NEW YORK CITY
Energy Savings % Indoor Vs. Window R/F
Assuming that the A/C is Off (Outdoor is colder than kitchen)
B = Average Outdoor temperature (temperature of Window R/F's Condenser).   
C = Average Indoor temperature, 70 F or higher (temperature of Indoor R/F's Condenser). 
D = Average temperature of the evaporator (set constant at 29 F). 
Energy Savings % = H = (C-B) / (C-D)
Fahrenheit B C D H
JAN 31 70 29 95%
FEB 34 70 29 88%
MAR 42 70 29 68%
APR 53 70 29 41%
MAY 63 70 29 17%
JUN 72 72 29 0%
JUL 77 77 29 0%
AUG 76 76 29 0%
SEP 68 70 29 5%
OCT 58 70 29 29%
NOV 48 70 29 54%
DEC 37 70 29 80%
Average Energy Savings %  40%
Exact same as above except in Celsius
Celsius B C D H
JAN -1 21 -2 95%
FEB 1 21 -2 88%
MAR 6 21 -2 68%
APR 12 21 -2 41%
MAY 17 21 -2 17%
JUN 22 22 -2 0%
JUL 25 25 -2 0%
AUG 24 24 -2 0%
SEP 20 21 -2 5%
OCT 14 21 -2 29%
NOV 9 21 -2 54%
DEC 3 21 -2 80%
Average Energy Savings %  40%
Windowrefrigerator.com
PATENT PENDING