Equipment the same on both bids.One bid has 10 supply registers to rooms and 3 return airs.Other has only 5 supply registers to rooms and 2 returns.One or two rooms on addition?
For a 2 ton HP system you need a Minimum of 800cfm (cubic feet per minute) in supply runs and a minimum of 800cfms in return air for the system to exchange enough air for the HP to work properly. (1000 cfm of each even better) To properly evaluate bids you need diameters of supply pipes to each register and diamensions of Return air ducts to calculate total cfms. Hope this helps.