Pungent smell disturbing u during your sleep time due to mold growth. A fire-like smell indicates that some electrical components are burning inside the system. A gas smell indicates leakage of Methyl Mercaptan, which can be dangerous.
If you turn on the AC after a while, you may notice a rotten egg smell coming from the unit. Birds and insects can get into your system and die, causing this weird smell.
No appetite for your dinner / family time ??? Sick and tired???
