some observations
I've got rather alot of hardware here. I over the winter went thru the exercise of replacing all the old [most of them worn out] glass tube crt's with 17" LCD units. [mostly viewsonic bought 2nd hand for good price] and noticed the following.
1 the ambient air temp dropped by about 7 degrees.
2 the power draw from the grid dropped by about 5 amps. [measured at the UPS units, everything here runs on a ups]
fyi; 9 monitors were replaced.