You can block it. The unit won't heat or cool that room anymore though. The return air does effect supply air temp. And heat pump efficiency. With a 60 degree return air temp, the heat pump is more efficient then with a 70 degree return air temp.
We are simply getting contaminated causing otherwise healthy folks to lose the function of their kidneys and for a senior citizen who is already suffering sarcopenia this can be a death sentence because of the complexities associated with Renal Failure.
Sarcoidosis is not a death sentence! In fact, once diagnosed, your doctor s first question will be to determine how extensive the disease is, and whether or not to treat at all in many cases the choice will be to do nothing but watch carefully and allow the disease to go into remission on its own.