I am baffled by how to cool my upper floors more efficiently during the summer months. my upper floors are always hotter than the first floor. I have central air. Any suggestions?
Hay Carter, welcome to the site. You always want to start by assessing the venting in the attic. So we need type of roof, type of vents at peak, soffit vents, rooms in attic space. and insulation in the attic.
Have the flow rate from your registers measured. Typically, there are big leaks in the ducting which sends very little air to the upper floors.
Nealtw is exactly right about the venting too. If the attic is unvented, the hot air will just sit there and heat your upper floors.
Lastly, you may have insulation deficiencies and poor windows. All of these contribute to a better HVAC systems.
Do all these steps then come back . . . we can talk then!
If you borrow a 5000 BTU window AC and it runs half the time or all the time you will have some idea of how many BTUs/hr you need to remove.
I have used a duct booster fan to compensate for too little heat. If you go this way get a variable or two speed unit. A 12vac or 24vac motor puts less constraints on the proper wiring to it.