New member here. Thanks for taking the time to read this.
I have two return air grills, each approximately 14x30. I began to use pleated air filters with a high Merv rating (10 or 12 I think) because I was concerned with air quality in my home. I began to notice that when the air came on, the filters would be pulled out of place, and nearly sucked into the duct because of the air pressure. I searched for grills that could trap my filters but didn't find any at the local home improvement stores. Instead, I set up some velcro around the rim of the grill. I would then attach velcro to each new filter as I installed them. This kept the filters in place. I then spoke with someone with several years of A/C experience, and he explained I shouldn't be using such a restrictive filter. He said that plain, cheap, fiberglass filters are "nearly" as good at trapping air born pollutants. Additionally, they restrict a lot less air flow and are better for your a/c unit.
I finally honored his advice and custom ordered a box of 12 fiberglass filters. Installed them, A/c came on, and up went the filters. Seems that the pressure is so high that its even pulling these less restrictive filters. Is that much air pressure normal? Should I go back to searching for a grill that can trap the filter in place? Should I stay with the cheap filters, as long as I change them out monthly?
Also, one of the returns is just outside the master bedroom. Anytime that the unit comes on and the door is only partially open, the pressure will slam the door shut. A/c guy (see above) recommended that I wedge something in the door to help the air escape more easily, and thus improve the effeciency of the unit. Thoughts?