Can anyone tell me if the supply duct design is optimal for this ERV install? The wye seems to limit airflow to the 45 degrees elbow compared to splitting it 50-50 with Y.

The ERV is Panasonic Intelli-Balance 100 Energy Recovery Ventilator (Temperate Climate – FV-10VE2). All duct are 6 inches rigid, 26 GA. Will be using 6 inch round grills for supply and exhaust (https://www.supplyhouse.com/Fantech-…lar-for-6-Duct). Already did the project halfway and I have doubt regarding using wye and Y for the supply side. They are in conditioned space.

Does anyone think its better to use 4 inch on the 45 degrees of the wye branch’s for the supply air? And also reduce the duct to 4 inches before it goes to each rooms? That way the 6 inches duct will become a supply trunk and all the supply branches will be 4 inches.

Too late to do anything on the stale air pickup, they are all 6 inches all the way to the grille.