A/C line insulation

djb383 · Post by **djb383** » Sun Jul 08, 2007 7:04 am

Supposedly, insulating the low pressure A/C line will give better cooling. Here is my observation and how I did my test. First thing I did was to cut the correct lengths of insulation so I could could install them as quickly as possible after making my baseline test in order to complete the "insulation installed" test under the same driving conditions (ambient temp and humidity). Each test run covered a 11.1 mile loop, mostly at 70 mph, thermometer in dash vent just to the right of steering wheel. I tested my thermometer in a glass of ice water - it indicated 32F. First, or baseline, test: Completely stock, no insulation, Weather Channel showed 25% humidity, left house at 3:20 pm, A/C on max, dash temp showed 97F, returned to house at 3:32 pm. Lowest observed temp was 38F - No InsulationSecond test: Insulation installed, Weather Channel showed 24% humidity, left house at 3:41 pm, A/C again on max, dash temp still showed 97F, returned to house at 3:53 pm. Lowest observed temp was 38F - Insulation InstalledMYTH BUSTED! Let the flaming begin. LOLclick

keithvibe · Post by **keithvibe** » Sun Jul 08, 2007 7:41 am

yea, i honestly noticed NO difference with or with out the insulation. but it only cost me 2bucks for the insulation so no harm done.

Mario · Post by **Mario** » Sun Jul 08, 2007 7:42 am

The only reason for insulation on the low pressure line is mostly for condensation purposes only. I could never imagine (much) colder air.

zionzr2 · Post by **zionzr2** » Sun Jul 08, 2007 9:19 am

my results have already been posted, but all I will say is that individual results may vary.

djb383 · Post by **djb383** » Sun Jul 08, 2007 11:58 am

Absolutely, results will vary. Were your results/comparisons obtained the same day, same time of day, same driving conditions (speed), same ambient temp and humidity, etc., etc.?

prathman · Post by **prathman** » Sun Jul 08, 2007 12:37 pm

Thanks for the detailed report on your findings under well controlled conditions. One reason why results may vary is that many AC systems cycle on and off to avoid freezing up. Your minimum air temperature of 38 degrees indicates that your system seems to be operating very well both with and without the modification. If the system is cycling to avoid frost formation then even if the modification improves efficiency slightly it wouldn't show up as a reduction in temperature but would instead change the fraction of time that the system is on vs. off as it cycles.AIRC, zionzr2 reported air temperatures of over 50 degrees before the modification and even afterwards they were still at least 40 degrees. If the system isn't working as well as yours, it may never get cold enough for frost formation to be a problem and can therefore run more continuously instead of cycling. In that case any improvement in efficiency would show up as a lower air temperature. If this is the reason for the varying results, then the modification would mainly be of benefit to those who have AC systems that are relatively weak for some other reason.

northvibe · Post by **northvibe** » Sun Jul 08, 2007 1:56 pm

I agree with prathmans post above, my ac was weak from purchase, doing this mod and testing the same day right before and then after install showed/felt improvment. I have a 2004 vibe, maybe they changed something in the 05's..or my ac collant stuff is weaker since its a older car.

djb383 · Post by **djb383** » Sun Jul 08, 2007 10:29 pm

Maybe another test is in order?

northvibe · Post by **northvibe** » Sun Jul 08, 2007 10:38 pm

someone with a 03 or 04 should test this again, I zion's was a 04...so maybe there is something to look for??

yippeekyaa · Post by **yippeekyaa** » Mon Jul 09, 2007 7:28 am

Try repeating the test with ac on normal. "Max" setting simply closes a valve and which puts the airflow in recirculation mode. This recirc mode will not get the air as cold on a long term test as normal.

djb383 · Post by **djb383** » Mon Jul 09, 2007 7:40 am

Quote, originally posted by yippeekyaa Â»Try repeating the test with ac on normal. "Max" setting simply closes a valve and which puts the airflow in recirculation mode. This recirc mode will not get the air as cold on a long term test as normal.Do what! That's why its called MAX. It recirculates the cooled air from inside the car thru the evaporator, not the 97F outside air (in my test) thru the evaporator. MAX will always make for a cooler vent temp than the normal setting.

yippeekyaa · Post by **yippeekyaa** » Mon Jul 09, 2007 8:40 am

Please reread where i stated "long term test". Your testing procedures outlined were exactly that. It also may be a geography issue. 97F outside air where i live will have a similar humidity lvl. Where in your location i see you deal with 24% humidity at that temperature. On a trip in this area with it on max the inside of the car gets muggy fast and the air certainly doesnt get very cold either. Put it on normal and the temp drops and it gets comfortable.

prathman · Post by **prathman** » Mon Jul 09, 2007 9:26 am

I share djb's confusion on your comments regarding 'max' vs. 'normal' AC settings. First, my Vibe doesn't have any control actually labeled as 'Max' but the equivalent is to turn on both the AC and the Recirculate buttons. This takes the already cooled and dehumidified air from the cabin and cools it some more rather than starting with the hot and humid outside air. This should result in the coldest (and also driest) possible air out of the vents which is why many cars label that control setting as 'Max AC.' In my experience that's exactly how it works in practice. On most days the AC works fine without using the recirculate setting, but that setting does help on the hottest days. It was much more noticeable on my Corolla which had a very marginal AC. Used in the normal mode it hardly ever got the temperature down to a comfortable level. But with the lever set to the recirculate position it was pretty effective.

djb383 · Post by **djb383** » Mon Jul 09, 2007 9:42 am

Quote, originally posted by yippeekyaa Â»Please reread where i stated "long term test". Your testing procedures outlined were exactly that. It also may be a geography issue. 97F outside air where i live will have a similar humidity lvl. Where in your location i see you deal with 24% humidity at that temperature. On a trip in this area with it on max the inside of the car gets muggy fast and the air certainly doesnt get very cold either. Put it on normal and the temp drops and it gets comfortable.Get your thermometer out and start testing. My money says you'll prove to yourself why it's called MAX. How did we go from insulating the low pressure line to MAX vs NORMAL. And thanks prathman.

yippeekyaa · Post by **yippeekyaa** » Mon Jul 09, 2007 10:00 am

Quote, originally posted by djb383 Â»How did we go from insulating the low pressure line to MAX vs NORMAL. And thanks prathman.Because you saidQuote, originally posted by djb383 Â»Maybe another test is in order?I suggested one.And again it may be a geographic issue. In my climate high humidity is the norm, In yours it appears the opposite is true. That may simply be the difference of opinion here on recirc or not. My experiences with it on recirc at 90% humidity have yielded bad results.

djb383 · Post by **djb383** » Mon Jul 09, 2007 10:40 am

Dude, get your thermometer out and post some facts, not opinions.

drunkenmaxx · Post by **drunkenmaxx** » Tue Jul 10, 2007 5:03 am

who cares about the air temp, what about the performance increase???

djb383 · Post by **djb383** » Tue Jul 10, 2007 5:28 am

I definitely lost some low end torque with the insulation install. Since there was zero difference in A/C performance, I removed the insulation and low end torque is back. LOL, LOL

A/C line insulation

A/C line insulation

Re: A/C line insulation (djb383)

Re: (zionzr2)

Re: (djb383)

Re: (yippeekyaa)

Re: (yippeekyaa)

Re: (yippeekyaa)

Re: (djb383)

Re: (yippeekyaa)

Re: (drunkenmaxx)