I have a 1973 Hallcraft home on a 2167 square foot home in Phoenix Arizona. The original duct works consisted of 3 air intakes throughout the house, two of which are within 10 feet of each other on one side of the house and the third on the far side of the house in the hallway. These intakes are at floor level, are about 8 inches in diameter and drop into the concrete slab. The duct work ran to a closet in between the two air intakes closest together that used to house a heater for the house. Over the years, as heat pumps became more popular, they did away with the heater in the closet and ran a duct bypass up through the attic where they put a heat pump on the roof.
I am trying to expand and update my bathroom and one of those air intakes is directly in my way. My question is this: Can I get rid of that air intake and will the heat pump still work efficiently if I do?