Hello All! My house is 40+ years old, actually its probably closer to 50 years old. My family has been living here for 25+ years. Now originally the house did not come with central air conditioning and was installed about 20 years ago. Last year we had to replace, pretty much the whole unit(the outside compressor and in the inside of the house the heat exchange, and such, sorry I do not know much about the technicalities of it all). Anyways, we do not have more then one thermostat or compressor and the thermostat is downstairs. The downstair's temp is great---always great, I have absolutely no complaint here. However, go upstairs and there is a noticible difference in how much hotter it is. Upstairs, the cool air comes out alot less powerful and Im guessing once the thermostat reads 75 downstairs the A/C shuts off regardless of the temp upstairs. I was wondering besides having to buy a whole new unit for the upstairs is there a way in wich I can increase the air flow upstairs or any other recomendation for cooling the upstairs would be great. also, we put new insiliation in our attack.