Gas and Oil Home Heating Furnaces - new furnace question

We just had a new Trane natural gas furnace installed. When it cycles on, the air coming out of the blower is on the cool side. The thermostat says that it is 70 in the house, but it doesn't always feel that warm. Is there something wrong or does it have to do with the fact that the old a/c was taken out and a new one isn't there yet (waiting until February for that) or maybe because our installer recommended that we have a larger return air duct-he will be doing this later.
Also, the rooms furthest away from the unit get very little air flow. I thought a new unit would help this matter, but it hasn't.

Any advice is appreciated.

You should talk this over with the installing company. They just need to do some balancing.

As for the air being on the cool side when it 1st comes on, it's probably just blowing out the cool air in the ducts untill the air that goes across the heat exchanger reaches the duct outlet. Hows the air feel after the furnace has been on for maybe a minute.

maybe because our installer recommended that we have a larger return air duct-he will be doing this later.
Also, the rooms furthest away from the unit get very little air flow. I thought a new unit would help this matter, but it hasn't.

That can help a lot here with a new duct. Id check and see what speed they have the blower on now. Could be they can kick it up and get more air down the line there for you.Are how is the duct work there on the heat is it ok

ED ;)

What model did you get? varible speed?