I purchased a nice mobile home last year. I have had nothing but trouble with my hvac. After the ac and heat kick off, the ducts in my master bedroom boom and pop and the air handler pops really loud. It does this until it kicks on again. It has never stopped after a year and seems to be getting worse. I've had several people come out and NOTHING can be done. They all tell me that they don't work on mobile homes because the positions of the ducts under the belly. It only does it in my master bedroom which is adjacent to the air unit. I have no warranty anymore and no options. I can't even pay someone to replace all the ducts. It's only a 60 foot trailer. Before I do this, does anyone have ANY suggestions? They tell me it's simple expansion and contraction, but I do not believe this. If that were the case, it wouldn't be isolated and it wouldn't last hours. It would do it in all areas of the house and it would be over in a few minutes. I've even lowered the fan speed. That didn't help. Any suggestions before I go the window unit route? Thanks!