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.
Keywords: Selective androgen receptor modulators, SARMs, Sarcopenia, Function promoting anabolic therapies, Cachexia. 1  As men and women grow old, they lose muscle mass, muscle strength, and leg power (1,2,3,4,5,6), mostly due to the preferential loss of type II muscle fibers (5).