Adding Return Air to improve air flow
I have 2 HVAC units. 1 for upstairs (2200 sq. ft) and 1 for downstairs (2300 sq. ft).
It was suggested to
Add to the Master Bedroom (15x17) down stairs a Return Air to Improve Air Flow and Air Balancing.
Also maybe for the 3 bedrooms upstairs, to add a Return Air to each of the upstairs bedrooms. The upstairs bedrooms face West and get a lot of heat.
Question:
1) Will adding Return Air in each of these bedrooms, make it cooler or warmer (depending on the season), by pulling the warmer or cooler air out of those rooms?
2) If we add 3 more return air to the upstairs (then there will be 4 return air total), is that efficient? Is it better to just add the return air in the room that which has more issues with the temperature? The rooms upstairs are 11x11, 11x12, 12x13 (this is the room that has the most issues).
3) The cost is $387 to add the return air flow to the master bedroom. The attic is above each of the bedrooms, so the return air is easy to install. Is this cost reasonable and will I get enough of a benefit by adding this? I have not gotten a cost for the upstairs bedrooms, but is this cost reasonable for those rooms also?
Also this is in Houston if that helps when determining if efficient.
Thanks for your help.