The following was sourced from AVwebFlash 1 hour ago:

 

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"easyJet To Run Dry For Efficiency

 

Over the next 12 months, UK carrier easyJet plans to find out if they can improve the efficiency of their operations by removing moisture weight from their aircraft, the airline announced Wednesday. The carrier's yearlong test involves installation of 66-pound "Zonal Dryer" systems in four Airbus A320 aircraft. It is hoped that the system, provided by CTT Systems of Sweden, will remove up to 550 pounds of moisture per flight from the jets. The carrier says the weight is equivalent to removing 12 bags from the cargo hold and that could save nearly 10 million pounds of fuel, per year. The company also claims passengers will see a benefit.

 

 

 

According to easyJet, the move is in keeping with their efforts to be "as environmentally responsible as possible" and "using the latest technology to minimize the fleet's environmental impact." If the dryers work, the airline expects they could shave down the roughly $2.35 billion it spends on fuel each year while also "improving air quality for the passenger." The system works by using a fan, heater and moisture-absorbing silica-impregnated rotors to reduce water retention and channel dry air to particular parts of the aircraft to inhibit water retention. According to easyJet flight operations manager, Captain Chris Foster, "We're confident that we'll see significant and positive results on completion of the trial."

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According to easyJet, the move is in keeping with their efforts to be "as environmentally responsible as possible" and "using the latest technology to minimize the fleet's environmental impact."

As we know, running an airline is all about saving the planet. ^_^

 

On another occasion. I do understand that the air will now be even dryer than before. I hope I don't mix up things but didn't the latest and greatest tech on new planes actually aim for lower cabin altitudes and the possibility to allow for a more humid setup? At least for long range flights, so maybe that's the difference.

 

Well, if they install equipment (weight and maintenance) on the one end to save 'up to' 550 pounds on the air weight, the margins are small, right? Just pointing this out because we were wondering why that new light battery tech could be so important on other planes. However, maybe the long-term corrosion related costs are reduced on the planes with a 'conventional' fuselage setup. Just thinking aloud.

 

Either way, interesting read that is. Thanks for posting. :smile:

Just made me think.

It is hoped that the system, provided by CTT Systems of Sweden, will remove up to 550 pounds of moisture per flight from the jets.

Going metric, those 550 pounds equal 250kg of water. From the air on the plane.

 

Lets see. At 20°C and sea level pressure, a cubic meter of air can hold around 17 grams of water. Foggy. The cabin may be a bit warmer, so lets assume 20 grams. If you wanted to remove 250 kgs of moisture from the air, this would equal 12.500 cubic meters. An A320 passenger cabin holds 139 which is a bit off. A max of 2.78kgs of moisture in a sea level (cabin alt) A320's air. The whole air in the cabin is around 167kgs. Lets add a bit for the cargo compartment, but not much. I mean, you could fly an evacuated cabin, literally.

 

Now, all of this is with assuming that they really remove all of the moisture, which no passenger will like that much. Also, the moisture levels go down when looking at the normal cruise cabin alt (lets say 6000ft). I mean, they already complain about current levels for a reason.

 

Now there's a chance that I'm reading the announcement the wrong way or that I relate to the wrong levels and facts. :mellow: But 250kgs less weight? Lets see.

 

The current bleed air system already dehydrates the breathable air in the cabin due to various factors and the corrosion prevention. It circulates and mixes with fresh air, the one from cruise altitude. Not much moisture available, the overall amount will actually arise from your fellow passengers sweating and breathing. Still, that current setup leads to a rather dry cabin air. Hence the move on e.g. the 787 to lower the cabin alt and raise the moisture levels. Not to forget, humid air is lighter than dry one.

 

If you had a wet plane, collecting moisture and forming up 'clusters' in the range of those 250kgs, that would be a target. Condensation is an issue since the passengers add more than the air can handle, but current systems already collect and drain it over board, right? Corrosion and even hygiene are a concern then.

 

Well, to answer my own question, I think they are aiming at the condensate forming up. The rain in the plane.

Why would they reduce the moisture content in the air, as CoolP says, it's more moisture in the air that the passengers want, not less... :mellow: :huh:

I'm still a bit puzzled. Looking a bit into those devices, the surprising fact is that the Swedish company sells/promotes/uses them since over a decade. So I wonder why the easyJet move is new. Maybe because they now apply it to the medium range fleets? Are they standard on the widebodies? See this article from 2001. http://www.economist.com/node/655691

 

They are describing the principle.

CTT's Zonal Drying System takes the moist air leaving the cabin and feeds it through a rotor impregnated with silica gel. This removes the moisture. The dry air is then blown between the cabin wall and the aircraft's skin, absorbing any condensation that has formed there. Then, a stream of warm air is run through the rotor unit in the opposite direction. This absorbs the moisture from the silica gel and feeds it back into the cabin whence it came, keeping the passengers comfortable.

Interesting. If it really works that way.

 

I understand that the moisture can be a problem, that e.g. clogged drain lines or frozen ones are a pain, that the electric systems and wirings don't like it and that old or improperly applied insulation materials may even absorb some amounts. And there's the corrosion and even fungi stuff too. However, do you really save weight when you circle the moisture around like described in the article? Following the description, it just takes away the 'water' from one end and transfers it to another one.

 

I'm not too happy with the article but it at least shows that the idea seems to be a bit older.

 

Edited. Installations go back to 1998, starting with a MD-80 fleet. http://ctt.se/custom...ents___279.aspx

 

And the article leaves out this fact, actually explaining the weight savings. Must be more efficient than the drain routes alone.

This moist air is re-circulated in the cabin via the aircraft's air conditioning system or let overboard through an outflow valve.

http://ctt.se/howitworks___225.aspx

Why would they reduce the moisture content in the air, as CoolP says, it's more moisture in the air that the passengers want, not less... :mellow: :huh:

In the passenger cabin, yes. In other parts of the airplane, not so much. Especially not if it condenses and pools in various nooks and crannies.

Yeah it's not for the cabin. It is pretty interesting to see how it will help corrosion on some parts as well.

Last week when the highs were in the teens, my sinuses started getting very dry. Eventually, I got a bloody nose. My wife also a few years ago got daily bloody noses from the very dry and warm indoor location where she was at. I wonder how many people would get bloody noses from it being that much drier.

Is it April the first already ? my how this year has flown by.