Former A/C service guy who hung up tool pouch in 1989 has questions on newer multiple capacity units. I need to replace my split heat pump (condenser on ground outside with air handler in garage). 2 story house with only a single downstairs return. Pro's & Cons of dual compressor units vs a single variable speed compressor i.e. Trane vs Rheem. I am concerned about both concepts that seem to rely on outside air temp which solely determines running capacity.
If I had a manual over-ride that I could use with lower outside temp but very high indoor load (indoor cooking with party and packed house etc.) I would feel better about the concept. I am concerned with auto control only over capacity. Also with the master bedroom upstairs also a vaulted ceiling it seems the air handler has to run very fast to push up enough air volume. That room would seem to suffer most when the unit would be running in the lower capacity mode making the up-down temp difference even worse. I know running the indoor fan continuously would help with that but it is so noisy now in the family room where the single return is we have to turn the TV up 4-5 steps to compensate. It gets to be really annoying.
Of course with the thermostat downstairs near the single return it wouldn't seem to bother that area as much as upstairs which is always a problem even with a single speed unit.
Getting replacement quotes now so any personal insights on best unit & other concerns to consider appreciated. I know a return upstairs would be best but existing construction really won't allow it. I may forgo the variable capacity route anyway as it only seems to add about .5 seer.