[GT1980]

PB Blaster (get more if mentioned)
3M 33 and 88 tape

Memorize btuh= 500 x GPM x (EW-LW, temp diff's) = 1.085 x cfm x air temp diff (standard ambient, etc)

get a 20" stem from cutting-off handle of a boiler brush you would use to knock debris of fin-coils of RTU's etc for to put into your variable drill and SPEED CLEAN dusties from large coils before other cleaning! -not that which can pierce cu tubing- - saves a lot of time, in a light leather work glove, though. Forward and reverse works so fast, you may want a mask for the cloud sometimes!