Most consumers believe that if there is no odor then there is no Chinese drywall. not true. The degree of smell varies greatly in each home, as does each person's ability to detect the odor. The strength of the smell also depends on the quantity of drywall was used in the home and the quality of paint and primer. Homeowners have reported no smell, but their home clearly has Chinese drywall. In short, do not rely on smell alone.
The strongest indicator of Chinese drywall is black corrosion of copper and porous metal surfaces, including electrical wiring. Check the interior and exterior of the HVAC unit (air conditioner) and look at the copper lines and coils. The majority of homes with Chinese drywall have had air conditioning problems, specifically premature replacement of the evaporator coil. You should also check the interior wall electrical receptacles and switches to see if the ground wires are blackened. In a new home.