Anti-icing switch

[icb]

Hi
Do any of you know the EXACT location of the anti-icing probe in the evaporator case? (please read completely before answering)

I had assumed that the probe was inserted into the middle of the core, but after receiving a brand new evaporator from 4 Seasons, I saw there was no hole for the probe in the side. Looking again at the outer case where the probe enters and at the dimensions of the core, it does seem possible that the temperature probe maybe slides in just under, but in contact with the bottom fins of the evaporator.
So, does anyone know for sure where the probe sits? If this evap core is missing an important feature like a place for the anti icing probe I'll return it. It's going to be a while before I do this job and I don't want to sit on this part till then and find out too late I should have returned it. No opinions please guys, I'd rather have facts!

[Tom]

This should help....

[Tom]

It's possible the hole you see inside the case is just a guide hole, rather than an actual hole in the evaporator. If you want me to pull the case apart and confirm, just let me know. This is a fairly trashed HVAC console -- for parts only at this point, so happy to open it up in the interest of advancing the collective knowledge base.

[Tom]

Here's a picture from an eBay ad...

ebay evaporator.jpg (432.57 KiB) Viewed 933 times

[icb]

Well crap!
As soon as I saw this view in your video I remembered that this is the exact same thing I saw a year or so ago on my car when I stuck my head up in there. There's definitely a hole in the side plate for the probe to pass through, and also a brass grommet around that hole. Immediately south of the hole, where the square part of the case hole is, you can see part of a tubing elbow.

Screenshot_20241213 de-ice location.jpg (142.45 KiB) Viewed 925 times

However, I made a rough measurement from outside the case, and it looks like that hole comes out right underneath the fins, where the blue dot is on the new evaporator:

20241213_140604_scaled.jpg (228.72 KiB) Viewed 925 times

I guess I'll drill the hole out and maybe even put a grommet in there, and not return it, unless it fails the leak test.

This is a couple other views of the 4 Seasons unit, in case anyone's interested. I bought this on eBay, a vendor called partcatalog2. $225.83 to my door, approximately $700.00 less than Porsche OEM, but probably not quite as good quality. It comes with cardboard wrapped around the core, but was still dinged up a bit. Not a huge issue to straighten back out, though. Where the 45 degree corners are supposed to be, the fins are just bent flat to the side instead of being cut off at 45 degrees, but again, that's probably not a huge issue and the extra mass of aluminum that wouldn't otherwise be there is likely a help, not a hindrance.

20241213_140721_scaled.jpg (326.07 KiB) Viewed 925 times

20241213_140749_scaled.jpg (265.18 KiB) Viewed 925 times

Huge thanks to you Tom, for your assistance! Great video, by the way.

[Tom]

@icb not sure if you want to know this or would prefer not to know but I hate not knowing stuff like this and figured it would advance the cause. So, I present you with a definitive answer. Spoil alert, the capillary tube is embedded within the fins of the factory evaporator.

[icb]

Ugg. You're right tom, I prefer to know for sure. Thanks!

[JerVegas]

I was just about to order the Four Seasons evaporator. Is there a model that DOES have the port for that anti-ice capillary?

[icb]

Not according to them, at least according to the person I spoke to. I haven't installed mine yet, winter and other stuff got in the way. I don't know if I'm going to install the oe sensor just below and in contact with the evap fins, or try to somehow drill that hole without damaging the fins, or make an arduino based custom icing sensor with a thermocouple epoxied between two fins in the correct location. The sensor is just a temperature dependent dry contact closure carrying the compressor coil current after all, not a big deal.

[Tom]

Not according to them, at least according to the person I spoke to. I haven't installed mine yet, winter and other stuff got in the way. I don't know if I'm going to install the oe sensor just below and in contact with the evap fins, or try to somehow drill that hole without damaging the fins, or make an arduino based custom icing sensor with a thermocouple epoxied between two fins in the correct location. The sensor is just a temperature dependent dry contact closure carrying the compressor coil current after all, not a big deal.

Curious if they had any explanation for not having a provision for the de-ice tube? What did they say to do? Or is it just a screw up?

I bet you could tap into the existing temp sensors, feed them to an arduino, and use them to calculate a close approximation to the evap temp. Honestly, just cutting off the compressor when the vent temps go below about 35-40 would probably be good enough, though that cut off might depend on your local climate...