before switching to 220v I didn't want to stress my 15 amp circuit and wanted some headroom for the 85 degree limit in case my garage started to heat up. 
Currently my garage is staying around 73F with an outside temp of 45F, last week outside temps were 70F+ and the garage was up to 83F.  I also want to keep the noise down as much as possible as to not piss of my neighbors or HOA.  With no current way to remove the air from my garage, I'm stuck running them a little slower.  I'll probably start ramping them up after a few days to find the best noise / fan speed / hashrate combo though.