Review of Yeti portable A/C unit

[EricJ]

1 hour ago, Pinecone said:

The ice coolers will not cool the entire cockpit, but a nice stream of moving cooler air does a lot for comfort.

Yeah, that's all you need.    It works fine for me when it's 115F+ here and it lasts quite a long time.    It just needs to cool a bit of air blowing on you long enough to get off the ground (which can definitely be longer than ten or fifteen minutes here), and then descending back below 4-5000 ft when it's really hot, so maybe another ten or fifteen minutes to get you back on the ground and taxi to park.    I've done multiple cycles of that on one ice/pack charge in the B-Kool without issue.   I think I ran it flat once in the five or six years I've had it.

 

[EricJ]

1 hour ago, 1980Mooney said:

Once the ice melts it is done. 

Once the water temp, actually the entire contents of the B-Kool, including freezer packs or whatever, equals the ambient air temp it is done.  

[Pinecone]

I wonder if you could use a thermoelectric cooler to "recharge" the unit in flight.

[Skates97]

3 hours ago, Pinecone said:

The ice coolers will not cool the entire cockpit, but a nice stream of moving cooler air does a lot for comfort.

Exactly, it doesn't need to cool down the whole cabin. A stream of cool air blowing on the back of your neck and head does wonders for comfort. Seeing the prices of those things makes me love my homemade one even more. Add the static cling tint to your rear windows to help with the heat. Then take a few spare squares of the static cling, fold them up, and keep them in your seat back. You can pull them out and put them wherever you want on the front windows and up high on the windscreen in flight to block sun. When you need to just peel them back off in descent. If you put them on top of the dash for a couple minutes they become soft and easy to smooth out on the windows.

Homemade AC

DIY Window Tinting

[Hank]

2 hours ago, KSMooniac said:

Best use case in my experience is ground ops and initial climb only.  I adjust the vent tube to blow at the back of my head/neck, or between my wife and I, and it helps tremendously with comfort.  It cannot be left on all flight long as explained above, so we turn it off after climbing into non-scorching air, and back on during the descent.  The B-Kool remote makes this easy since mine is plugged in at the back of the plane.  

This may be the selling point for the Yeti instead of the generic version. Yeti has a well-deserved reputation for keeping cold stuff cold, so maybe there will be more left to use at the end of your flight? Me, I just sweat it out . . . .

[A64Pilot]

1 hour ago, Pinecone said:

I wonder if you could use a thermoelectric cooler to "recharge" the unit in flight.

If you mean Peltier plate, No. They are terribly inefficient and actually provide very little cooling or heat. If you put cold drinks in a peltier plate cooler it will keep them about 50F, if they are warm, forget it. I had a Coleman when I was Road Racing motorcycles, piece of junk, old fashioned ice chest was FAR superior.

This says a Peltier plate is about 5% efficient, a decent heat pump is at least 300% efficient, an AC is a heat pump. https://rimstar.org/science_electronics_projects/peltier_effect_module_cooling_efficiency_test.htm#:~:text=Peltier modules are only around 5% efficient.

Anything that could re-charge could cool directly.

There are pretty much only a few options, either running a compressor for vapor cycle cooling or if you have a turbine an air cycle system works really well. Or absorbing heat by having a cold mass, and water conveniently is about the best substance there is.

If your really hard core a water vest can seriously keep you cold for quite a long time, but that’s pretty hard core for pleasure flying https://www.summitracing.com/parts/shf-1052-2022?seid=srese1&ppckw=pmax-safety-equipment&gclid=CjwKCAjwwb6lBhBJEiwAbuVUSkhuAhKDX4SAcmGirtln6Ccx-RWwgeIkApY8nYHcitKRd9gZ0p-neRoCxhsQAvD_BwE.

I think you could build a better system for not much money, but it would take a bigger cooler to hold more ice which of course means even more weight, because you can’t increase efficiency by much at all. Just use a bigger hammer

[A64Pilot]

2 minutes ago, Hank said:

This may be the selling point for the Yeti instead of the generic version. Yeti has a well-deserved reputation for keeping cold stuff cold, so maybe there will be more left to use at the end of your flight? Me, I just sweat it out . . . .

If you figure average flight is only a couple of hours then the difference in heat gain from an inexpensive cooler and a Yetti is minuscule. Your just paying for the brand name.

[Justin Schmidt]

I use an Icybreeze and not just in my plane. It has a liquid heat exchanger. Put some water in the cooler with ice. Has a battery and can be used with a 12 car plug. Also has a remote (wired) so you can turn it off/on in flight (I put it in the baggage area). Doesn't have the humidity issue that swamp coolers do.

[firelog1101]

Different heat in the southwest but opening the overhead cabin vent, window vent, eyeball vents near the legs, and the underleg vent usually works well enough. Point the eyeball vent through your shorts keeps things cooler...

Get the engine going asap. Make sure people are wearing appropriate clothing for the heat. That's loose fitting t shirt and shorts with airflow. 

Only other thing that could really help is some kind of AC unit hooked through the side window to provide Prestartup cooling.  Too much hassle for me...

[bcg]

22 hours ago, KSMooniac said:

I have a B-Kool unit in a "regular" cooler and find it helps tremendously in the summer.  Mine has a bluetooth remote on/off that is very handy since I typically load it as far back in the plane as I can.  To get the longest duration of cooling, I freeze big blocks of ice and use those vs. a typical bag of cubes.  Away from home, grabbing a bag of ice on the way to the plane or at the FBO is still quite helpful, of course.  I also limit operation (generally) to ground ops and initial climb, and maybe final descent as it won't cool for hours.  It is certainly better than nothing, and you can remove it when not needed if you need more space or useful load.

I saw the Yeti version a year or two ago and kinda chuckled... the performance of a Yeti cooler is kinda wasted in this application since you're pulling ambient air into the thing, so I'm not sure it is any better than my B-Kool unit with a pre-Yeti body.  (For the record, I am a Yeti fan and will bring my small cooler to OSH!)

 

Same, I've got a B Kool and use block ice or frozen water bottles where I can.  I don't have the remote, I plug it into my cigarette lighter and use a little switch on that plug.  Using a Yeti cooler for this is dumb, you're not going to keep ice for a long time using it, the purpose of it is to thaw the ice and remove heat from the plane.  We've used ours landing in 105 and it kept it comfortable in the plane.   Last week I flew my wife from Kerrrille to Corpus Christi and back and she didn't complain at all about the heat.  We had to stay low because of some cloud layers so we needed it for almost the entire trip.  Her not complaining about being hot is about the highest praise this thing could get.  It's an absolute game changer for summer flying.

 

I also put the static cling window tint on my 4 side windows and that helped tremendously without negatively effecting visibility.  I'd actually say I can see better now without the glare from the sun.

 

***EDIT TO ADD*** I like frozen water bottles or freezer packs in it best with just enough ice to circulate water because this provides cool air for the longest possible time.  Regular or crushed ice will give you colder air but for a much shorter period of time and that's not really helpful for me.  My plane lives on a tie down in Kerrville while I wait on a hangar, it's 104 as I type this so our summers are hot.  I keep a Bruce's cover on the plane and that helps a lot in keeping the inside cooler.  The tinted windows made a noticeable difference as well.  I usually start early in the day but if it's in the mid 90's already and I do the exterior preflight before I take the cover off and get the engine running and the B Kool blowing, I can keep it cool enough that we're not sweating until I get to altitude.  You've got to close all the exterior vents though, any hot air coming in from outside will compete with and usually overcome the cooler.  Once we climb to about 65, I'll open my vents and at 55 - 60, I'll shut the cooler off.  On descent, I close the vents and turn the cooler on at about 70 and it gets us onto the ground and to the terminal or tie downs.  It's not an AC but, it is enough to make the hottest parts of the flight much more comfortable.

[exM20K]

8 hours ago, 1980Mooney said:

You are missing the limitation of the thermodynamics.  In this case the Yeti is NOT designed to " hold the cold longer" - it is designed to melt the ice, circulate water through a heat exchanging coil and blow cabin air through the coil.  The only and total heat transfer is from the melting ice.  Whether it melts, transferring cabin heat through the sides of the ice box or through the heat exchanger is irrelevant - it cools the cabin to a limited degree.  

The Yeti will not last longer.  Both advertise that they hold the same 20 lbs of ice.  Once the ice melts it is done.  It is the 20 lbs of ice melting in both boxes the provides the total cooling BTU's

• The B-Kool and the Yeti both hold 20 lbs of ice. (also noted on web site)
• One (1) pound of ice absorbs 144 BTU's when it melts (latent heat of fusion)
• Both the B-Kool and the Yeti will provide 2,880 BTU's in total cooling from melting all the ice 
• You can probably get another 200 BTU's of cooling as the fully melted water rises from 32 degrees to 42 degrees F.
• So fully exhausted a B-Kool and Yeti both provide a whopping 3,000 BTU's cooling in total
• A typical small car air conditioner will provide 12,000-18,000 BTU/Hr cooling.  A large car air conditioner provides 24,000-40,000 BTU/Hr cooling

So both the B-Kool and Yeti in total will provide the equivalent of what a small car A/C can to in 10-15 minutes on high.  If you are taxiing and holding for 10 minutes on a blistering Texas Gulf Coast day,both the Yeti and the B-Kool will largely be spent.  Then the water in the chest will start to warm up and instead of condensing on the coils, it will act as a humidifier if you keep it running.

The Kelly Aerospace built-in unit for the Mooney is 11,500 Btu/hr, so your math seems about right.

I use the B-Kool mostly on the ground and approach/landing, say 12 minutes (0.2 hr per flight).  It is maybe half or 2/3  exhausted after that (using cubes), so 2000 btu's per .2 hour or  10,000/hr though you can't sustain it for an hour.

Used for taxi, approach, landing and taxi, it is putting out approximately the same cooling as the Kelly unit, just with limited duration.  I'd still consider the Kelly unit if I could get the lithium battery people's attention for an STC.

I have an evaporative vest for use on a motorcycle, which is similar but worse.  Once the water is fully evaporated, I have a nice, warm vest around my core!

-dan

 

[EricJ]

10 hours ago, Pinecone said:

I wonder if you could use a thermoelectric cooler to "recharge" the unit in flight.

Peltier coolers are really only good to provide a cold surface if you really need a cold surface somewhere.   The other side of the Peltier cooler surface will be VERY HOT and unless you can get rid of that heat somewhere other than the cabin it'd be counter-productive.   They also use large amounts of electric current. 

[1980Mooney]

12 hours ago, EricJ said:

Once the water temp, actually the entire contents of the B-Kool, including freezer packs or whatever, equals the ambient air temp it is done.  

Actually I never let it go that far. As the water gets closer to ambient temperature, heat transfer rate plummets and all it basically does is dump highly saturated humid air into the cabin. I get it that you are in Arizona and you want humidity but in Houston it sucks. The last thing I want is more humidity at ambient temperature. 

[EricJ]

1 minute ago, 1980Mooney said:

Actually I never let it go that far. As the water gets closer to ambient temperature, heat transfer rate plummets and all it basically does is dump highly saturated humid air into the cabin. I get it that you are in Arizona and you want humidity but in Houston it sucks. The last thing I want is more humidity at ambient temperature. 

With no evaporation there's no humidity increase.   There's not a lot of evaporation in these, and even less as the temps equalize.   It'd cool better if it was evaporating, because evaporation absorbs heat and puts out cool air.   Evaporative coolers use up a lot of water.    These don't so much.  

[1980Mooney]

2 minutes ago, EricJ said:

With no evaporation there's no humidity increase.   There's not a lot of evaporation in these, and even less as the temps equalize.   It'd cool better if it was evaporating, because evaporation absorbs heat and puts out cool air.   Evaporative coolers use up a lot of water.    These don't so much.  

“With no evaporation there's no humidity increase.”  ….The only time that there is no evaporation is when you are at 100% humidity.  At that point it is literally raining inside your plane or car  

I grew up in the arid southwest. I understand the benefits and limitations of evaporative cooling.  We used to hang a canvas water bag on the hood ornament of our car when driving. - both for cool water and to provide some cooler air across the radiator  

You don’t see evaporative cooling on any house in Houston because all it does is make you feel more miserable. 

[EricJ]

1 minute ago, 1980Mooney said:

You don’t see evaporative cooling on any house in Houston because all it does is make you feel more miserable. 

Evaporative coolers often don't work well in Phoenix during our monsoon season for the same reason.

Fortunately, the B-Kool type coolers aren't evaporative, so they still work.

[1980Mooney]

1 minute ago, EricJ said:

Evaporative coolers often don't work well in Phoenix during our monsoon season for the same reason.

Fortunately, the B-Kool type coolers aren't evaporative, so they still work.

When you let the water warm up to ambient, B-Kool type coolers (which suck air through the inside of what is at that point just a box of water) become evaporative. 

That is why I shut it off before that point.  

[EricJ]

5 minutes ago, 1980Mooney said:

When you let the water warm up to ambient, B-Kool type coolers (which suck air through the inside of what is at that point just a box of water) become evaporative. 

That is why I shut it off before that point.  

If there's evaporation happening, it'll be cooling the air.

[1980Mooney]

25 minutes ago, EricJ said:

If there's evaporation happening, it'll be cooling the air.

It does to a limited degree. But the humidity is so high that “the humans” feel terrible.

You said evaporative air conditioning doesn’t work during your “monsoon season”.  I think if you measure the temperature across the cooler you will find that it still is cooling. The difference is not as much cooling as when using dry air - and the biggest difference is that the relative humidity becomes so high that it “feels bad - miserable”. You characterized that as “not working “ ….Just like running a B-Kool with ambient water in the box. 
 

 

Edited July 14, 2023 by 1980Mooney

[Hank]

6 hours ago, EricJ said:

Evaporative coolers often don't work well in Phoenix during our monsoon season for the same reason.

I've been to El Paso during monsoon season. The nice checkin person at the hotel was complaining about the "high humidity"--it was 15%! Here in Sweet Home,  we don't even get that low during winter cold snaps! We're excited in the summer when humidity drops to 60%. 

So I sweat out taxi, departure and approach, and cruise as high as possible. Even 6500 feels much better . . . .

Today will be a high temp of only 90, but there are Heat Warnings out because the Heat Index will be 106. Evaporative cooling just doesn't work. 

[FlyboyKC]

20 hours ago, Justin Schmidt said:

I use an Icybreeze and not just in my plane. It has a liquid heat exchanger. Put some water in the cooler with ice. Has a battery and can be used with a 12 car plug. Also has a remote (wired) so you can turn it off/on in flight (I put it in the baggage area). Doesn't have the humidity issue that swamp coolers do.

I use  the Icybreeze as well. I have the two tube extensions, one side for me and one for the Miss's which she really likes, and it keeps the complaint level down... 

[kris_adams]

Happy B-Kool customer here.  I got the remote option which I use on most flights.  I'll be changing to block ice once I get a freezer in my hangar.  It gives plenty of cool to get to altitude.  We have a lot of yeti, but I don't think I'd splurge.  Plus the lack of a hose to pump out the water is a big minus (unless I missed it).  I use that almost every time.

[bcg]

Used my B Kool today for a ERV - RBD - ERV trip it was 95° when we got to RBD, 102° when we left and 100° at ERV. The little cooler kept us comfortable through all the ground ops and climb, even when they kept us low through the Bravo. Seriously, I wouldn't fly in summer without it now.

Sent from my Pixel 6a using Tapatalk

[A64Pilot]

Instead of block ice which fills the cooler with water that has to be emptied, try freezing a couple of milk jugs. Yes there has to be some water in the cooler to work of course but when the milk jugs melt they keep the water in the jug, so you don’t have to drain the cooler, just take the jugs out and put them back in the freezer for next time, even if you carry them home if transported in a cheap styrofoam cooler there won’t be much melt at all.

In the boat my Fridge / freezer had “cold plates” two big stainless steel plates filled with Eutetic fluid, theory was you used Solar power generated from panels to freeze these plates and the compressor didn’t run at night and the cold plates kept things frozen over night, it worked very well.

It’s usually salt and water but mine had water and diluted anti-freeze. What made it “better” than plain water was it was way colder. 

A very dilute solution of RV antifreeze and water that froze say at close to 0 degrees in the jugs and the cooler ought to supercharge the B cool, most freezers can easily go to just below 0 pretty easy. RV antifreeze as it’s not poisonous but regular car antifreeze is, beside RV antifreeze is cheap.