I am currently retrofitting an apartment with central AC. My HVAC contractor has installed the furnace and the duct work, but I am concerned about how the ducts run:
One duct has two 45 degree bends and three 90 degree bends, another has five 90 degree bends, two right next to each other, basically forming a U. The total length of each duct is under 20 ft, hooked up to a 2 ton unit (there are also two smaller ducts, less than 4 ft each). I think it's possible without too much effort now to reroute the ducting to eliminate two-three 90 degree bends from each duct.

My question is whether the bends will negatively affect cooling efficiency. Is there a maximum number of bends that can be put into a duct? Should I have him reroute the ducts to minimize the number of turns?

Thanks for your input,