Chassis air was very unimpressive today

[ducksface]

It's pretty easy to tell if it's the same as my problem.
Turn it on high fan and Coldest setting.
After a very consistent period of time, I think ours is about 35 minutes, the air will be cold, but it will be a bit dank and the air volume will be much much less.
Turn off the ac but leave the fan on
Air will still be cold, but will warm over a period of 8 or so minutes, and as it warms, air volume increases.
When the air is 60ish degrees(a finger feel) turn the ac back on by pushing the button.
It should all work fine for another time cycle.

We go through this many times a day. It has become second nature. I have, as a lay person, tracked it to an aftermarket valve Thor used, a kenworths part I think. I have the Info somewhere, no guarantee I'll find it and no guarantee it's the problem if I do find it for you... Becuae I'll likely never fix it. It just doesn't bother me to push that switch off and then back on after a while.

[TimmyB]

Originally Posted by ducksface

It's pretty easy to tell if it's the same as my problem.
Turn it on high fan and Coldest setting.
After a very consistent period of time, I think ours is about 35 minutes, the air will be cold, but it will be a bit dank and the air volume will be much much less.
Turn off the ac but leave the fan on
Air will still be cold, but will warm over a period of 8 or so minutes, and as it warms, air volume increases.
When the air is 60ish degrees(a finger feel) turn the ac back on by pushing the button.
It should all work fine for another time cycle.

We go through this many times a day. It has become second nature. I have, as a lay person, tracked it to an aftermarket valve Thor used, a kenworths part I think. I have the Info somewhere, no guarantee I'll find it and no guarantee it's the problem if I do find it for you... Becuae I'll likely never fix it. It just doesn't bother me to push that switch off and then back on after a while.

That doesn't sound like the symptoms on mine. Air flow does not feel reduced/restricted; just not as cold after a while.

[Big-Foot]

In order to maximize the AC in the cabin area, just hang a couple blankets from the overhead bunk down to the floor behind the seats. Put the split in the middle with a little overlap so you can have a walkway through to the coach area...

[Big-Foot]

Originally Posted by TimmyB

That doesn't sound like the symptoms on mine. Air flow does not feel reduced/restricted; just not as cold after a while.

If you haven’t already - You need to insulate the dog-house over that engine.
I did mine and even after pulling long mountain passes, the doghouse is relatively cool to the touch.

[TimmyB]

Originally Posted by Big-Foot

If you haven’t already - You need to insulate the dog-house over that engine.
I did mine and even after pulling long mountain passes, the doghouse is relatively cool to the touch.

Yeah, I haven't done either of those mods yet. I've been a little hesitant to take off that doghouse cover, fearing not being able to put it back together!

[Big-Foot]

Originally Posted by TimmyB

Yeah, I haven't done either of those mods yet. I've been a little hesitant to take off that doghouse cover, fearing not being able to put it back together!

It’s really not difficult at all. A couple of the screws were tough to get the square-drive bit into, so I just taped the bit in the box end of a 1/4” wrench and walked them out 1/4 turn at a whack. I used 3/4” thick HVAC duct insulation foam and then DEI reflective fiberglass sheet over that. I used 3m #77 spray adhesive and HVAC Aluminum Tape on the edges.
I made a template first using rosin paper then cut it so it would lay flat.

[FstopMiami]

Originally Posted by TimmyB

I'm wondering if ours is suffering the same as ducksface's is. 36 sounds TOO cold and I wonder if it's icing up and that's causing an issue?

Low refrigerant, dirty evaporations coil, dirty air filters, all causes of lower than normal discharge temps as well as freezing of the coil.

Armando

[JohnnyD]

Originally Posted by ducksface

It's pretty easy to tell if it's the same as my problem.
Turn it on high fan and Coldest setting.
After a very consistent period of time, I think ours is about 35 minutes, the air will be cold, but it will be a bit dank and the air volume will be much much less.
Turn off the ac but leave the fan on
Air will still be cold, but will warm over a period of 8 or so minutes, and as it warms, air volume increases.
When the air is 60ish degrees(a finger feel) turn the ac back on by pushing the button.
It should all work fine for another time cycle.

We go through this many times a day. It has become second nature. I have, as a lay person, tracked it to an aftermarket valve Thor used, a kenworths part I think. I have the Info somewhere, no guarantee I'll find it and no guarantee it's the problem if I do find it for you... Becuae I'll likely never fix it. It just doesn't bother me to push that switch off and then back on after a while.

Hmmmm. Same problem here.

[Big-Foot]

When your AC is running, make sure the condensation in the evaporator can properly vent to the ground.
In other words, if it’s not dripping on the ground, the condensation will build up in the evaporator housing. Eventually, it will start to freeze up, stink and will ultimately corrode the fins etc...
There was a case I read of on one of these forums or on Facebook where the condensation was filling one of the fresh air hoses and was hanging way down from the weight of the water...

[JohnnyD]

Originally Posted by Lt Keefer

How was the outside temp on this trip compared to the last?

Was the humidity high on the second trip? I suspect the exchanger is freezing up at times.

[TimmyB]

Originally Posted by JohnnyD

Was the humidity high on the second trip? I suspect the exchanger is freezing up at times.

I can't quantify it, but it was definitely a muggier day, so I would think that it was higher on the second trip.

[Hugh.vines@att.net]

Originally Posted by TimmyB

Yeah, I was looking at them online last night. Have no idea what is "good enough".

Vent temp should be 20-25 degrees lower than outside. If you get that no problem. That’s straight from an ac repairman

[TimmyB]

Originally Posted by Hugh.vines@att.net

Vent temp should be 20-25 degrees lower than outside. If you get that no problem. That’s straight from an ac repairman

I've taken three readings so far. For all of them, I've let the engine run for five or so minutes, then recorded the temperature and the outside temp. For all three, the output was almost exactly the same at 39 degrees; outside temps were 72, 75, and 77 degrees. I won't know how it does with it running a long distance until we head out west in two weeks.

[ducksface]

Originally Posted by Hugh.vines@att.net

Vent temp should be 20-25 degrees lower than outside. If you get that no problem. That’s straight from an ac repairman

You need an ac guy that has worked on anything newer than 1963.

You're saying/he's saying that a 110 degree day produces an acceptable and prolonged 90 degree ac vent temp.


That seems like some bad information to me.