What’s the best recipe for igloo A/C units

AggieMike88

AggieMike88

Touchdown! Greaser!
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The original "I don't know it all" of aviation.
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For those using igloo cooler a/c units in their airplanes, what is your secret recipe of “fuel” (ice and water) to get the longest lasting stream of cold air?

block ice? Cube ice? How much water? Brine?
 
Brine would corrode the thermal exchanger. Block ice with a bit of water.
 
Someone told me to put frozen 1 ltr water bottles with enough other water to cover the workings.

The bottles will keep the cold, and when you land still be nice for drinking.

Not sure if that's a round-trip idea.

YMMV
 
I use 7 of those reusable blue cooler thingies with separators glued to the sides of the cooler for even air flow. Doesn't feel like a car but it knocks the heat down to bearable at least.
 
Doc Holliday said:
We’re in the golden age of aviation......

What’s with this igloo ice cooler AC stuff? ;)
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Doc, sometimes it's difficult to tell if you're pulling me leg, or you're so busy under your rock you missed a memo or three....

I'm talking about devices similar to these: https://www.b-kool.net

986940.png
 
I use b-cool. the dissipation of cooling effect is proportional to surface area of the ice. Little cubes of ice filled in that cooler will melt a lot faster. The block has a lot less exposed surface area. Hence it lasts a ton longer. I have a place about 10 min away that sells block ice through a coin-op machine. Absolutely awesome- makes it easy to get as opposed to heading to the ice plant.
 
From the Piper list:
Using frozen bottles, the coldest water remains trapped inside the bottle adjacent to the ice core and never gets circulated. There's a temperature gradient from that ice core to the bottle surface. The freely-circulating water (that goes through the heat exchanger) can never get colder than the surface of the bottles, which will always be warmer than 32F once the ice starts to melt. (The heat transfer also becomes less effective as you increase the separation between that inner ice core and the water circulating outside the bottle...the heat has to pass through the buffer of the stagnant water inside the bottle. You end up with heat in the circulating water that has a hard time transferring to the remaining ice in the middle of the water bottle.)

If you use ice cubes instead, the freely-circulating water is always in contact with 32F ice. That's the best-case condition to transfer heat from the circulating water into the ice.

Using different sizes of ice cubes/blocks will also achieve different performance:
- Crushed ice has max surface area exposed to water, meaning it will absorb heat most readily. Outlet air temps will be coldest possible and remain at a pretty constant cold temp, but cooling duration will be shortest and once all the ice is melted, outlet temps will spike quickly to ambient temps.
- as ice cube/block size increases, the surface area exposed to water decreases. General effect is that the larger the ice cubes, the longer you get some cooling effect, and the more gradually the outlet temp will rise to ambient.
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Summary - big-ish block ice. I use a mix of ice cubes from my freezer at home and a bag of crushed ice from the grocery store. Crushed ice goes on the bottom to protect the pump. I use a quart of water. I tried the large frozen bottles of water - didn't work that well. Went back to the ice. I put one of the bottles in the cooler so that I have cold water to drink.
 
Why the question Mike? It’s not hot where you are is it?:eek: Friday morning 10AM, it was 25C at 6,500. I was finished and on the ground shortly thereafter and was glad to get out. Can’t imagine what it would have been like a few hours later. I fly again at 7AM tomorrow and expect the same or worse before we’re done.
 
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MBDiagMan said:
Why the question Mike? It’s not hot where you are is it?:eek: Friday morning 10AM, it was 25C at 6,500. I was finished and on the ground shortly thereafter and was glad to get out. Can’t imagine what it would have been like a few ours later. I fly again at 7AM tomorrow and expect the same or worse before we’re done.
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I’m dreading August. If it’s this hot in mid-July, it’s not gonna be much fun 30-45 days from now.
 
I expect we might as well get ready for at least 60 days of this. If my Instrument written weren’t expiring August 31 I would limit my flying to off the ground at 6 and down by 8. I’m really getting to be allergic to the heat in my old age.
 
A few weeks ago I bought a Glacier Tek sports vest. I've only had the chance to use it twice so far (once flying and once while mowing the yard), but I don't regret the purchase so far.

The pre-flight lasted about 30 minutes in 94 degree temps with a heat index of 108. I was definitely sweating while fueling up the plane, but I sure felt more comfortable than I would have without the vest on. By the time I got back in my car I guess I had worn it for an hour and a half and it was about 80% or 90% melted, but I thought it was still worth wearing even as I was putting the plane back in the hangar.

It's a little bulky (it could be mistaken for a bullet-proof vest, which perhaps isn't ideal) and expensive, but for me it's better than the ice-chest options because I can wear it while I pre-flight the plane. It also keeps me from having to make a stop on the way to the airport to pick up ice and lastly, it saves the luggage area for actual luggage.

I would say that it didn't get in the way at all during the pre-flight activities, but it wasn't comfortable to wear while seated in the plane because it pushed me forward in the seat, although I could probably remove one or both of the slide in units that go on the back area and that would resolve that problem. The slimmer flex vest that they have might be more comfortable to wear while seated, not sure.
 
That vest looks cool. Because I reserve the right to complain about winter cold I never complain about summer heat.
 
I don't use it anymore because it was just too much work for what I got out of it. However when I did, I liked making huge ice blocks ahead of time. Large plastic bottles, such as milk jugs or other half gallon-gallon with the tops cut off work well. I also had some success using silicone cupcake trays for big ice. You definitely want big pieces- small ones melt rapidly. OTOH if it's not getting good thermal contact with the water it's not cooling it.

It's easier to dress in moisture wicking clothing that will dry fast and just deal with the heat for the few minutes you'll be on the ramp and taxiway.
 
Someone on here should be smart enough to 3D print a mini airplane compressor that can make air conditioning very light and extremely efficient. You guys are smart I've seen you answer questions.
 
Planning a beach trip soon, also planning on a 6:30am departure at the latest. Fly while it's cool and smooth!
 
The Arctic Air seems like a decent compromise solution, but I'd sure hate to give up the baggage space. It's also 42lbs in my CG sensitive plane, not to mention that the power draw and actual utility of it concern me a bit since I'd need the 14v model, limiting the BTUs I believe. I've heard it can work pretty well if you install it properly though. I think there have been a few iterations of the installation and the current procedure resolved some original shortcomings. The alternative, at least for the Bonanza, is the FTA system, which would save my baggage area and be nice and clean, but it's also $25,000.
 
Personally, $300 and needing to find ice definitely offsets the $4k price! I’ve looked at the Arctic Air at OSH and wasn’t impressed $4k worth.
 
Ok, I've resisted, but no more. I can't be the only one thinking the best recipe for cooling is water + freezing temperatures, right? ;)

Surface area is important. Would an ice block with vanes on it be a better choice? Need a form to freeze the block in.
 
bflynn said:
Ok, I've resisted, but no more. I can't be the only one thinking the best recipe for cooling is water + freezing temperatures, right? ;)

Surface area is important. Would an ice block with vanes on it be a better choice? Need a form to freeze the block in.
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Liquid N2 - fo sho!
 
Challenged said:
The Arctic Air seems like a decent compromise solution, but I'd sure hate to give up the baggage space. It's also 42lbs in my CG sensitive plane, not to mention that the power draw and actual utility of it concern me a bit since I'd need the 14v model, limiting the BTUs I believe. I've heard it can work pretty well if you install it properly though. I think there have been a few iterations of the installation and the current procedure resolved some original shortcomings. The alternative, at least for the Bonanza, is the FTA system, which would save my baggage area and be nice and clean, but it's also $25,000.
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50lbs of aft CG helps the 310 balance out well since it has that massive weight installed on the yoke. Literally, it does.

If the flight controls aren’t rigged correctly, it takes 2 arms to land the 310.

I like that the ArcticAir is removable giving me the 50lbs back when the temp is low.

I used the ice cooler in Houston and it’s just too hot for it. It works for about 2 hours and that about it. The good thing about the cooler was being able to pre-cool the cabin and use it on taxi out. I hoping the air conditioner will hold up to expectations. $4k seems a lot better than $25k. With install it’s closer to $6k.


Sent from my iPhone using Tapatalk
 
Does quality if the chill chest affect the equation? Aka, if the chest was a converted Yeti cooler, would you get any longer run time?
 
SixPapaCharlie said:
Someone on here should be smart enough to 3D print a mini airplane compressor that can make air conditioning very light and extremely efficient. You guys are smart I've seen you answer questions.
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The biggest issue is where to dump the heat. Don't know all the rules, but you'd need a fairly large opening (easier) or openings (more efficient) outside the plane. Reading about the ArticAir...you need to cut holes. Troublesome. Seems the problems aren't really about the mechanicals, but about packaging and plane modification.
 
Well, if the back wall into the tailcone isn't structural, you could cut a hole in that dump the heat into the tail cone.
 
EdFred said:
Well, if the back wall into the tailcone isn't structural, you could cut a hole in that dump the heat into the tail cone.
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Would the tailcone itself have sufficient outflow? Other issue would be that you'd have to take cooling air from the cabin to do that, which means cooling with conditioned air. That would severely impact efficiency. (Compare one and two hose efficiency for wheeled room A/C units.) Since it's all electric and you're limited by alternator output, any hit to efficiency is a hit to total cooling capacity. Avionics in the tailcone may also be unhappy with the rise in temps.

I know this is how it's done. And it works. Just doesn't seem like it would pump enough to really work in the sorts of climates that this would be most useful in. Haven't done the math directly, though, so these are mostly SWAGs.
 
AggieMike88 said:
@Fracpilot ... what is involved with install?
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1. There’s a control head like a thermostat to be mounted.
2. There has to be a 60amp CB installed.
3. There’s wiring from the control head to the CB.
4. There’s wiring from the circuit breaker to the plug that is inserted into the unit.
5. There’s an optional drain line for water. It also collects in a tray to be emptied at the end of the flight.
6. There’s a required exhaust hose to be vented in the tail section or outside of the airplane.


Sent from my iPhone using Tapatalk
 
AggieMike88 said:
Does quality if the chill chest affect the equation? Aka, if the chest was a converted Yeti cooler, would you get any longer run time?
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Definitely. Better & more insulation means the ice lasts longer. I have a cheap igloo that I use when defrosting the big freezer in the basement - walls are about an inch thick, if that. Walls on the Icobox and the B-Kool are considerably thicker. Wish I could find the link again....someone took a regular cooler, lined it with building insulation and said it kept everything cold all day in the hot car. The regular white foam doesn't work because it's permeable to air and doesn't work well with the ice & water (ice tends to crumble the foam, which causes problems with the pump). He used something like this:

https://www.homedepot.com/p/Owens-C...ared-Edge-Insulation-Sheathing-52DD/202085962

but with aluminum on one side.

A cheaper and faster option is to line the cooler with aluminum bubble wrap stuff - like the incredibly expensive Kennon sun shields - but you can buy it in rolls at the big-box hardware stores.

https://www.homedepot.com/p/Reflect...MERCH=REC-_-searchViewed-_-NA-_-100012574-_-N

and cut to fit.
 
AggieMike88 said:
I’m dreading August. If it’s this hot in mid-July, it’s not gonna be much fun 30-45 days from now.
Click to expand...

For sure. I've been putting some thought to building one of these as well for the coming months. Going to be a hot one down here on the Gulf coast.
 
So we are just starting to explore using a portable AC unit in our Grumman Traveler but we have some questions. We are thinking of an ice type system like the ones mentioned above. I am assuming that the the heat in the cabin is transferred to the ice to melt it and raise the temparture of the ice water eventually. But is there any heat released back into the cabin? The second question is about the moisture; is there moisture released in the cabin from ice water? I am worried about creating an environment that will cause corrosion issues with either the plane or the avionics.
 
I use a B-Kool in my Bonanza. It really takes the edge off the heat and works best for the two people the cold air vent is closest to. I think your Traveler is a bit less cabin area, so the benefit should be even greater.

You are correct that it basically converts the hot air to melted ice. There is no heat created by the unit. Even if all the ice melts, you end up with a cooler full of water and that water can hold a lot of heat. It won't ever be hotter than the surrounding air.

I don't have any problems with moisture being released into the cabin. The only way that might happen is if you use cubed ice and it's piled so high that the exhaust fan on the lid of the cooler is chipping away at it (you'll notice right away that it's hard to close the lid).

It's best to use block ice so that there is less surface area and the ice lasts longer. I get between 40 minutes and an hour of use out of it. If you are plugging it into a cigarette lighter that isn't close to the pilot's seat, then it's good to have a remote switch. You really need it for the first and last stages of your flight. Once you're at altitude, avoid the temptation to keep it running and save your ice for when you will need it.
 
I feel for you all down south living in the heat. I spent 1 1/2 years living in northern NV and remember those sauna like flights. Don't have that problem anymore living in SE AK.

METAR PAJN 031353Z 08004KT 6SM -RA BR SCT004 BKN029
OVC038 13/12 A2991 RMK AO2 SLP130 P0012 T01280122 $=
 
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