What is temperature blowing out the register supposed to be?

by Ann
(St Louis, MO)

I just had a carrier heat pump air conditioner installed. The temperature blowing out did not seem cold to me. They tested the farthest vent in the house from the unit in basement. It read 58 degrees? Is this appropriate?

The thermostat is set on 73 degrees and when it reaches 73, it really does not feel a comfortable 73. I am assuming it might be the humidity....the humidity in one room was 48 % and in another room, it was 40, another it was 42. Does this sound right? My old unit felt much cooler at 73.