[ctpd814]

I think I would check with other 300 owners and see if they feel a second a/c is needed. I think it would depend on how your garage is being used. If you are just using it as a garage, then I don't think it would be needed. If you are using it as living space, then I would consider it. If you were to add a second unit, I am sure you will want to run them at the same time at least on occasion. I would have it wired so they could both be run at the same time.