Hi. My husband and I lived in a one bedroom apartment (just a rental) in NYC that had a very loud Trane, heating/air conditioning unit. It was exceptionally noisy when it ran, and it clicked on/off very loudly. When we moved in, it was a brand new, luxury, "green" building, and we were devastated with this unit. We could never sleep with it on. We had a Trane representative come to check it out, but there was nothing that he could do. We purchased the best soundproofing material available (super thick MLV with super thick foam) and built a wooden box around it with the soundproofing material. It did not help much and probably wasn't worth the effort.
I'm sorry!