองแอร์คาร์บอน โตโยต้า TOYOTA REVO, NEW FORTUNER, C-HR, CROSS, NEW ALTIS เบอร์แท้ 87139-0K060 รีโว่ นิวฟอจูนเนอร์ ครอส โตโยต้า พร้อมคู่มือ | Lazada.co.th

[sandyf]

6 minutes ago, Yellowtail said:

The replacement cabin air-filters for my gen 2 Fortuner are 58 baht on Lazada, and take less than five minutes to change, and no tools. Why clean them? 

กรองแอร์คาร์บอน โตโยต้า TOYOTA REVO, NEW FORTUNER, C-HR, CROSS, NEW ALTIS เบอร์แท้ 87139-0K060 รีโว่ นิวฟอจูนเนอร์ ครอส โตโยต้า พร้อมคู่มือ | Lazada.co.th

We have a Nissan Nevara which has 2 filters and when I looked a few years back I think they were about 100 baht each on Lazada, may well be cheaper now.

Bit academic, easier to clean them than place an order on lazada and they get replaced on major service. The last time the garage did it I think they used lazada clones, I doubt Nissan have stopped marking their spare parts.

[KannikaP]

5 hours ago, MickTurator said:

It does not cut out at vent temp.

It cuts out when the air going into the AC reaches the set temp

 

The vent temp with the air on should be very low.

My Toyota had a vent temp of less than 5C

That seems very low. Will give you frost-bite!

My domestic a/c throws out air at 17 C.

[KannikaP]

1 hour ago, Yellowtail said:

Does it still blow good and hard?

Hey this is the Motoring section not Soi6 ! 555

[Yellowtail]

2 minutes ago, KannikaP said:

Hey this is the Motoring section not Soi6 ! 555

On Soi 6, "blow" is just a figure of speech... 

[KannikaP]

13 minutes ago, Yellowtail said:

On Soi 6, "blow" is just a figure of speech... 

Or does it prevent the figure from speaking?   555    Let's leave it there!

[ravip]

3 hours ago, Yellowtail said:

Does it still blow good and hard? if not, I would check the cabin air filter, the blower and the evaporator coil. If it's getting cold, the compressor is doing its job.  

 

How old is the vehicle? If the condenser coil is dirty, the capacity is reduced significantly. 

 

While the AC works when the vehicle is not moving, the more air that moves over the condenser coil, the more efficient the AC works. 

 

 

Entire system was serviced and cleaned. So there's no blockage anywhere. Yes, it does blow good and hard, and during night time its quite cold and needs to be reduced.

What I feel is, if I can reduce the temperature by about another 3 - 4 degrees, it will be perfect. 3°C at the vent would be fantastic!

Yes, this particular vehicle is a old Toyota Corolla in very good condition. I just cant find a good tech who really know at what temperature the compressor should cut off and check the thermostat to see if it is working properly, or needs replacement.

[KannikaP]

27 minutes ago, ravip said:

3°C at the vent would be fantastic!

Far too cold.

Snow balls here we come.

[brianthainess]

16 hours ago, sandyf said:

We have a Nissan Nevara which has 2 filters and when I looked a few years back I think they were about 100 baht each on Lazada, may well be cheaper now.

Bit academic, easier to clean them than place an order on lazada and they get replaced on major service. The last time the garage did it I think they used lazada clones, I doubt Nissan have stopped marking their spare parts.

Last time Nissan wanted about 1+K, I got mine from Lazada 108 baht including delivery.

[brianthainess]

I have had only 2 problems with my car A/C. First the electric fan stopped working, second had it re-gassed, 500b no leak was found. First Nissan charged 6k for a new fan motor and was stuffed after 14 months, I brought a new motor from GS batteries for around 1.5K still going  strong after about 4 years.  

[Yellowtail]

3 hours ago, brianthainess said:

Last time Nissan wanted about 1+K, I got mine from Lazada 108 baht including delivery.

And automakers do not make their own filters, so the OEM and aftermarket filters may be coming off the same line, just packaged differently. 

[stubuzz]

On 6/13/2024 at 9:08 PM, ravip said:

At which temperature does your car a/c compressor cut off?

Has anyone measured this? (by sticking a thermometer into the vent on the dashboard).

During day time, in the shade, on maximum cooling setting.

An old Corolla, is it using R12 or R134a refrigerant? 10c at the vent is ok. Did you put the fan on recirculate and test while the car is moving? If not, try again.

The vent temp is calculated on many factors so a tech would not give you a definitive answer to your question. The only way to assess your ac system is by checking the superheat. 

Take a look at the chart below.

 

 

 

[sandyf]

6 hours ago, brianthainess said:

Last time Nissan wanted about 1+K, I got mine from Lazada 108 baht including delivery.

Sounds about right.