Kramer,
I love to steer
with you its hilarious,you seem to know my history..its not reciprocal and i hope you dont mind.
Please read my post slowly....and digest...then type.
Now if my posts are generally wrong,please excuse me..as still waiting for proof of it and I am not considering your inputs as facts and correct either.
If you prove me wrong with facts/docs rather than pure say then yes ill mea culpa anytime...even with you...
Yes, you are right that the recirculation fans are indeed in the checklist. I was looking at a an older version (800) QRH of my own computer
Glad we cleared that one early enough in the discussion.
Now back to the subject,
You write:
Do you really think they would have built in a heavy recirculation fan system, that requires maintenance and cost fuel every leg to carry, if the penalty was only a few kg of fuel of omitting it?
I never said so...but as usual you put words in my mouth...they built it to meet the recirculation output of the packs up to the published service ceiling.
I said MEL may not reflect a fuel penalty as it may be really minimal..
Hence my reference of the AMM:
It provides optimum airplane performance, but requires a recirculation fan to meet de- sired cabin ventilation rate. As cabin altitude increases, the pack valve is biased to supply a lower airflow rate.
You write:
If they are/it is on or off, doesn't change a thing about the output of the pack (which is always the same for the selected flow rate).
I never said the opposit, i said if the fans were off,more bleed output will be required for the packs to give their scheduled volume of air....this uses extra fuel,as minimal as it may be.
After i wrote:
Quote:
If the recirc fans were off,or non existent,the bleed demand would be higher since all air source to the mix manifold would come from the packs alone.
You wrote:
Nonsense... That is the myth I mentioned.
So Here form the AMM:
Recirculation System
The recirculation system uses a fan to move air from the passenger compart- ment to the main distribution manifold. This reduces the amount of air that the packs need to supply.
You understand that sentence?
...aka if a recirculation fan(s) is/are not there, the desired (regulatory required rate for certification) will NOT be met.
I never said otherwise.
But if the aircraft is full, your cabin crew will most likely complain that they can't breathe in the cabin and ask you to turn the temperature down, even by normal temps (as they can't find any other reasonable explanation for the sticky air).
Well here im baffled....when the fans are off the air becomes sticky?
So you are saying that the recirculation fans remove humidity?
My ears are wide open.