AC grill/vents

I have to say that I got every last bit of the 30 years out of my fan coils in the galley and salon units. I ran them right up to the point where they were blowing rust dust out the vents (and sometimes water from the massive condensation that occurred all over the entire metal box), finally seized, and I could smell the burning odor. Once they started blowing rust dust and debris a few weeks ago, I ordered two new fan coils. They were essentially crumbling from the inside out.

The 30-year-old condensing unit is still going strong. New fan coils will be here on Friday, along with new controls and digital thermostats. Can't wait!!! Its really hot down here in Miami. This should solve the "amnesia" problem that system had when it came to coming back on. I even tried swapping out thermostats with one from downstairs - that didn't solve it; this will.

It sure is a lot of work. I'm doing all of the prep before the new units arrive - taking apart what I can before the system is evacuated; installing insulated flex duct in the old chases; and I have to cut the access hole in one cabinet a little bigger because the new unit won't fit through that hole. I have found that the Hatteras cabinetry was built just as tough as the hulls - glued and screwed. I can take every screw out and the thing is still solid as a rock. Now I remember that - taking the old wet bar out of here was very much destructive disassembly.

Doubt I'll get 30 years out of the next set.

Now, for my question - does anyone have a source for the vents? I'd like to increase the ouput area on one of them a little but, and increase the draw through on the other to at least match the size of the face of the coils. I can't seem to find vents that will fit into an opening that is 16" wide. My rough openings are 16" x 4" I'd like to increase them 16" by 6" or 8".