You want to run 1" or so tubing all the way too and from the chiller. You will get way less restriction (head loss). And I'm with you. I'll never understand whay they use such small ports on some chillers. I cut them out and weld in 1.5"ers
I see no reason why you cant use the small pump in the sump. But put the pump in the return pump section that is bubble free. Then you are putting it back into the first section, still bubble free. You dont want bubbles around the chiller coil anyway. The baffles will handle that little extra water.
I really dont see the drop you are saying across the baffles with putting the pump in the other side, unless your sump turnover rate is very low. Your baffles are very close together though. You want it on the other side anyway to stay bubble free.
Your turnover rate should be enough to properly mix the flow of chilled water with the return water without short cycling the chiller. Ideally, you only want a degree or 2 temperature drop anyway across the chiller coil.
I see no reason why you cant use the small pump in the sump. But put the pump in the return pump section that is bubble free. Then you are putting it back into the first section, still bubble free. You dont want bubbles around the chiller coil anyway. The baffles will handle that little extra water.
I really dont see the drop you are saying across the baffles with putting the pump in the other side, unless your sump turnover rate is very low. Your baffles are very close together though. You want it on the other side anyway to stay bubble free.
Your turnover rate should be enough to properly mix the flow of chilled water with the return water without short cycling the chiller. Ideally, you only want a degree or 2 temperature drop anyway across the chiller coil.