I'm anticipating a battle with the H&A guy. We have two auxilliary H&A return ducts in the ceiling, one in the master bedroom and one in the hallway. The primary return is at the other end of the hallway in the wall down near the floor. The H&A guy did not think about how to a return filter grill for the returns in the ceiling. His worker just terminated a duct in the ceiling. The framing around the ducts in the ceiling do not accommodate a return filter grill.
When we asked him about putting filters in the ceiling, he said it can't be done now. So he installed some sort of inline filter at the end of the auxilliary return where it meets the primary return. He does not intend on providing us a return filter grill where the far end of the returns terminate through the ceiling.
The picture shows a temporary filter my wife cut to size and stuffed in the duct in the ceiling to prevent construction dust from entering our HVAC ducts. I don't think I'm going to accept not being able to put a filter in the ceiling. You can see the amount of dust that collected in just a few weeks, albeit during construction. I don't want years of dust collecting in the ductwork of the auxilliary return. I'm expecting the H&A guy to refuse to change the ceiling grills. Keep in mind that the framing in the area above the ceiling can be accessed from the attic by unscrewing one or two pieces of OSB.
Remember, this is the same guy who has been very inflexible and hard to work with. For example, he ran the bathroom shower vent ducts so that condensate drained toward the inside of the house instead of the outside of the house even though I asked him before he started to do otherwise. He didn't forget; he was just obstinate. We had to change the ductwork ourselves after he left. That's just one of many examples of his inflexibility. He is also someone who has been bad about no-showing and not returning calls.
We'll see how the ceiling return filter grill issue turns out. I plan to have him finish all his other work before I re-adress the grills with him.