The second floor is often much warmer than the first so one area of the house often seems too hot or two cold.
Getting better ac to the second floor.
Because cold air sinks it can be very difficult to get both floors comfortable when they are on the same system.
The added cost of the second unit can also be offset by the ongoing energy savings.
Almost certainly you should shut off the upstairs ac completely.
This is particularly beneficial for larger homes.
If your air conditioning unit is the right size for your home but you still need to cool down either just one room or the whole second floor you ve got options.
Check the temperature of the second floor rooms.
The second floor is acting as a huge air gap between your roof and the down stairs.
Positioning a window air conditioner in those places will allow the unit to better regulate the heat on your second floor.
Air filters sometimes the fix is quick and straightforward such as increasing your air flow.
However when the thermostat senses that the temperature on the main floor is the temperature your hvac system has been set for it will turn off the ac.
In many older homes it is difficult to keep the entire house at the same temperature.
Much of this depends on your home s floorplan and how you plan to use the air conditioner.
The only reasons i can think of to leave it on would be.
If you have the option of adding a second system i would do this rather than adding ductwork from the 1st floor.
Ensure that the air conditioning unit is on and wait one hour.
It doesn t know it s hot cold up there.
If they still are warmer then the downstairs rooms close the downstairs vents more.
Ideally you would also seal off the second floor as much as by shutting a door at the top or bottom of the stairs or installing a curtain across it or something.
Hot air rises so the second floor is naturally going to be warmer.
Despite your air conditioner repair man saying the ac is tuned up and running properly the bedrooms on the second floor are so hot many in the family choose to sleep downstairs.
It can never run enough to cool heat the upstairs space if it s being controlled by the better conditioned downstairs.
Of course this means that your second floor has not yet sufficiently cooled.
Another option is to install a single air conditioning unit with two or more thermostats.