Thanks to you all. Need you guys at my house in the east. I will check the return and supply temps most likely tomorrow morning. People who complain about something usually are right, its the people who do not want to hear it and just want the money that turn everything against you making you look bad, Thats why i do all i can myself. I do a better job than the techs out there you hire, But heating is not my forte. Though through all my research i know more than the tech. Will get back tomorrow. My tech new nothing about merv ratings and filters.
if the techs were that bad and they turned the fan speed up maybe they didnt need to and you have more cfms than you need . how many hits come off the supply duct and what size is it and how big are your returns and what size is your return duct. this is why you need a pro to look at it.