I've noticed that the newer trucks aren't coming with insulation on the AC accumulator. Was this a cost cutting action or is the insulation insignificant when it comes to AC performance. I cant seem to find a definitive answer online, although I do know that the insulation traps moisture and leads to corrosion. My accumulator bracket is all rusted out and I'm replacing it and wondering if I should insulate the accumulator or not.

 

I would it's a fractional difference in cooling performance but in texas heat our hvac systems need all the help they can get.

 

I dont think it will make a difference since quite a bit of a/c lines are ran around the engine. I wouldnt worry about IMO

 

I can't answer the insulation question but I will recommend that you replace the bracket with something to secure the accumulator with the insulation or without. I was in the same boat ~2yrs ago, bracket was all rusty and insulation was falling apart. I removed the insulation and never got around to replacing the bracket. Now I have to pull the dash apart to replace the evaporator due to a leak that I attribute to the extra vibrations of not having the accumulator secure. However, in the time I ran the AC without the insulation on the accumulator, I did not notice a decrease in performance, although the accumulator would sweat pretty good.

 

Thank you for your input. That's very interesting about leak because I ripped everything off the accumulator and was going to run it without the bracket since the accumulator seems very secure without the bracket. Was yours loose in any way? Maybe the leak was just coincidence.

 

Put in a new accumulator and compressor in my 2000 silverado. The new accumulator unit was smaller than the old one. With the old one installed the ac was ice cold. The new one ...meh. Then I insulated the accumulator and line with butyl rubber tape and now the ac is ice cold again. Trial and error.

 

accumulator is after the evap. dozens of vehicles come without it wrapped. its not going to effect performance

 

I thought the insulation was to keep condensate from forming and dripping on something underneath the accumulator (starter?).

 

The AC system's job is to act as a conveyor belt for heat: to pick up heat from the (warm) passenger cabin in the air flowing over the evaporator coil, and transfer it to the (even warmer) ambient via the air flowing over the condenser coil. Literally, if you think about it, it's the thermodynamic equivalent of forcing water to flow uphill, except that it acts on heat instead of water. By consuming engine power, the system appears to violate the 0th law of thermodynamics, and makes heat move from a place of lower temp to one of higher temp, which isn't what heat ordinarily does.

That insulation prevents the system from picking up extra heat unintentionally, which then (a) increases the amount that must be "rejected" into the ambient, or (b) decreases the amount that can be absorbed from the cabin, or (c) both of the above.

The compressor is also cooled by "leftover coldness" in the refrigerant, after it has done its primary job.

The insulation retains that "coldness" against underhood heat.

I've always found insulating it to make a significant difference to both the system performance and to the compressor's apparent "happiness". I'd leave it if it's there, or add something if it's not, if at all possible.

My guess as to why it's not done, is "value engineering"... they must think it's cheeeeeeper to make up the difference that the insulation would make, in some other way that costs less. Or, that customers wouldn't notice the lower performance.