While number four for takeoff on a 95-degree day, windows and doors open to catch any puff of moving air, every pilot ever minted has wished for air conditioning. With installed units starting at over $4500 and eating up at least 50 pounds of useful load, most owners are willing to sweat a bit and then climb to cooler air.
There is a much lower price alternative—portable aircraft coolers made from modern ice chests/coolers that use a fan to blow air across a heat exchanger full of cold water from ice (never, ever dry ice) to circulate cool air through the cabin.
At prices from $299 to $650, and weights of 30 to 63 pounds when loaded with ice, we wondered whether portable aircraft coolers are a viable option to installed air conditioning.
After using three of the most popular on hot days, we think that if an owner has reasonable expectations all of the units do a good job of cooling—after all, one pound of ice provides only 144 BTUs of cooling versus the 5000 to 10,000 BTUs from installed air conditioners.
The coolers were placed in the baggage compartment (except for the Arctic Air—the power cord was too short) of our test airplane, a Cessna T210, and flown out of Denver’s Centennial Airport. In each test the airplane was parked in the sun until the cabin exceeded 95 degrees F. Each unit was not turned on until the aircraft engine was started—the units plug into the cigarette lighter.
Our conclusion is that realistic use of a portable cooler is for taxi, takeoff and climbout to more moderate temperatures at altitude. It is then shut off. On descent, the cooler is turned back on and will keep the interior cool through landing and taxi in. Realistic cooling time is on the order of two to three hours—plenty for most flights. All of the units require some water to be added with the ice when the cooler is filled. Each uses a marine bilge pump—which must be mostly submerged—to pump the cold water through a heat exchanger and back into the cooler. A fan pulls in cabin air, blows it across the heat exchanger and the ice and exhausts it through louvers or a duct, into the cabin.
Keeping the bilge pump submerged is essential—meaning adding the right quantity of water and making sure the bilge pump is at the low spot for the deck attitude of the airplane during taxi and climb.
We tested the B-Kool, the Crosswind Cooler and Arctic Air Pack 52. We felt that all were satisfactory at providing an acceptable stream of cold air (temperature at the outlet was in the 45-50 degree F range).
We felt that the B-Kool was the best of the group due to its size—easy to get in and out of the airplane—the high velocity of the cold air from the duct and that it was the most user-friendly (everything was there and ready to go).
Arctic Air came a close second; while it was user friendly and held the most ice for slightly longer cooling, the power cord was too short to reach to the baggage compartment—which mystified us—and getting it into the rear seats of a Cessna 210 was an ordeal.
The Crosswind cooler worked well, but it was not user friendly—it requires a separate trip to a hardware store to buy ducting and paying $49.95 plus shipping for a 24- to 12-volt converter (it only comes as a 12-volt model). Also, it was hard to load with ice and keep the bilge pump submerged, and the extendable handle of the cooler kept opening and snagging when trying to put it in the baggage compartment.
The $299-$429 B-Kool Portable cooler series holds 25 pounds of ice and promises over two hours of cool air. At 11x18x16 inches high, it is the smallest of the units reviewed. The unit arrived ready to go—it was simply a matter of unpacking it, putting in ice (we used a 20-pound bag) setting it in the baggage compartment, adjusting the included flexible air duct to point forward over the back of the third row of seats, adjusting the baggage net and plugging the power cord into the cigarette lighter. It was the easiest-to-use unit of the three we tested.
As with the other units, the B-Kool struck us as being well constructed. The flexible ducting that came with the unit proved simple to use—it fit firmly, while being easy to remove, something that was necessary for getting the unit in and out of the baggage compartment of the test airplane.
The bilge pump fits into a receptacle in a bottom corner of the cooler—the best of the cooler designs. The ability to latch the bilge pump to the bottom of the cooler helped assure that it remained submerged. A longer hose returns water from the exchanger to the body of the cooler. It also functions as a drain hose to pump the water out of the cooler at the end of a flight—just hold it outside of the airplane and run the cooler for about two minutes. The unit can be turned on and off with an optional remote control—handy when pumping it out, but it adds $100 to the price.
The empty weight of the B-Kool is just under 10 pounds. With 20 pounds of ice in the unit, we found it was no problem getting it into the baggage compartment. The size should allow it to fit through most baggage doors.
B-Kool recommends completely draining the unit after each use. We agree—unless it’s clean and dry, interesting things grow where they are likely to cause problems.
The unit requires at least a cup of water to be in it on startup to work properly—the least of the three units.
The instructions are concise and clear. The warranty is one year on parts and a full refund if the unit is returned in original condition within 30 days.
The $499 Crosswind Cooler comes only in a 12-volt model (the website directs a customer that has a 24-volt system to a $49.95 converter from Sporty’s) and is built into a rolling Igloo cooler that has a handle that folds out of one end. The 16-pound unit is 13x23x20 inches tall and draws 6.5 amps. It does not come with ducting; instead the website and instructions direct the customer to purchase ducting and gives photos of various kinds, with costs ranging from $10 to $16. As the two other coolers included the ductwork and came in 12- and 24-volt models, we graded the Crosswind Cooler down from a user-friendly and cost standpoint. For our review, we omitted the trip to the hardware store and used the duct from the B-Kool cooler.
In use, following the instructions provided with the cooler for 10 pounds of block ice, 20 pounds of cubed ice and a half-gallon of water, the unit weighs 50 pounds.
The lid of the Crosswind hinges along the narrow side and the bilge pump and hose are connected rigidly to the heat exchanger on the underside. Once the lid is raised, the bilge pump swings up from the floor of the cooler. That made it difficult to add ice and then get the bilge pump back to the bottom of the cooler.
The inability to get the bilge pump to the bottom of the cooler may explain why so much water is required initially. It took us a few tries before we could get the bilge pump submerged enough for water to go through the heat exchanger and cold air to come out. Once it did, the outflow air was 48 degrees F; the velocity was satisfactory to reach the occupants of the front seats of a Cessna 210 from the baggage compartment.
There is no pump-out arrangement for the Crosswind cooler. After our test, the process of turning the Crosswind cooler on its side and getting it out through the baggage door meant a lot of spilled water and a soaked baggage compartment carpet.
The instructions included with the Crosswind cooler are terse, but adequate. The cooler is turned off and on by inserting and removing the power plug in the aircraft lighter. The cord is in two pieces—a short piece attached to the cooler itself and a long piece to the power receptacle—that are joined by a simple connector that was easy to use. In use, we did have the cord disconnect when an occupant inadvertently pulled on the cord while moving around.
There is a 120-day warranty on parts of the Crosswind Cooler—purchase price, minus $50 restocking fee, will be refunded if it is returned within 30 days.
The big dog of the portable cooler pack is Arctic Air, which makes a line of 12- and 24- volt portable coolers ranging in price from $495 to $650 depending on size (30 or 52 quarts) number of fans and whether they have ducts or louvers. The maker promises from one to four hours of cooling time, depending on size.
We reviewed the 24-volt Air Pack 52 with one fan and ducting. Everything was included in the package, including a second duct, power cord and drain line so the unit can be pumped out while in the airplane. The instructions were clear and concise.
As with the other portable coolers, the Arctic Air Pack 52 is based on a cooler, although it has an additional protective, insulating cloth jacket. There is a flap over the intake air vent on the top—it must be secured in the open position prior to operation. Comparatively, the Arctic Air Pack 52 is big: 14.5x24x17 inches high. Empty it weighed 23 pounds—we were able to put 40 pounds of ice in it, bringing in-use weight to 63 pounds. On its side, it fit through the baggage door of a Cessna 210. As the sides were smooth, maneuvering into position was easier than the smaller Crosswind Cooler.
However, once in position, and after attaching the power cord (it clips on and should not come off with an inadvertent pull), we were stunned to discover that the power cord was too short to reach from the baggage compartment to the instrument panel. That meant we had to maneuver the unit into the rear seats of the airplane—a major, unpleasant exercise.
There are two power switches on the power cord for the Air Pack 52, one for the fan and one for the pump. The instructions say that running the fan is the “low cool” position. It pulls air over the ice in the cooler and circulates it through the cabin. With the pump on, cold water is circulated through the heat exchanger, and is the effective cooling position, referred to in the instructions as “high cool.”
The Arctic Air cooler’s bilge pump is on a flexible hose—we had no trouble keeping it on the floor of the cooler as we added ice.
In use, the Air Pack 52 moved cool air through the cabin effectively—output air temperature averaged 48 degrees.
Due to the size, weight and need to position the unit in the back seat, the pump out feature proved valuable, although trying to hang on to the drain tube and then reach for the pump switch made us appreciate the B-Kool remote control.
At $299-$429 including everything, two hours of cooling and user friendly, the B-Kool series gets our vote for best of the coolers we reviewed. However, all of them were effective in use, providing a cooling flow of air through the cabin.
Going in with an appropriate level of expectations—ice does not replace installed air conditioning—we think these portable aircraft coolers are all a good way to make warm weather flying more comfortable.
Rick Durden is senior editor of Aviation Consumer and the author of The Thinking Pilot’s Flight Manual or, How to Survive Flying Little Airplanes and Have a Ball Doing It, Vols. 1 & 2.
This article originially appeared in the August 2014 issue ofAviation Consumermagazine.