CX-5 AC Refrigerant Line Insulation?

[NCmazdaguy]

Hello!

New Mazda owner here. Picked up a CX5 this week, and am loving it so far (paint already chipped but we are moving past that). Drives great, build quality feels high, and I love how heavy the doors and hood are. I have read that the AC is not the strongest, and with the summer heat in full swing, this has already proved to be noticeable.

Got me wondering, what gives? I was poking around under the hood some, and noticed (what I believe to be) the refrigerant line. It's along the left side of the engine. It sweats like crazy when the AC is pumping. Every pipe and tube in the engine had some sort of insulation on it, with the glaring omission being the one pictured below. I asked the tech at the dealership about it, and he said 'it's not insulated because the insulation could trap some of the condensation, causing rust or corrosion.' That seems like a fair point, but surely there are work-arounds for it. The refrigerant lines in my home central air are insulated, why not these?

I don't think insulating this line would give a huge boost to the ACs efficiency, but couldn't hurt, right? Does anyone have any experience with this, or thoughts? Any HVAC techs here? Thank you!

 

[HyFlyer]

Firstly, welcome to the forums and congratulations on your CX5

... I don't think insulating this line would give a huge boost to the ACs efficiency, but couldn't hurt, right? ...

I'd say wrong. I'm no HVAC tech or anything but IIRC, after the refrigerant does it work inside the evaporator coil inside the car absorbing heat as it reverts from a compressed liquid back into a gas, that line you are picturing next to the engine is carrying that gas back to the compressor and condenser coil.

Insulating that line would make your compressor actually work harder.

I'm just going off of memory of general "how stuff works" knowledge built over a lifetime. So

 

[erhayes]

I insulated the COLD line in my CX5. I would like to think it helps but, no date to validate. Ed

 

[cz5gt]

when its very hot outside and also very hot in the engine bay (your home is not that hot as inside a running engine bay) it does that. Its normal. Leave it as is.
Its just condensation. It will evaporate on its own.

 

[NCmazdaguy]

Insulating that line would make your compressor actually work harder.

That checks out. Thanks for the input!

 

[sbs1963]

New CX-5 owner here as well, (2022 model year w/ just over 34k miles). First Mazda was a `79 RX7.

Not sure what year yours is but I've had mine out on the road in the 100+ heat (w/ humidity) here in NJ and the AC worked fantastic, actually had to disengage it at times bc I got too cold (I tend to run it with the inside air which allows the cool air to continue to circulate). It actually works better than my 2017 CR-V ever did.

I wouldn't insulate that line (as has been stated already) as the condensation needs to shed off which is normal for Car AC's and the reason there's a puddle under the vehicle when using the AC.

 

[RedBaron]

I wouldn't insulate that line (as has been stated already) as the condensation needs to shed off which is normal for Car AC's and the reason there's a puddle under the vehicle when using the AC.

Whether you want to insulate or not, *IF* you did insulate, there would not BE any condensation from that pipe, since the moisture-laden warm air would not be able to reach the cold pipe - thus, no condensation could/would form.

The puddle under the car comes from the outside air passing through the (cold) heat exchanger on the way into the car. There is a catch tray and drain system to pass the condensed water out and under the car.

 

[Jmaz]

If it ain't broke ..............

 

[Silly Wabbit]

If it ain't broke ..............

Improve it until it is!

 

[N7turbo]

Here is what I read on the subject the last time this came up.

AC and air box insulation

AC line insulation,Apparently NOT a good idea(edited after factual information was posted) see post 4 and 7 I was thinking about how hot it is under the hood and the placement of the AC coolant hose/pipe. I found a piece of insulation tubing, that is self taping at Lowes. It looks a lot like...

www.ssrfanatic.com

Do not insulate the A/C lines!
Especially the line from the evaporator (Dash) to the compressor inlet.
There's a reason why it's uninsulated.

The compressor compresses the vapor entering it from the evaporator core in the dash and discharges a high temperature/pressure liquid. The liquid loses heat in the condenser in front of the radiator. The refrigerant will pass through an expansion valve and into the evaporator. Pressure and temperature are lowered across the expansion valve and enters the evaporator in the dash which is what provides your cold A/C. Heat is absorbed by the refrigerant in the evaporator until it's fully vapor (if the system is properly working). At this point the compressor does it's thing again to compress the vapor refrigerant to start the cycle again.

Insulating the line between the evap and the compressor will NOT make things more efficient. If the suction temperature is lowered because of insulation, the discharge temperature will also be lowered. After the evap you WANT the refrigerant to lost heat to ambient so that what enters the compressor is fully vaporized. Liquid refrigerant entering the suction side of the compressor can damage the compressor. If the system is over charged or not cycling properly the evaporator can freeze up and the refrigerant can not absorb heat to vaporize the liquid sending liquid into the compressor suction and damaging it. The Compressor is made to compress gas only!

And this one:

Should I insulate air conditioner coolant pipes?
If you’re talking about refrigerant pipes, as in an air conditioning system, then the answer is it depends.
The suction line (the line that feels cold to the touch) is often insulated for two reasons:

1. To prevent condensation, as water condensing and dripping from the line could damage other things around it (such as wood or drywall in a building.)
2. To marginally increase system performance/efficiency. Insulated pipes will pick up less heat from outside the conditioned space so the system load will decrease.

And the reason against insulating:

You may want to pick up more heat in the suction line. This is to ensure all the refrigerant flowing through it has evaporated into gas before it reaches the compressor. Liquid is bad for compressors. Compressors are only meant to pump gas.

So, again the answer is it depends. It depends on the particulars of each system.

 

[Moonlighter]

Here in Australia (northern states like Queensland in particular) we get very hot and humid summers. This last December/January/February it was particularly hot and humid with most days over 35C and quite a few closer to 40C.

In the old imperial money, thats 95F and higher.

The AC systems in our current 2024 CX5 Akera G25 and our previous Akera 2.2D both handled this very well, never even a hint of struggling to keep us cool inside. We just set the temp at 22.5C and put it on auto, and away we go. Even in eco mode it easily does the job.

What AC settings are you using?

 

[AL Cx5]

I have been insulating the high, cold, side of my cars and trucks for years. This was one of the first things we did to our 24 CX5 T. My truck AC compressor lasted over 200K miles, all the other cars have the original compressors.

Insulation didn't make the air any colder. The air temp is controlled by a thermostat to prevent the evaporator from freezing.

What it does: the air cools down much faster and there is less load on the compressor. When the engine bay is hot, the AC has to cool down the high side line before the evaporator starts cooling. Insulated the high side speeds up cabin cooling.

Also, temperature gain in the high side from the engine bay puts more load on the AC compressor. The compressor has to work harder to cool, runs at a higher pressure and wears out faster. It uses more energy that may or maynot be measurable.

On my old R134A truck refrigerant, we changed out the refrigerant to a propane based refrigerant last summer. It uses 40% less refrigerant and the compressor runs at 40% LESS pressure. It cools like the old outlawed R12 of old. I ride around in +95 F temps with an ice cold cabin and a smile on my face. R12 of old was flammable too.

My research says if I replace the Mazda R1234 with propane it will use 50% less. For now, we are happy with how fast the car cools down and maintains the temp. If I have to replace a major component down the road and charge the system, I'll likely charge it with propane.

We folded a piece of reflective bubble material in half and placed it in the sunroof between the shade and the glass. This made a remarkable difference in comfort as well. Ceramic based window tint helps a lot and we have a strip across the top of the windshield.

Be COOL, be HAPPY!

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