45yr old 5-ton unit - Does anything compare?
Sorry for the length, but grandpa has a history, I need valid opinions please.
I purchased my 2500sq ft single story ranch style (rectangle, porch on the front & back) home in 1990 under $100k. The house was built in 1962, everything in it was original and in great working condition including it's original heat & a/c. Rheem, 5-ton w/dual fans outside, 3/4 inch coolant pipes outside to inside, downdraft with 2-spd fan inside, Honeywell 3 relay control box, Honeywell thermostat.
I'm in Oklahoma, and the first summer, it wasn't handling the humidity, the service guy had a few years experience and replaced the thermostat with a programmable Honeywell that did the job and made it comfortable. He said he thought the 5-ton was a commercial unit and estimated replacing the entire unit for $6-$8k, in 1990.
The next 10yrs, 1yr average electric bill - $100/mo, replaced one outside fan motor and about every 3yrs, added just a squirt of freon. The next 5yrs, 1yr avg elec bill - $125/mo, replaced the other outside fan motor, one capcitor, the inside fan relay would stick on or off occasionally, due to vibrations in the fan squirrel cage causing the belt to wear out, my mechanical husband removed, disassembled, rebuilt, reinstalled it for quiet continual operation. The last 2yrs, 1yr avg elec bll - $150/mo, the inside 2-spd fan motor stopped and was rewired to work on 1-spd, the inside fan relay sticks more often, will soon need it's 3yr squirt of freon.
For 17yrs, every service guy called to work on it has said replacing the entire system would make a big difference on our electric bill, but with the few service calls these years, it wouldn't make enough difference to justify the cost and I know there's nothing that will live as long as this one. The young green service guys have no idea how to work on it cause they've never seen one older than them and always said we have to replace it cause they don't make parts for it anymore, untrue we've always found what was needed. The older service guys that do know how to work on it (I fear ours will retire soon), have been impressed and amazed that it still works and is relatively economical, most everything has increased in costs over 50% from 1990, they request to give a quote when it does finally quit.
We've decided we've pushed our luck long enough and grandpa will soon tire. What is out there comparable to grandpa, that will do the job, hope to last say 20yrs with little service calls, will hold or make a difference on electric cost, and doesn't cost as much as a new house? I just started calling for quotes, some want to hire an engineer to determine what is needed, others say we need a unit on each side of the house, others push heatpumps. I want another unit just like grandpa but if it was a commercial unit we probably can't afford the purchase even with a home loan, we're two working class people in our 50s. I need to know what brands have capable units, do I need a commercial unit, a good guesstimated cost for the entire installtion, should we use a standard HVAC service/sales company or some mechanical company, and anything else that will relieve the panic attacks I'm now feeling. Heeellllppppp! Thank you for your time.