A/C suction pipe sizing
Looking at the table for my 5 ton Carrier 2-stage A/C (soon to be installed), it shows that using a 7/8th line instead of a 1-1/8 line would result in ~2% less efficiency when running at maximum, and maybe 1% less when running in low stage (approximately 3.5 ton).
Since the a/c will mostly run on low stage, are there other advantages/disadvantages in selecting the pipe size? I have read that one disadvantage to a larger pipe is reduced velocity, resulting is less oil carried back to the outdoor unit.
This is for an install with maybe 90 feet effective length, with coil in attic about 15 feet above the outdoor unit. Obviously, both materials and labor are lower with the smaller pipe.