A/C performance

It’s 105°F and 20%RH, very sunny today.
I drive several hours in these temps, one day per week in the summer.
Since I’ve owned the 2020 Tundra (bought new) the a/c has been, “meh” - adequate, but never frosty. On hot days like this, it gets a bit uncomfortable.
I run it full cold, recirc, rear seats closed off, vents on face, not feet, windows all tinted. I’ve tried fan med, fan high.
I have white paper towels on the glareshield to reduce the heat reradiated there (not blocking the vents). The cabin air filter is new. Plenty of air flowing too. I always drive solo.
Laser thermometer shows 34°F at each vent.

I’m thinking the ac unit was undersized.

I’m writing this from my 03 Tundra - as an experiment I decided to swap vehicles and the 20 year old, which has never had the system looked at let alone cracked, is absolutely blasting me with delightful ice-air. I had to turn the fan down to med, it’s so cold. It’s showing 33°F at the vent.

Suggestions on the 2020 welcome.

 

Could you have a clogged up (bugs) or dented up (stones and bugs) condenser on the 2020? Just saw a guy add what I think is too large of an auxiliary tranny cooler that is likely going to reduce the effectiveness of his a/c refrigerant. Could be numerous things. Might even leak. I will say new refrigerant sucks for its intended purpose.

 

Why not open the rear seat vents to allow the rear to be cooled vs depending on the front to cool the back and the back to basically heat the front. Just let it function as designed. You might have better luck.

 

Sounds like it’s working as well as one could expect. I’m amazed to hear you’re getting air in the low 30s out considering that would have to make the evaporator itself even colder than that. If the evaporator itself is below 32 degrees the condensate freezes to the coil and turns it into a block of ice. I would recommend some ceramic tint on the windows which keeps the sun’s rays from heating up the cabin so rapidly.

 

My Tundra is black but a double cab. I usually run ác vent and floor mixed. All vents open and recirculating. Usually cools down good. After a while it gets too cold to where I have to turn it down. You’re probably better off keeping all the vents open. More places for cool air to come out should be a good thing.

 

The evaporator might actually be getting iced up partially and blocking some airflow. Is water steadily dripping under the truck?

 

Thanks for your thoughts
I carry a bunch of crap for work in the back seats and the vents are largely blocked; could fix that.

Why would the vents be closeable, if it’s ‘designed’ to work with them open?

 

I really don’t think it’s freezing, it’s making 34°F air (I think I trust the thermometer, both trucks measure similarly) and the 2020 feels the same from the time I start up (ie, not frozen) till a half hour or more later.

Anytime else had their 2020 out in 100+ temps?

 

Passenger comfort levels vary between a group. The ability to adjust airflow provides options for said passengers. I guarantee you if on a hot day I were to close 30% of the vents in my house, it would become uncomfortable relatively quickly.

 

That's so interesting.
I close off the vents in two rooms of my house in the summer because no one is back there, and this forces all the cold air goes into our living space - the a/c runs a lot less and it cools faster than if they were open. <shrug>
However, maybe the truck is different. I'll give it a try. Thanks.

 

34 degree from each vent...How much better than that are you hoping for? Below 30 degree? I believe the standard temperature from the vent is no higher than 40 degree. Your ac is working well.

 

Well, you'd think it is...but it is not.
Definite difference between the old truck and the new one. Despite what the thermometer is reading at the vent.
It's a long thread, lots of info. Wondering if you missed the details.

 

No details needed. Your A/C is blowing 34 degree from each vent with good air flow from each vent...you can not expect your AC to do better than that. Only thing I can think of is your older truck is better insulated than your 2020 truck. But not AC fault.

 

One explanation would be is that the unit is not generating enough btus for the heat entering the cabin.

Think of what you are saying with this analogy in mind, friend.
You have a household window unit blowing icy cold air in large volumes… into an empty building the size of Walmart. Ain’t never gonna get that room cold! Too much heat for a 5000 btu window unit.

I posited that the truck unit might be inadequate for the heat it was being asked to counter.
Others suggested opening vents fully, and I’ll try that.

I did have data on interior temps (cabin surfaces) but need to repeat that.

I’d really like to hear from someone who drives in Cali/Arizona in the summer.

 

Houston ship channel.

Africa hot. big humidity

A/C does fine. I do have ceramic tint. and use a fitted sunscreen when parked.

bi-level setting produces more air....cools better. less cavitation/turbulence - more air over the evap.

 

You mentioned on your first post..."plenty of air flowing" and the air vents is blowing 34 degree. How is this a BTU problem with your AC ? Are you trying to say there is NOT enough air flow at 34 degree? Because 34 degree is damn good.

 

I think our trucks are very poorly insulated, especially in the roof area.
I have a black 2020 crewmax. If my truck is parked in the sun a few hours and I pull my sunglasses out of the overhead compartment... they are almost too hot to touch.

I have super dark tint on all windows except the windshield and it helps a little... but overall I think the AC is undersized and the truck lacks alot of much needed insulation.

 

When setting up a furnace, fan speed is set in conjunction with heat rise but for AC, fan speed is usually maxed out. With that being said, one thing I noticed about my wife’s newer Lexus and my 2017 Tundra is that the max fan speed is pretty lame compared to my older Toyotas. While it won’t affect the temperature any, 30 something degree air blowing on your body at mach 3 speed will definitely feel colder than the wimpy fan in these Tundras. Just like a wind chill calculation. The fan in these trucks suck!!!

 

My tundra’s AC is weak compared to my previous black Silverado. It eventually gets the cab cold but it takes a long time and the truck has to be moving. And yes I’ve got ceramic tint on all windows and the windshield. The insulation thing makes sense as the cab of my tundra is also a lot louder than what my Silverado was. Yesterday was the first time I’ve driven it in triple digit heat (central Texas) and I was surprised by the weak AC since I’ve always thought it was pretty dang good. Might do what I did to my old mega cab and put some reflective barrier about the head liner to help with the heat.

 

This is what I’ve always done and it works better than just running the front.

 

Good info, nit.
I’ll keep working on it.
Thanks

 

“Aha”
Thanks Centex.

 

2020;
34° is good
Airflow subjectively, is good.
So, a person gets to wondering why the truck is hot inside, right?
Compared to the 20yo Tundra.
The btu produced vs being carried away is a theory. ONLY a theory.

 

maybe....it's the lack of humidity you have.

not quite sure my premise is sound....but it appears to be the only variable that differs.

 

But we still have the discrepancy between the two Tundra. The ‘old’ Tundra frosted me yesterday, in the 108° heat, it’s cooling the cabin great.
I do appreciate the productive ideas however; thank you - let’s keep thinkin about it.
I’ll keep doing changes, see if it can be improved.

 

I had 2 first gens, and it’s definitely a significantly smaller cab to heat and cool. Humidity wise, the performance would be better the drier the air is. Less cooling capacity has to go toward removing latent heat for moisture removal and more capacity can be used for sensible heat removal.

 

In high 90s my 2019 DC is barely able to cool the cabin down enough to stop me sweating. I'm getting a Weathertech sunshade set.

I think it's about insufficient tinting. I've wrapped my old Volvo into ceramic tint and it was cool like never before. Once totaled, I've got a donor car to transplant my good drivetrain and interior. The A/C was struggling a lot in summer, because the car was not tinted. Tinted myself with a very expensive FormulaOne Stratos, the interior is not getting very hot to begin with, so the A/C is working maybe at 50% if not less.

 

If all else fails lose your shirt before climbing in! Back in my youth, shirtless, wing windows, rear slider, and a heavy foot were the only options. I learned pretty quick get things done in the morning or night and sleep from noon to six. Maybe you can try that as well

 

34°F at the vent is amazingly cold. How does that not freeze over the evaporator whenever humidity goes up?

In the name of mpg my old Honda was set up from the factory for compressor off at 45°F and on again at 55°F. Now that was a terrible AC system.

 

If the two trucks are only 1 degree different then the only other factors would be air speed from vents and size of space needing to be cooled. If both fans are blowing at relatively the same force (air speed) then the only other thing I can imagine is that the size of the cabin on the '20 is causing it to feel warmer because there's more space to cool down. Let alone the rear vents being closed and hot air just sitting in the back part of the cab.