Hello, Murphys law abounds at my house. Just replaced all sewer pipes to main line, and now my air goes out. I have an older unit, which i believe is 3 ton. Unfortunately I can not afford a new unit at this time. My compressor went out, and I found a used but in excellent shape outside unit, the only prob is that its 5 tons. Would it work at least for the summer? And yes, I am going to have a licensed hvac tech come and install it. Thank you.