If the balls were inflated in a 70 degree locker room, then brought into 40 degree weather, the pressure will fall. Same amount of air, just lower pressure.
ABSOLUTE UNITS:
plus 460 to go from F to Rankine (R)
plus 14.7 to go from PSIG to PSIA
Conditions:
Field temperature at half time: 45 F
Regulation ball pressure: 13.0 psig. (actually 12.5 to 13.5 pig)
Depressed ball pressure: 10.5 psig. (assumed. Going for a 2.5 psi deflation)
Room temperature required: xx F
Revised conditions:
T2a = 45 + 460
T1a = T1 + 460
P1 = 13.0 psig + 14.7 = 27.7 psia
P2 = 10.5 psig + 14.7 = 25.2 psia
Ideal gas equation is : PV=nRT
Rearrange to: (PV/nRT)1=(PV/nRT)2
Equation:
T2 = (T1 + 460 ) * (P1/P2) - 460
P1/P2 = 24.7/24.7 = 1.10 (So 10% hotter is required)
T2a = 505 R * 1.1 = 555 R
T2 = T2a - 460 = 555 - 460 = 95 F
So the a temperature change scheme requires a room 50 F hotter than field temperature.
It also requires that the balls be checked in the hotter room.
To avoid the same advantage for the other team, you need to have their ball room at field temperature.
Its even better if you inflate them in a sauna at 115 degrees and take it immediately to the weigh in. I don’t know if that happened, but that might explain it.
It would lower the pressure by about 1.3 psi.
If that was the temperature differential.
The rules apparently do not say where, when, how, with what, at what temperature, etc. that a ball must be inflated.
It only says they must be between 12.5 and 13.5 psi.
Does anyone know (including link) if each team inflates their own balls or if referees inflate the balls and then give them to the team?
If NE inflates theirs to 12.5 and Indy inflates theirs to 13.5, they would both be legal, but NE’s would be underinflated once they hit the outdoors and got to air temperature.
Also, Aaron Rodgers says that the officials will deflate footballs. See here: http://www.nydailynews.com/sports/football/aaron-rodgers-calls-refs-deflating-balls-major-problem-article-1.2086653