A/C Furnace System replacement

Background: HVAC systems are original to the home built in 2002. FIrst floor system is 2Ton located in the basement. Second floor system is 2.5Ton in the attic.I have owned the home since 2017. The only issue we have had so far is that I needed to replace a starter capacitor on one of the compressors.

I am in Georgia so AC is the primary system. I looked at my electric costs; Winter - $166 for 6 months; Summer - $350 for 6 months. I had a contractor come in and give me an estimate for a replacement. He indicated that IF I installed a 14 SEER system I could cut my A/C operating costs by 50%. My math indicates that would be about $550/year [ (winter-summer)*50%*6months] . Replacement costs is not a trivial number.

Given the age, I am approaching end of life. I am wondering if I should just keep it running until there is a coolant leak. I can do most of the mechanical repairs myself (blower motor, venter, etc) so only have to deal with parts and not labor.

Appreciate any discussion on what I should consider when making a decision. Don't plan on being in the home forever. I am guessing 5 -8 years.

Not including basement: ~3900sq ft

 

50% savings going from 10 to 14 SEER? Doesn't sound realistic. https://www.seerenergysavings.com/

It is unlikely that both systems will fail in the next few years so better to put money aside in a savings account if one does need replaced.

 

They are claiming that the the efficiency drops over the years so the original system would be about a 7 SEER. No idea if that is realistic.

 

No.....that's not realistic.

A system installed would not be 7 SEER. Possibly 10-11 SEER. It doesn't lose that much efficiency with age. How is the insulation in the attic ? That's where the real money savings comes in.

A I have a Rheem 2-1/2 ton system that's just over 25 years old. I have no plans on upgrading it until it fails.

 

You may be able to reduce HVAC energy by 50%, but it won't be due to equipment efficiency alone. What did the contractor say about your ductwork design/condition? Duct sealing and insulation requirements are much more stringent today, and it wouldn't surprise me to see a significant savings by improving your ductwork.

AND if you replace, don't buy more tons than you now have: Your 18 year old equipment is not delivering the capacity it had when new, so if anything, smaller equipment is probably indicated. AND if you opt for equipment that's only available in even ton increments, go down not up - 2 tons to replace the 2-1/2.

 

The original system was a 10 SEER. Their claim was that efficiency dropped to 7 SEER over the 18 years. A year ago, I added blown insulation to attic an had them seal up the various openings. The did make a difference. The second floor went from not being able to keep up in the afternoon; 75 degree setpoint and the temperature would reach 78. This summer we never saw a temperature over 75.
Thank you for the advice on replacement. Seems to make sense. Even at 50% saving, it would be hard to justify replacement before system failure. The only system issue I have right now is that the blower motor in the attic makes a little more noise that it should. SPouse doesn't hear it but I do when the system turns.

 

He inspected the duct work but didn't comment on any issues.

 

Their claim is a lie to sell new equipment unless it's low on refrigerant, has really dirty coils or compressor valves are going bad. Stay away.
Operating efficiency can actually be measured, but doubt that most residential sales techs know how.

 

"He inspected the duct work but didn't comment on any issues." I suspect he had no clue. Find another contractor.