I have a HVAC question. I bought a huose last year that is about 1600 sf on the main level which is air conditioned. I'm told I have a 3 ton unit, it struggles to keep our house cooled. We set it a 77 degrees and on days when it gets 90 outside it hardly ever stops running. I get high electric bills (250-300 a month). My neigbbor tells me I should invest in a heat pump that is staged. But he also tells me if I up my unit to a 3.5 ton or higher that the duct work still may not match the bigger unit. My head is spinning. Does anyone have some good advice?