Insufficient airflow to front bedroom
Raising fan speeds during heating season can be counter productive.  Shutting vents off does not mean more air will flow as we desire.  In most instance power consumption increases.  The best option is to increase duct size for a significate portion of the run if the duct was properly sized to begin with. Duct runs should never run over 25 feet remaining the same size.  Duct runs generally should be limited to no more than 20 linear feet. A 100 square foot room generally will need a 6&quot; duct.