Residential Trane Condenser Unit info and various other questions?

Greetings! This is my 1st post. Thanks in advance.
Trane model: TTD730B100A0
Serial: D06245542
Manufactured: 02/1989
I have tried to contact Trane for more info, but to no avail.
Here is a couple questions:
Should I upgrade?--I have had it serviced twice in 3 years(annual srvc). Both techs suggested I upgrade and increase the size. I live in a 1100 sq/ft 1959 rancher and just enclosed my carport to increase the living space.
My wife says she wants the house cooler. She sweats alot(grimmace).
What is the current tonnage? Trane model/serial# search on the Trane website doesn't find it.
What kind of energy savings can I look forward to with an upgrade?
My basement is not conditioned, but it is finished and I "live" down there. My man cave as my wife calls it. Should I upgrade to a split system? Should I use the old unit to cool the basement?
Does anyone know about geo-thermal cooling in Maryland and would that be worth it?
Thanks for your help!
Regards, Buffalo

That is a 2.5 ton unit. That's a lot of cooling for 1100 sq ft but if poorly insulated may take that much. That's likely an 8 SEER and minimum today is 13 SEER so there would be some savings. How much depends upon location and electric rate.

If going bigger, dealer needs to make sure furnace blower and duct system can handle it. We find most ducts are undersized for what is there let alone going bigger.

2.5 ton.
Have a couple contractors come out and do a load calc on your house and see what size you need.

Thanks guys! Not sure how to take Marge though. She has many angry posts. I just talked to one of my buddies and he will be out next week or the following to take a look. He is a srvc tech for LU486 here in Baltimore. Good guy. He has been doing this for 20 some years and has his masters. One of my instructors at school. He'll give me the straight dope on what's up. The problem is I live in the sticks and with the price of gas, it's a real son of a gun getting anyone out here.
Anywho, looking through some of the house papers, when my wife and I bought the house we had everything inspected and srvc'd. One of the notes that the HVAC tech wrote was that the ducts in the attic may be undersized and also if we were to increase the size of the fan and increase the amount of vents, it would help. Right now here in Maryland @ 1:57pm Saturday, it's 87F out and 75.6F inside. The wifey wants it 70F in the house. She is always too hot.
Regards,
BuffaloBrian

Your Trane is 19 years old. Thats a good life span for any brand.

well, when properly maintained, just about everything should last alot longer than most other things. Right? But, should I upgrade or justmodify the evap, or the fan, or the duct or the vents? I will be living in this house for the next 50 years or so. What would you do? I cant say that money is too tight, but its not an expense that I would like. Should I overhaul the whole system?
Regards,
Buffalo

I'd look into increasing the R value of the attic insulation. See if other areas of the house could be sealed better to lower the amount of fresh air coming in the house.(infiltration is a major cause of high humidity in the summer, and low humidity in the winter)
This will save you money both in heating and cooling, saving you far more then just getting a higher efficiency unit.
Then, in your case, have your friend check for duct leakage, both supply and return. This is another reason for poor performance and high humidity.

Then, if the old system still couldn't meet my needs.
I would find out what size I need to cool to 70°, then replace it, and alter/mediate the duct system as needed to meet the air flow.

any money you spend on a 20 yr old system is going to be a gamble at best. if you have increased the living space you just shortened the odds. pull the trigger and get a system that you can live with the next 12-15 yrs.

I was up in the attic and it appears there are some minor holes that I could tape up so I did. All of the duct is that 12" grey flex stuff. Should I go rigid?
Hey, o\another question...what happens to the old unit when it is replaced? Scrapped? If so, is the exchange price of the scrap built into the price of replacement or can I just scrap it myself?
Living in a rancher, I'm sure you may know, there is a central return in the hallway, what if I were to have returns put in in some of the other roms and maybe from the basement? I would just hate to spend 8 big ones on a new install when I, unlike my sweaty wife, feel the unit is fine. Changing the ductwork would be far cheaper than a whole new setup.
Regards,
Buffalo

As far as scraping the unit yourself, you have to take that up with your contractor.
Repairs air leaks in your duct system can help a lot.
Redoing the duct work may or may not get you better cooling.
You need a contractor to evaluate your duct system to determine that.

a larger unit is not a upgrade unless you need a larger unit if you dont need a larger unit it is a down grade and also i would get rid of the grey flex and go with a ductboard trunk line and short runs of flex all properly sized the grey owl flex can appear good on the outside but the plastic internal liner broken

Check on what the recyclers will take and what they pay, when I recycled the coils from both indoor and outdoor units I got **$, they would not take the cabinet metal... so when I took the cabinet metal to the local dump they charged me almost what the recyclers gave me for the copper. In fact it cost me when one considers the cost of gas and my time (being retired my time is very cheap). Just a thought.
o.d.a.t.
Santa Rich