I have a carrier weathermaker. 58mxa080-12 serial number 4899a02558 that I am looking to add air to and I need to Know if this is a 2,3,4-ton blower. This house was added onto and now almost 3000 square feet. Primary heating source is wood but I would like to add a 4-ton heat pump or a/c. How do I find out what blower this has?