We are planning to add a room to our house, so load on our current a/c unit will increase. Our current a/c system has a one component in the attic (this is the part through which the cold freon runs), and one component outside the house (which has a fan and compressor). If I want to increase the airconditioning capacity of my system, do both components have to be upgraded or only one? The reason I ask is that it is going to be a pain to change the unit in the attic. (I wish that unit was in the basement, but it isn't). Thanks in advance for feedback.