Looking for advise on a new HVAC/Air conditioning system

Hi there. New user here and have a question RE: Residential HVAC. I would really appreciate some advise, on which option to choose. Based on community rules, I am not putting prices on here. We live in Northern California - winter are mild, and summers have multiple days in the 100-110 Fahrenheit range every year.

Looking to replace an old (builder installed) Carrier system for a 1250 sq ft townhouse (3 bed/2 bath; single level property which is open on three sides and shares a wall with a neighbor on one side). Its a 1989 manufactured system, has been running well through summer and winter at least for the past year (we purchased the townhouse 18 months ago). While the system isn't really giving us any trouble, I saw a neighbor replace his earlier this year and it started me down this search. The current furnace is a 80000 BTU downflow system that sits in the garage. The current 2.5 ton air conditioner sits on the side of the townhouse.

I reached out to 3 companies for quotes. Two came recommended and have done work in our townhouse community. Third company through tie-in with Costco. All 3 recommended Lennox systems.

First guy told me that my 1989 Carrier system is still working OK (which is true, no issues with cooling or heating). He could clean up/replace sections of the ductwork, especially the return, and wait until it fails before I replace it. He also said he didn't have inventory from Lennox at this time due to COVID.

Second guy (Costco tie-in) gave me the following installation recommendation -

80% AFUE model
2 stage furnace - 45,000 BTU, 70,000 BTU.
Condenser - ML14XC1-030-230A
Furnace - SL280DF070XV36A
Cond. coil - 2.5 Ton
Filter - 25 x 14 x 1

Third guy spent the least amount of time with me (5-10 minutes), but gave me the most detailed quote. The third guy also told me that 1989 system is 60% efficient (not sure what it means, but he suggested 40cents of every $ is going up through the chimney). Based on his feedback, its a no brainer to replace it and will save me money on both heating and cooling. He priced 3 options for me - low, mid, high pricing.

Option 1 (low)


Full system replacement. Removal of existing equipment and debris from premises. Install Lennox 80% single stage furnace and 14 seer single stage air conditioner with matching evaporator coil down flow in garage. Safety float
switch on evaporator coil. Bubble wrap return duct and plenum. Install nest pro thermostat. Dfa box for easier filter access. Reconnect exhaust flue pipe and new gas shut off valve. Connect to existing copper line set, add filter line dryer, nitrogen pressure test, vacuum pump and braze copper connections. R410a refrigerant charged to manufacturers specifications. Ac anti vibration pad and service disconnect with fuses. Run test and start up. Permits and title 24 testing included with job.

ML180/ML14 2.5-Ton
Package Downflow
ML180 Gas Furnace
ML14 14-SEER Air Conditioner
Matching Evaporator Coil
White Rodgers Programmable Thermostat
Permit Cost and HERS Testing included
Labor Warranty -3 Year
Parts Warranty -10 Year
HeatExchanger -20 Year
Compressor -10 Year

Option 2 (mid)

Full system replacement. Removal of existing equipment and debris from premises. Install Lennox 80% two stage variable speed furnace and 16 seer single stage air conditioner with matching evaporator coil down flow in garage. Safety float switch on evaporator coil. Bubble wrap return duct and plenum. Install nest pro thermostat. Dfa box for easier filter access. Reconnect exhaust flue pipe and new gas shut off valve. Connect to existing copper line set, add filter line dryer, nitrogen pressure test, vacuum pump and braze copper connections. R410a refrigerant charged to manufacturers specifications. Ac anti vibration pad and service disconnect with fuses. Run test and start up. Permits and title 24 testing included with job.

SL280DF070V36A
(78W77)
*The quietest furnace in its class
*Two-stage heating operation
High-efficiency Variable Speed blower
*80% AFUE
*SilentComfort Technology
*Duralok Heat Exchanger
*SureLight Ignition
*Labor Warranty -10 Year
Parts Warranty -10 Year Manufacturer Warranty
Heat Exchanger -20 Year Manufacturer Warranty

LennoxSL280V
Upflow/Downflow 3-Ton
(A Cabinet)
(16F70/16F58)
* ETL lab tested 1% Horizontal A-Coil air leakage
* UV light knock-outs for easy installation.
* Microban® additive inhibits the growth of mold and mildew on the drain pan
* Coils are air pressure tested, Helium leak tested, sealed and charged with dry air
* Parts Warranty -10-year Manufacturer Warranty
* Labor Warranty -10-year Labor Warranty

EL16XC1-030 (13H77 + X1809)
*High-efficiency air conditioner
*Up to 17.90-SEER
*Quantum Coil Technology
*Precision balanced, direct-drive fan for consistent comfort
*Sound levels as low as 71db
*SmartHinge louvered coil protection for easy coil cleaning
*PermaGuard unit base resists corrosion
*Labor Warranty -10 Year Labor Warranty
Parts Warranty -10 Year Limited Manufacturer Warranty
Compressor -10-Year Limited Manufacturer Warranty

Option 3 - High


Full system replacement. Removal of existing equipment and debris from premises. Install Lennox 96% two stage variable speed furnace and 16 seer single stage air conditioner with matching evaporator coil down flow in garage. Safety float switch on evaporator coil. Bubble wrap return duct and plenum. Install nest pro thermostat. Dfa box for easier filter access. Run exhaust flue pipe with side wall termination kit and new gas shut off valve. Connect to existing copper line set, add filter line dryer, nitrogen pressure test, vacuum pump and braze copper connections. R410a refrigerant charged to manufacturers specifications. Ac anti vibration pad and service disconnect with fuses. Run test and start up. Permits and title 24 testing included with job.

EL296DF070XV48B (62W96)
*Two-stage furnace with Constant-Torque Power Saver™ technology
*Duralok Plus heat exchanger
*Fully insulated blower compartment for Quiet operation
*SureLight Silicon Nitride Ignitor
*Labor Warranty -10 Year Labor Warranty
Parts Warranty -10 Year Manufacturer Warranty
Heat Exchanger - Lifetime Manufacturer Warranty

Lennox EL296V
Upflow/Downflow 3-Ton
(B Cabinet)
(16F71/16F59)
* ETL lab tested 1% Horizontal A-Coil air leakage
* UV lightknock-outs for easy installation.
* Microban® additiveinhibits the growth of mold and mildew on the drain pan
* Coils areair pressuretested, Helium leak tested, sealed and charged with dry air
* Parts Warranty -10-year Manufacturer Warranty
* Labor Warranty -10-year Labor Warranty

EL16XC1-030 (13H77 + X1809)
*High-efficiency air conditioner
*Up to 17.90-SEER
*Quantum Coil Technology
*Precision balanced, direct-drivefan for consistent comfort
*Sound levels as low as 71db
*SmartHingelouvered coil protection for easy coil cleaning
*PermaGuard unit baseresists corrosion
*Labor Warranty -10 Year Labor Warranty
Parts Warranty -10 Year Limited Manufacturer Warranty
Compressor -10-Year Limited Manufacturer Warranty


Thanks so much for any assistance you can offer.

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