Work with your contractor.

>Query-after new flexible ductwork was put in-the air flow is much much stronger!

My suspicion is: the dealer installed a higher rated unit. Like if you had 3T blower contractor installed 4T (48000BTU). He may be able to switch furnace to a lower blower speed for heating.

>The installer says its bc he needed to adjust the flow-using the dampers that were part of the new ductwork.

Ok, he can do that too.

>Is there much of a difference in cooling/heating where vent is..

It depends if you are in heating or cooling dominated climate

Im in Houston fyi-warmer here. for the blower I need to find out about the speed for heating somehow. Odd thing is in april this unit was installed-the ductwork just done past week-now these issue with hot and cold spots-and intensity of the heat and ac is very uncomfortable. I had him here other day-lowered drafter for my room..

Sounds like the unit is oversized. If your unit cools too fast during the cooling season OR heats too fast - it is oversized. For cooling you will feel uncomfortable and sweaty. During the months of July and August you blower should have a long runs; and if instead it cools really quickly - it will not remove enough moisture [latent heat].

You typically move one of the blower wires from spare to heat to lower and raise blower RPMs.

so the blower speed-not the same as fan speed correct? On my nexia ap for the unit it shows fan speed 50 percent.

Reasons for Room to Room Temperature Imbalances.

https://www.heating-air-conditioning.org/

Have you ever noticed that when you enter a certain room in your house, it’s always warmer than all the others?

Or have a room that you know has the coolest temperature in your house? No matter what you set your thermostat to, those rooms are always hotter or colder than the others. Your living room may be the exact temperature you want, but your bedroom upstairs is freezing. It can be aggravating and uncomfortable and, while these temperature imbalances are frustrating, they may be warning signs of a much larger issues.

So why does this happen and what can you do to fix it?

First, check for the following common issues:

Air Duct Problems: If your air ducts are crushed or kinked, certain areas of your house won’t get sufficient air. Air duct leaks can also cause uneven temperatures, among other issues.

Dirty Air Filters: Clean air filters allow air to flow through your home efficiently. If your air filters are dirty, it restricts airflow therefore affecting the amount of cool air circulating throughout your home.

Open Windows: Cool, air conditioned air can escape out of open windows leading to uneven temps in your home.

Closed Vents: If a vent remains closed in a room, it restricts airflow leading to a warmer temperature than in other rooms of the house.

If it’s not one of the problems above, the next likely cause is an unbalanced air conditioning and heating system. You’ll need an AC company to balance it.