AIR COND

[minipete]

I went right through my the AC in my Giulietta 2 years ago, new hoses, TX valve and drier, new Sanden compressor, evaporator and condensor cleaned out with dry Nitrogen.  Cost about $1000.  Had to pull the dash out which would also be expensive job if you couldn't do it yourself.

It now works great, not as good as a Honda but plenty cool enough for the hottest days.

Many years ago my AC guy modified my heater box by making some more holes on the side, he said it allowed more air to get into the box.  While I had it out I made identical holes in the other side and the air flow is greatly increased.

I noticed my parts car has the same mod so it must be common for Alfas.

I'll try to add some photos.

Pete

[colcol]

RE aircon, about 25 years ago when my Alfa 33 was newish, it had rubbish aircon that was a locally installed, the reason it was local was that fitted in Australia was about $1200 [1986], compared to a factory one installed on the production line about $3000, one day i was at an auto electrician buying a battery and he asked me how i liked the 33, i said its ok apart from rubbish aircon, he had a look and said, its a poor quality local one, and that he used to install, genuine ones that are a lot better, but couldn't make enough money doing them, i asked him about the Italian aircons and it sounded a lot better than the one i had, i said to him get me one in and i will have a look at it and if it is any good, i will buy it, if its no good here is $50 for your trouble, he got it in, i looked at it and paid $1000 on the spot, instead of freezing up due to lack of airflow it just kept putting out COLD AIR and it blew out of 5 vents, floor and screen, instead of just 3 vents in the centre, he told me that all the Alfa's of that time, 33's Alfetta's and Guillieta's had pathetic aircons due to the fact they were fitted locally, my aircon took me a month to fit, 2 hours at nights and weekends and it was about the best thing i ever did to my car, Colin.

[lombardi]

Please pardon my ignorance-but whilst having a peak at my air con witha torch,noticed that the air con has a red valve and blue one,i might be wrong but does the blue one denotes its been overhauled previously with new type gas--looks rather newish down there-but suffice to say,does not blow cold air-am interested to see what the experts have to say,or maybe i am way off-heres hoping.Ciao

[colcol]

Re Aircon, if you have an old system up until the early 90's then it uses the old R12 gas, check on the compressor for 2 nipples that are externally threaded and are both the same size, if you have the newer system that uses the new R134 gas  the nipples are usually on the pipes and the nipples [or charging ports as they are known as] are not externally threaded but have got grooves on the outside of the ports for use with quick release charging hoses, like a miniture airline or garden hose  fitting, these port sizes are slightly different sizes to avoid wrong connection of the hoses with would result in major damage to aircon components, you may still have a R12 system that uses "replacement" gases with differing quality and suitability, Colin.

[MD]

minipete,

That modification to the evap/heater box will simply result in drawing more air from the cabin around in circles and further reduce the draft of the air from the central duct over the evaporator coils where this air needs to go in order to scrub out heat (make chill).

I do not advocate doing this at all.

If one is not a purists and you are desperate for air conditioning but there is not enough room under the dash for new equipment, it is possible to do a radical departure from the norm.

Install the evaporator in the boot including the fans and reticulate the ducting from the rear to the front catering for rear seat pasengers along the way.

This is not new and was a practice done in the "old" days. My Berlina had one similar.It lacked proper ducting but it sure made a lot of chill albeit with poor circulation.

[Typhoon90]

Aircon in older cars is never as good as newer cars, so we have to expect lower standards. The design as mentioned in many posts, is just not what it is now. Today, climate control in cars is a BIG design job, everyone wants a car that'll get the cabin down to 20c on a 40c day, if your car won't do it, it won't sell. If you can get an older A/C system to be tolerable on a hot day, it's a good effort!
Aside from all the design constraints older systems had (not factory fitted to all cars, so compromised design of components etc), many small issues can often creep into older car A/C systems, and none of them directly involve the evaporator or gas system itself.
The biggest problem I've seen and rectified on many older cars I've owned, has been incorrectly operating air vents and selector flaps. Even a slight bleed of heated air from the heater core into the air path over the A/C evaporator (or blending into the cool air after evaporator) will significantly reduce efficiency of the whole system, as will control knobs with incorrectly adjusted cables/ vacuum hose leaks etc. Air leaks around blend doors etc are also a big problem, trying to get max cooling usually means recirculating cabin air, so you are cooling air that's already been cooled  a little. If the recirc door is blending outside air, again, less efficient. The same can be said for A/C systems that shut off coolant flow with valves, check the valve is fully closing.
There are many very good older A/C system gases available now and all the shops know what needs to be done for correct gas retrofits (not like in the 90's, when it was a replace EVERYTHING mentality), so go ahead and ask at a good A/C workshop. There are also plenty of retrofit kits available off the shelf for older cars that these specialists can now easily order too.
And always have a dye put into the system, it makes those pesky leaks very easy to find (and there WILL be leaks that are missed, it's the nature of an old high pressure gas system).

[lombardi]

Yes i was right,just spoke to the air con specialist--a blue and red valve does mean air con accepts new gas--booked in for this pm--will let u know how i go,i got to tell u any cold air will do,the humidity in syd is stifling.CIAO

[minipete]

That modification to the evap/heater box will simply result in drawing more air from the cabin around in circles and further reduce the draft of the air from the central duct over the evaporator coils where this air needs to go in order to scrub out heat (make chill).

I do not advocate doing this at all.

I've had my Giulietta since 1986 and put up with pathetic AC for 7 or 8 years till this mod was done.  They said the system could blow a lot more than it's ability to suck air into the box.  I realise it increases the amount of air that is recirculated.  It doubled the cooling ability of my system and I was very happy with it (still happy after 17 years).

He also said that when using AC I should always be on recirculate or the system has to work too hard.

Pete

[MD]

minipete,

Just to kick this along a bit, please explain how a total short circuit of the intended draw through of the chiller coil pack (evap unit) will create more cool given that the fan is now drawing cabin air instead of cabin air over the evap. coils.

I trust you have had the "heater" box apart and have seen the posiition of the evap coils and the heater coils as they are sandwiched together and the relative position of the fan and path location of the intended air path.

It is a given that airconditioning is a recirculated practice and even ducted systems in buildings recirculate up to 95%of the air-nothing new there. Domestic split systems compeltely recirculate all conditioned air.

BTW. An air con. system that has worked at the same temp for 17years without fail has got to be a first. I need to know the details of the workshop that installed it 'cause I'm their very next customer.

[GTVeloce]

I am fortunate enough to have a qualified air-con mechanic as my father. My Alfetta GTV air-con was always, as Clarkson once said: "like an asthmatic breathing through a straw"). We put R134a in for a while, but it did also leak very quickly through the pores of the hoses. When I installed the TS engine he overhauled the existing system. We didn't change too many components but cleaned the system thoroughly (cleaned the drier with petrol etc) and put new oil in. We also also put a different refrigerant in - SP34E. It is 95% 134a and 5% hydro-carbon. It will work without requiring major modifications to the rest of your system and delivers very cold air. It also hasn't leaked out through the pores like 134a did although it has only been a year since the conversion. This sort of work could be done for less money than some of mods mentioned previously but I would still recommend getting someone qualified to do some of the work as you will probably need to vac the system first.

[minipete]

Just to kick this along a bit, please explain how a total short circuit of the intended draw through of the chiller coil pack (evap unit) will create more cool given that the fan is now drawing cabin air instead of cabin air over the evap. coils.

I am no expert so am not in a position to explain it.  When the mod was done it improved the AC a lot.  That was good enough for me.

BTW. An air con. system that has worked at the same temp for 17years without fail has got to be a first. I need to know the details of the workshop that installed it 'cause I'm their very next customer.

I didn't infer that it went for 17 years without being serviced, only that the improvement had had no ill effect on the system in that time.

I can't really add any more.

Pete