I would consider proposal 3a based on price but listen to my comments below.

I think since the gas furnace is nearly 30 years old it should be replaced. You should get highest efficiency single stage upgrade in my opinion which is a 15 seer unit for your A/C. In your climate a heatpump may be able to provide the majority of heating with the gas furnace only helping during the extra cold weather (below 30). This upgrade shouldn't cost a fortune ($500 or so). Although your mother being older might night like the cooler air of the heatpump they do provide evenly heated rooms.

I would also advise against the builders grade outdoor units. These builders grade models are louder and don't have as nice of a cabinet. An upgraded model over the 13acx on quote 3a should only cost $200 more.

You should have the contractor look into duct issues is things aren't being heated correctly.

Don't oversize. I'm not sure you really need 5 tons.

Gestetner

Several questions.

1. Size of home
2. Size of Existing AC condenser to be replaced
3. Size of existing furnace along with blower rating size
4. Any existing problems/issues of old AC cooling adequately?

From your post, the ductwork system in this home needs a thorough inspection. The issue of poor airflow to upstairs needs to be investigated for suggestions to improve.

The furnace is about 27 yrs old, probably about 70-80% efficient. I would think about replacing. I notice dealers are all quoting 80% eff furnaces. The question is why? If there are no legitimate reason, I would want a two stg var speed model 95%+ efficiency. Now would be the right time to consider this.

I would not have the low end Lennox for my mother.

If you decide to postpone the furnace update, my choice would be proposal #1A. I don't like the furnace selection in 1B. If you are interested, I'll be glad to make several AmStd furnace selections.

I do not recommend a Heat pump for older homes with questionable insulation properties and because your mother probably won't like it.

IMO

She is almost definitely going to do the furnace now due to age. I don't know the ratings on the current furnace but I'm flying out today and can check. Given that she's likely to do both, that may be academic unless it magically turns out to be better than expected.

The contractors told her that the existing A/C is 5 tons. That's all I know about it other than it was installed in 1974 and its kaput.
She hates heat pumps with a passion. They have one at the beach in Delaware and they said it was freezing cold to them in the winter. There isn't any chance she could be convinced so lets scratch heatpumps off the list.

I would really appreciate better recommendation for the American Std furnace option. Any info on why its better would be helpful.

Lastly, she mentioned that the Costco/Lennox guy advised her that it was a lower end unit (as I'm talking to her about the comments above). He said he can quote her a better unit. Is there a consensus whether Am Std or Lennox is preferable in general? I saw in other threads that Am Std was usually listed as a top brand but didn't see Lennox mentioned as a top brand as often.

Gestetner

Accurate sizing of new HVAC is important both for comfort and operating cost. I would like you to verify exactly what you have size wise.

Ductwork needs to be inspected and problems of airflow to second floor should be addressed with recommendations to improve.

As far as furnaces, my first choice would be a full modulating furnace like AmStd XC95m or York/Luxaire with a high eff 15 SEER AC condenser.

Can you tell me about the size and design of home as well as insulation qualities?

I am opposed to Lennox as well as purchasing HVAC through a big box store like Costco.

Post back when time is available.

IMO

gestetner

second choice would be a good 2-3 stg var speed furnace like AmStd's XV95 or Carrier 58MVC mdl.

IMO

I was able to get info on the existing furnace from the data plate. It's a Carrier Model 58ss140-BC, Series 110, 167,000 BTU. The data plate said the blower is "157", whatever that means. The motor spec was 1/2 hp. Mfg date 1982. That's all I found on the furnace.

I found next to nothing on the a/c. The data plates outside are gone. I could see where it was but there was just rivets. A single, long rectangular unit outside. Like I said, vintage 1974, from the builder.

According to my mother, the quoting contractors guessed that the system was 4 or 5 tons. I don't know anything about who said what.

Turns out the Lennox/Costco guy was the only one to quote an upgraded unit. He also quoted:

Option #3B. $9,185. Platinum Package. A/C XC17-048 and 2 stage gas furnace SL280UH135 with variable speed and I-Comfort Communicating Controller.

I'm having a hard time getting her to look at the Am Std quote because they didn't quote her an upgraded unit option and their basic units were only about $1,000 cheaper than the upgraded Lennox units. ($9,145 vs $7,945).

About the house, I tried to describe it above. Built 1974. 3200 sq ft. and two stories. Attached garage. Full sun exposure--the property is not shaded. Brick exterior with not a whole heck of a lot of insulation. (I remember my parents being mad that the builder gipped them on the insulation.) High quality house though, expensive neighborhood. Stick framed over a full basement. Attic with pitched shingle roof. Colonial. Original single pane wood windows with storms windows, maybe a tad drafty.
After being widowed with 4 kids in 1978, she never had the money to remodel anything and everything is pretty much 1974. Anything else you want to know about the house, please ask. This is all I could think of.

Tigerdunes,

I've seen posts here and there about how it does not cost that much extra to bump up to a higher grade model within the same brand. The upgrade in the Lennox quote to better ac and furnace increased the quote by a few thousand dollars. Should the upgrade to the better Am Std units you recommended also cost a few thousand more? I'm trying to get an idea so I can follow up with that contractor (#1) and have a sense whether he's giving a good price or not for the upgraded units. (BTW, he sent my mother an email and told her that he would "up her warranty to 10 years" if that would get the deal done. Not sure of the specifics other than that.)

Thanks much.

The equipment cost often doesn't cost much more. There is typically no extra labor. Often the installer just wants to line his pockets. Often you can find independent installers that have less costs and overhead, and less people involved that want to make money. Sometimes you can get alot for your money with these contractors. Sometimes its worth calling them and asking them a general price over the phone for the equpment and efficiency's you want. (ex. 95% efficiency 2-stage gas furnace with highest eff. single stage A/C in 3.5 tons with new lineset and t-stat).

Some won't do it, others who are competitive will. Ofcourse they will confirm or deny those prices after examining the place where the install is occuring.

Gestetner

Just a couple of observations.

One of the least expensive and best bang for buck a homeowner can do both for comfort and operating costs is check and upgrade home's insulation properties. I would recommend that underfloor insulation for main floor be checked as well as attic insulation.

A telephone call for an HVAC quote is a waste of time. Not certain which is worse, the homeowner making the call or a questionable dealer willing to provide an answer.

It is foolish for a dealer like the Lennox dealer to quote an 80% eff furnace. What in the world are they thinking?

Current furnace is obviously grossly oversized which was quite typical for the time. Oil and nat gas were cheap. Who cared? More is not better. As stated before and can't be emphasized enough, ductwork in this house needs a thorough inspection both trunk lines and supplies/returns and in particular the air flow issues to top floor.

I like AmStd much better than Lennox and would never recommend purchasing HVAC through a big box store.

Let me know if I can help further.

IMO

Is $5700 good price for 15 seers American standard 2 ton unit?
I am in Nashville