Gas and Oil Home Heating Furnaces - Return registers

I have a heat pump forced air system (in Connecticut) with resistive electric backup. The system appears to work as well as can be expected in this climate. There are several return registers. Some of these are paired. That is, there is one return duct that leads to two wall registers, one near the floor and one near the ceiling. Each register can be set to be opend or closed. My question is: which register should be open- does that change with the season (heating or cooling)?
thanks....ralph

Open the low return and close the high return in the winter because you want the coolest air in the room brought to the system to be heated and the warmest air to stay in the room.

The reverse is true in cooling. Open the high return and close the low return in the summer because you want the warmest air in the room to be brought into the system to be cooled and the coolest air in the room to stay.

Many thanks....ralph