Ac thermometer type?

[69porsche]

I am looking a LED/DIGITAL thermometer to test my AC coming from the vent-I prefer something that will stay in the vent as well as measure the temp in the car.

What are you using ? brand and model?.....I have tried several but they keep failing me

Thanks in advance!

[Pazuzu]

https://www.amazon.com/gp/product/B007FSG72K/

I stick the probe in the center vent, and set the thermometer on the floor between the seats. It only updates about once a minute, so it's not great for fast changing temps, but it's stable and the batteries last for YEARS.

And, $12 is pretty nice for a 2 temp thermometer.

[69porsche]

Originally Posted by Pazuzu

https://www.amazon.com/gp/product/B007FSG72K/

I stick the probe in the center vent, and set the thermometer on the floor between the seats. It only updates about once a minute, so it's not great for fast changing temps, but it's stable and the batteries last for YEARS.

And, $12 is pretty nice for a 2 temp thermometer.

Thanks-I just ordered it!

[adias]

What should the probe temp read?

[RNajarian]

Here is another option, Harbor Freight $5.99 before 20% discount

https://www.harborfreight.com/instant-read-digital-thermometer-95382.html

[Rawknees'Turbo]

Originally Posted by adias

What should the probe temp read?

That depends on the performance capabilities of the system - a functioning, unmodified 911 system is going to produce temps in the 50s on 90+ degree days and modified systems are capable of temps in the high 20s-low30s in the same type of weather conditions (even lower if the outside air temp is below 90).

[69porsche]

Originally Posted by RNajarian

Here is another option, Harbor Freight $5.99 before 20% discount

https://www.harborfreight.com/instant-read-digital-thermometer-95382.html

Thanks-I have a few of those around as well....was looking for a larger display

[RNajarian]

Actually I did the same. When I was building the A/C system in my car I had one of these thermometers shown below. I ran the sensor on the evaporator to see how cold it was getting, and also taped the sensor to my passenger side view mirror to get outside temperature to calculate the difference from inside to outside.

Good Luck with your project

[69porsche]

Originally Posted by RNajarian

Actually I did the same. When I was building the A/C system in my car I had one of these thermometers shown below. I ran the sensor on the evaporator to see how cold it was getting, and also taped the sensor to my passenger side view mirror to get outside temperature to calculate the difference from inside to outside.

Good Luck with your project

Thanks-Nice avatar! I made a few jumps from a C130!

[adias]

Originally Posted by Rawknees'Turbo

That depends on the performance capabilities of the system - a functioning, unmodified 911 system is going to produce temps in the 50s on 90+ degree days and modified systems are capable of temps in the high 20s-low30s in the same type of weather conditions (even lower if the outside air temp is below 90).

You say, stock systems only produce 50F at the vent? I think that is high. What is the real spec?

[Nick Triesch]

I rebuilt most of my stock system and converted to 134 a. I get an average of 53-55 degre s from the vents on a hot SO Cal day. I replaced the compressor, dryer and the expansion valve. Oh and the thermostat switch from Griff. But to be fair my car is black on black. Really tough to cool.

[Rawknees'Turbo]

Originally Posted by adias

You say, stock systems only produce 50F at the vent? I think that is high. What is the real spec?

I based that number (mid 50s in over 90 degree weather) on my own personal observation when I once had a functioning stock system, and the information I've read from numerous other posters with stock systems running in hot climates. A 911 simply does not have enough condenser space, and no decent frontal area for a typical car a/c condenser, to produce genuinely cold vent temps in hot climates (in stock trim).

[Pazuzu]

Keep in mind, the temp is also dependent on the blower speed. My custom setup with PLENTY of condenser only goes to about 50 degree vent temps on a 95 degree day, but the blower is the Keuhl Windstorm blower, which is wired directly via a relay, so it's getting full battery power at all times (one speed, "rockin' out"). The vents might only be 50-52 degrees, but they blow that 50 degree air into the back seat

Plenty cold. If I had a stock blower on low, it might drop those vent temps 10, maybe 15 degrees.

[uwanna]

Originally Posted by Pazuzu

Keep in mind, the temp is also dependent on the blower speed. My custom setup with PLENTY of condenser only goes to about 50 degree vent temps on a 95 degree day, but the blower is the Keuhl Windstorm blower, which is wired directly via a relay, so it's getting full battery power at all times (one speed, "rockin' out"). The vents might only be 50-52 degrees, but they blow that 50 degree air into the back seat

Plenty cold. If I had a stock blower on low, it might drop those vent temps 10, maybe 15 degrees.

I have to agree with Mike. Lack of condenser volume is indeed a shortcoming of the system, but the pathetic airflow volume of the system is also a major problem. For example, my '90s GM sedan maintains
50 deg vent temps at 95deg 80% humidity and will freeze you out!
The air volume is incredible. Have checked the performance chart in the factory manual and it is performing exactly to spec.
My '80SC AC is not installed at the moment, but I have the Kuehl Windstorm
blower waiting to be installed.

[Rawknees'Turbo]

I have a blower motor from GM trucks & SUVs installed - don't know for sure how much more airflow over the stocker, but is somewhat more. I get 27-28 degree vent temps in upper 90s weather with blower on max, but I do have a 3 condenser system (all with fans). Of course, you guys already know that as I crow about it every chance I get.

The tiny ducting in 911 systems definitely sux - looks like Jonny's evaporator housing/blower components improve on that; will have to reverse engineer that at some point, as I can not even dream of affording his gear.