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As central Vic along with the rest of aus has been having a bit of a hot time with the weather, i decided to see what could be done - especially after a local mate of mine was showing off how effectively cold his aircon system was in his EL falcon, and mine was about as effective as an eskimo fart..


With a warm/hot car, his airconditioning was chilly from the vents 20-30seconds of the car starting, and having it idle after moving it to a shady spot, within 5 minutes his cabin was in the low 20s (of a 35 degree day)

My roadster - moving it to the shade (after having been parked unavoidably in an direct sunlight area all day), the air con was cooler but not by a comfortable amount after 30 seconds, and after 2 minutes, was only just starting to be cold from the vents and with 5 minutes of running, the cabin was still uncomfortably hot.

Something had to be done!

A few minutes of reading and learnt that folk can insulate the air-conditioning lines in the engine bay..
I'm seriously questioning the common sense of some engineering decisions having run the compressor AC line right past the exhaust system, 5cm away from the headers, unshielded, uninsulated.. thats pretty dumb, and thats why i like to tweak the car..

I'd gone to a plumbing supplies shop and bought 2x 2meter lengths of pipe insualation, totalling about $10, and with 30 minutes of time and a bunch of cable ties, i'd covered up as much of the engine bay's AC lines as i could. Essentially theres only 20cm of exposed piping under the inlet manifold/alternator area that i cant physcially cover/reach.

I've covered both the feed line and return line.
My engine bay, in city driving on a hot day has reached 89 degrees (having measured it from my previous arduino project) - this is after having the car baking in the sun all day, and then driving stop start through a built up area.
On highway driving the engine bay is only 5-10 degrees above ambient.

This 89 degree bay temp will be heat-soaked into the aluminium AC lines and would be transferred into the fluid which would need to be cooled off by the condenser as well as the heat from the cabin. This just makes the condenser have to work even harder for no reason in order to try and cool..

With the insulation installed, and parked again in a hot day light area at work (still no available shade goddammit), and monday here was 42c.. Starting the car at the end of the day, aircon vents where flowing cold air within 15 seconds of being on. (keeping in mind the internal dash vent piping would have been baked by exposure the cabin heat). Within 5 minutes of driving the cabin temp was in the low 20s.

Anyone contemplating this, just do it. I'm looking forward to a highway trip to see how cold the cabin will actually get!
Also, driving with the roof down (in the 40deg day) and AC venting directed to your feet, you can feel the coolth while driving 60kph..


thicker pipe on left for the AC feed from the compressor, thinner pipe for the return line.

(Engine temps are measured at up to 89 deg at the rear top of the rocker cover - right where the return pipe passes)


The insulation is applied to all exposed AL piping, inc under the condensor at the front of the car.
The wire sitting over the top of the rocker cover is my temp probe - can move it around the bay to check on various temps/locations.

For the results, the price and the 'effort' involved with installing it, i couldn't recommend this enough for everyone with AC.

This is a great example of the type of DIY common sense mod which make our cars a better drive.

Thanks for posting.

I want air con

Another thing to look into is that on teh NB (not certain about NA) the hot/cold air mixer thing operates a door hear the heater core that apparently doesn't close fully (the lever doesn't have enough reach) as a result there's always a bit of hot air from the heater that gets into the vents.

i sussed mine out when i fitted a new HVAC panel and know mines definitely in the right position for the cold air option.

As my bro had installed a miatamania CAI (or whichever the one is that drills through the wiper motor cowling area) initially i had hot engine air coming through in that, until i sealed it (then later put my own version of a CAI in).
I also fitted a foam line on the underside of the bonnet to match up with that cowling ridge thingy as the rubbers there weren't seating/sealing correctly. That foam alone made a noticeable difference in cooler air from the cabin vents.

It all adds up, but fortunately its all very straight forward for an easy saturday arvo fix.

Nice!

While we're on the topic of insulation that assist our air-con units, has anyone tried this?



Does it work? I'm seriously contemplating this given how hard my aircon has to work during summer...

http://www.ebay.com.au/itm/261132662771?nma=true&si=0va6denCEpI4i8l8QXKog5K07ys%3D&rt=nc&_trksid=p4340.l2557&orig_cvip=true#ht_500wt_1203

i'm keen to learn of the results of them too! it looks so plush!

just another mild update for this arvo:
It's "only" 35 degrees instead of 42c today, and the AC cools the cabin to low 20s in well less then 4 minutes (only me driving) with the car left parking in the sun.

I'm now second guessing the need to have a 1-2 litre water sprayer tank for the condenser as it might be too opulent driving with a jacket on at this time of the year..

Another thing to consider, especially for the older R12 systems, is to refill the AC with Hychill HR12 gas.

No conversion is needed and is a direct alternative to R12. It provides a much cooler blow through temp than the regular R134a. Had a refill done recently on my 91 (originally R12), with low 30's ambient, the thermometer the Auto Electrician placed on the vent measured 8.4C.

R134a cars can also run the Hychill alternative.

The NB is not renowned for a "good' a/c. Not sure about NC

I'm betting the NA couldn't possibly be any better then an NB setup.. If you're not afraid of tools Mr M, you should give this a go.

Thanks for the tip doo. I'll do this when I regas my aircon...in the meantime I'm just driving the other car!

I MUST try this!

The bad air con makes me hate driving the car.

How is the pipe insulation holding up near the exhaust? I track my car hard so I have no doubt mine would be almost glowing sometimes!

i've only been able to travel in town to work and back this week. after 15 min of driving (and on the hotter days) i get a whiff of heated something - clearly the insulation. This weekend i intend getting some thick aluminium foil to surround the insulation in that. The insulation is about 5cm away from the header piping. Its the town driving that concerns me more then highway driving too. I have found highway driving, engine bay temps are about 10-15 degrees higher then ambient, more airflow etc.. I'll follow up here with what i do.

I'm also going to sus out a few hydraulics suppliers to see what they have. If it's cheap, i'll give it a go.
I also made a heat shield a few months ago out of a metal sheet. While it made a decent improvement on reducing heat on the intake piping/filter, it doesnt reach down all the way to the AC piping. I'll work on that too : )