8 year old carrier replace/repair

[beenthere]

Turning vanes aid in reducing resistance to air flow. help to guide the air through right angle turns.

[tedkidd]

Sorry BT, that question appeared while I was composing and I never saw it, or I'd have answered it. Pad's offer convenience but they are slow to compose and type on.

[udarrell]

Well, a heat pump has an accumulator & if it has TXV metering devices U could maybe use 330-CFM of airflow per/ton of cooling; or, a possible 1650-CFM with the 5-tons.

The duct airflow velocities & pressure appear way too high with probably a high rate of duct air leakage.

The turning vanes are very important to that design; - with that duct system lowering the tonnage is IMO, critically important; but see what an audit &/or a load calc shows what is needed.

If U live between Jacksonville (94-F;46% RH) & Tallahassee (92-F;48% RH), that normally means a lot of grains of air infiltration moisture & indoor humidity load.

How many square feet (sf) is your home & is it loaded with windows?

Seems to me in that climate U don't want an over sized condenser or evaporator coil; it needs long runtimes & a cold coil.

You really ought to have a Home energy Efficiency Audit so U know what U need to do to make your home & duct system more efficient.

The initial sizing of the unit & duct system appears to be a real problem.

Your situation illustrates why the first install; design, & setup is so important.

You got a lot of good advice from everyone...

[kilobravo3]

I really appreciate all the responses, there is clearly a wealth of information here. I am going to have another contractor out to take a look at things and give me an assessment, but that begs the question, How do I find contractors who actually know the things that you guys are talking about here? It seems like every time I have someone out, they don't have any of this type information. If I start asking questions from things I've learned here in the past, I just get a blank stare and something along the lines of "I just service the system, I don't know anything about making sure the duct work is sized properly" (or something similar). I tried looking here for a professional from this site, but it looks like the closest one is well over an hour away.