Not Cool!

[coughy]

it cost me $145 mine was completely empty
so i know it got the full 650grams
his machine is a all-in-one that weighs it and does the pressures
cost him a fortune but it works well so yes
get them to put in 600 grams and start to monitor the pressures and temps i got 650 and he said no more pressure is high as it can be

[greig]

On one of my older vehicles I had the air con bloke leave a probe in the outlet vent for a day and it was a constant 3 deg.

I don't know where the Mitsu people measure their temps at but a temp as high as 10 deg plus is very high !

[SwampFox55]

PB AC Temp Performance


Background. After reading this thread yesterday I checked the AC temps on my PB. The fan speed was set to 1 or 2 as required, with the 4 face vents fully open, the temp controller set to full cold and cabin recirculation on.The weather was BCN high cloud/smoke, high UV mid arvo,with an OAT of 29C reducing to 27C over the course of the drive. The car is white with cheap grade dealer selected windscreen tint (eg 75% UV).At the first checks the car had been driving at highway speeds for 1hr and the same again for the second set of checks.The thermometer was held about 3cm from the centre vents for between 2 to 5min on 6 occasions, both driving and stationary and with the AC running full time.The car has always been warm inside on a sunny day, even with the AC running at fan speed 2 and it’s often set at 3 or 4 (very rowdy) on 35C plus days just to be tolerable.I don’t know if this cabin air temp has changed since new but it’s certainly been like this over the last six months because I can remember one drive in Oct 15 where I had to run the fan at 4 for the whole 3hr trip just to be bearable.I’d replaced the pollen filter just before the trip with a MM part.After yesterday’s checks I realised we’re like the proverbial boiled frogs and I’ll have to get the AC seen to.

The cargo area temp was read at the end of the trip. I’ve been concerned about the cargo area temps for the dog for some time but unless Coughy had made his post yesterday, I’d never have considered putting a thermometer in the car, let alone the boot (set on the dog cage, out of the sun for that part of the trip).

I’ve always felt a lot of heat coming through the firewall and dash after the engine gets hot as does the RHS floor above the exhaust pipe. Get the engine nice and hot on a warm day then switch the fan off and you can feel the IR radiation coming out of the dash plastic.So you need a really effective AC to counter this heat build-up.When I departed yesterday on what was to be a 2 to 3hr trip, just to get the thermometer out of the way, I’d put it under the floor mat at the back of the driver’s foot well.When I picked it up to commence reading the temps, it read 37C!I had to let it cool down to cabin temperature (26C) before taking any vent readings.It is normal for car floors above the exhaust pipe to get hot but I didn’t realise how much.Remember the outside air temp was only 29C and the floor mat was in the shade for the whole trip.

Readings. So with the AC set to full cold at fan speed 2 on a 29 to 27C day, the face vent temps were 11 to 13C and the cabin range was 25.5 to 26.5C (at waist height; ie hotter at head height) for the whole trip (two 1hr stints at highway speeds).I expect it got hotter inside as the UV increased and the interior surfaces heated-up, even though the OAT was decreasing as we got closer to the beach by the end of the trip. To summarise, with the AC set to full cold on a 28C partly cloudy day, the averages were 12C at the vent, 26C in the front seats (at waist height) and 31C in the cargo area (50cm from the floor) and let’s not forget, 37C on the RHS floor!

If you compare these temps with those above from OJ for the NW Pajero (ambient 25C = 11.5 - 14.1C at AC vent) and consider the Service Manual’s specified ‘garage ambient temp’ as equivalent to the 'stabilised cabin temp’ of 26C yesterday (because recirculation was selected), the vent temps are within specification. Well sorry, I just can’t believe this is possible!If you look at the temp ranges provided by Giddyup and OJ above, they all look very uncool to me.Really, on a 45C day is a vent temp of 40C acceptable (as per Giddyup’s Challenger specs)?Maybe if you’re not in the car it’s OK!I don’t think those specs are acceptable to any reasonable person, they are just what Misty got out of the AC system it installed – which is not the same thing.

Attached are a couple of pics of the vent temp (at 1st stop) and boot temp (at 2nd stop), both when stationary.I didn’t get a photo of the cabin temps because my wife was taking the readings while I was driving.


SF55
160127

[itsamitsi]

Those temps are crap. I haven't checked ours but it seems to work OK as I don't remember complaining about it even when we were out in 47* wind a few weeks ago (as the OS temp reading was displaying while driving in the Yarra Valley) I will drag out the thermometer and do some check meselfs...

[old Jack]

SF55 inspired me to check mine so I took the thermometer from my fridge.

Parked in shade, 31C outside temp, 10 minutes on Recirculate, full cool and fan speed 2 and the temperature at the face vents was just under 10C.



Temperatures measured off the evaporator cannot be lower than 2C as condensation can freeze on the evaporator and then you get no airflow in the cabin vents. By the time the air has flowed through the uninsulated ducts I am not surprise it is only 10C at the exit of the dash vents and higher at rear vents. Any car AC will take some time to reduce and achieve a temperature difference of 15C in cabin temperature compared to outside particularly if the sun is directly shining onto the windows. Extra window tint and light coloured duco helps as does selecting recirculated air. For occupant comfort 22C to 25C and good airflow is optimal. I am not surprised at the temps measured by SF55 particularly in the rear cargo area. The standard single AC units in most cars are only really good for the front passengers. 2nd and 3rd row seat passengers really need a 2nd AC unit if you are to achieve similar comfort levels to the front seats.

cheers, OJ.

[littleriver]

gone are the days of the good old R12 refrigerant... 134a just doesn't cut it

[fester]

You guys complaining about poor air, what model and version of a/c do you have. Like I've said our black XLS with the climate air has no issues at all. We can be frosty cool on a hot day if the air is set at 19 or 20 which admittedly is the lowest settings. Do agree though that rear air is needed in any car for good cooling for passengers. That was a hopeful extra in any car we look at in the wife's eyes for the dog in the back seat and was the only reason we were originally trying to find a cheap 7 seater.

[Bombo]

I've always said that temperature is relative, if it's 40 outside then 30 inside is positively delightful.
I Never expected air conditioning to provide more than a 10 degree differential.

[cookie9]

Slightly off topic but.. Is there any realistic way to improve the insulation of the firewall and especially the drivers footwell? I find the floor heat especially annoying! I have the thick oem rubber floor mats and they get rediculously hot.

cheers

[Kingbrown]

Never mind the heat from the floor pan.
What about the heater core that's directly opposite the a/c evaporator ?
Challenger Heater and Ventilation Unit AC807375AC00ENG.pdf

[old Jack]

Never mind the heat from the floor pan.
What about the heater core that's directly opposite the a/c evaporator ?
[ATTACH]31055[/ATTACH]

Good point KB, I presume that there is a coolant flow control that controls the flow of hot coolant through the heater core and the cooled air is then re-heated to the desired warmer temperature. If this flow control was not working correctly then you could always be re-heating your cooled air. Worth checking for those with an issue.

cheers, OJ.

[Kingbrown]

Nowhere can I find any reference to a control valve for water flow in the heater core. Therefore the heater core would always be running quite hot.

The temperature of the outlet air would thus be modulated by directing air through the a/c evaporator &/or the heater core.

Happy to be corrected if I'm wrong.

What method does a modern Paj use ?

[fester]

Is there anything in the engine bay or on the engine that may regulate flow. One would assume that they could have just a minimal flow to keep the core protected without heating it too much. Unless they just feel it's insulated enough.

[fester]

I've always said that temperature is relative, if it's 40 outside then 30 inside is positively delightful.
I Never expected air conditioning to provide more than a 10 degree differential.

Seriously!! I think that in this day and age that is pretty piss poor performance.

Slightly off topic but.. Is there any realistic way to improve the insulation of the firewall and especially the drivers footwell? I find the floor heat especially annoying! I have the thick oem rubber floor mats and they get rediculously hot.
cheers

cookie, there are plenty of noise and heat insulating products on the market and some pretty good priced the issue is that it can be a pain in the butt in a modern car to rip everything out to get in there and stick the extra stuff on the floor and firewall but it is certainly doable.

[itsamitsi]

Lots of modern cars have no heater tap to shut off water flow only a flap in the heater box to change between hot and cold. I'm not sure what the Challenger runs?