Unfortunately, I don't know if this is a well matched American Standard system for my house, but this is what I have in mind:

1. AS Gold SI (Allegiance 13) 3-Ton Condenser
Model = 4A7A3036 (up to 14.5 SEER)
2. AS Silver XI (Freedom 80) Gas Furnace
High Efficiency, Single Stage, 80%, 63K BTU.
Model = AUD1B080A9H31B
3. AS Evap Coil Model = 4TXCB036BC3HCA
4. AS PerfectFit Air Cleaner 5" Filter
5. New lineset
6. Thermostat XL803

House Information for load calculation:
1. Single story 1430 sqft home in Los Angeles, built in 1952 (60 years old);
2. Foundation = raised with 30" crawl space
3. Insulation= R-30 Insulation in attic; no insulation on walls or floor
4. 13 double-pane windows throughout house; 3 single pane windows in front (16 windows total)
5. Dark brown cement tile roof
6. Exterior doors = 2 (old wood front door with top half of door with glass panes; and new aluminum back door with quarter window)
7. Floors are hardwood floors throughout house except for ceramic tile in kitchen and 2 bathrooms
8. Winter's lowest average is December at 46, but we see some nights in the low 30s during the winter. I like to keep the furnace at 68 in the winter.
9. Summer's highest average is August at 90, but we see a couple of days between 100 and 110 during the summer. I like to keep the ac at 76 in the summer.

IMO

I'll see what the next independent havoc place says about smaller furnace.

Can't understand why dealers want to oversize.

IMO

IMO

Do you think that the lack of wall/floor insulation makes a big difference in the recommendation to oversize?

Also, what about claim that R22 is colder than R-410A, so you need a bigger a/c compressor?

These were two reasons that I got from installers.

I revised my equipment requirements as you suggested and I'm having installer review my choices:

1. American Standard 3 Ton Condenser
Allegiance 13 / Gold SI / Up to 14.5 SEER depending on coil
Model = 4A7A3036

2. American Standard Gas Furnace 80%
Silver XI / Freedom 80
High Efficiency Blower. Single Stage. 3 Ton Blower; 47K BTU
Model = AUD1B060A9H31B

3. American Standard Evaporator Coil
Model = 4TXCB048BC3HCA (14 SEER with this compressor?)

4. American Standard PerfectFit Air Cleaner 5" Filter (optionaldepending on price)

5. New lineset = want new lines since replacing refrigerant from R22 to R-410A

6. Thermostat American Standard 803 or Honeywell 8321

7. Use existing flexible insulated ducts if they are working well.

8. Use existing registers/vents/returns if appropriate.

Any dealer that spouts that nonsense on R22 VS R-410 should be shown the door.

IMO

Today, I spoke with a 3rd independent dealer over the phone about the 3 ton system that I spec'ed out with Tiger's help. Again, this dealer is sticking to the 400 sqft per ton rule of thumb for a/c and is recommending a 3.5 or 4 ton system.

I told him that unless he does a Manual J calculation, I'm going with a 3-ton system. He's pricing out my selections and will e-mail me a quote.

I have another question. Isn't the 803 thermostat overkill for me? I have a single stage system with no humidifier and no dehumidifier. I only have 1 zone...the whole house. So, why would a 803 thermostat be good?

I don't have wall insulation, but entered information as if I had wall insulation because I'm going to install it soon.

I think this means 3-ton AC and 2-ton furnace?

I did use a higher outside summer temperature of 95 instead of the average 89. I also used a colder winter temperature of 38 instead of the 40.

Also, I used the standard inside temperatures (75 and 70) even though I like 78 for summer and 68 for winter and I'm comfortable with those.

I used a free web site: http://loadcalc.net/

The bottom line is that the R13 insulation in the walls for my 1430 sqft house reduces the load calculation by about 1/2 a ton on a/c and furnace. So, without wall insulation (but R25 attic insulation), my a/c is at 42K BTU (2.5 tons) and my furnace is at 36K BTU (3-tons).

I always like to congratulate homeowners who make the effort to perform a load calc. It is good information especially if you have a load calc to compare against the dealer.

A couple of things.

Trane/AmStd 803 stat will help you on humidity control in AC cooling. If humidity is not a concern for your climate, then forget about it and go for a quality stat like the 802 model or same HW VP 8320. Honeywell makes Trane stats, some are just rebranded, the high end mdls are proprietary.

I still would stick with the 3 ton AC condenser. Here is the sticky part though. You must have a three ton rated blower in your furnace for AC cooling. This is problematic because it is difficult to find a small BTU furnace with a 3 ton blower. I am not surprised at your load calc for heating.

I did a little research this morning and found a quality Rheem furnace with a 41 KBTU output and a three ton blower. It is a comparable model to the AmStd as it has the high eff x-13 blower. I am providing a link for your review. Still think the AmStd quoted would be fine. Certainly it is better than what you have and will save in operating costs.

What have dealers said about new lineset?

I do encourage you to consider a whole house pleated filter media cabinet. As long as you have good accessibility, changeout is easy and these filters last up to one year before filter needs replacing. I have Trane's Prerfect FIt media filter.

IMO

On the Trane/AmStd 803 stat, it looks like the price difference between the 802 and the 803 should only be about $20, so I'll just get the 803 since it offers additional functionality.

I'm good with using the AmStd Freedom 80 furnace at an effective 47K BTU.

Dealers are saying the lineset can be flushed, but I've asked to replace it. I rather not worry about mixing R-22 with R-410A. It looks easily accessible going through attic to the outside wall.

Close does not count.

IMO

I was able to get a quote for a well-matched Trane system for a lower price, but still too high for my taste.

* Trane XR13 Condenser, 3-Ton. Model = 4TTR3036D
* Trane XT80 Gas Furnace 80% AFUE, 60K BTU, 3-Ton High Efficiency Motor. Model = TDD1B060A9H31B
* Trane Coil 4TXCB048BC3HCA
* Trane Thermostat Model = XL803 (with humidity control)

ARI Ref = 3790536
Condenser = 4TTR3036D1
Coil = 4TXCB048BC3
Gas Furnace = XT80 TDD1B060A9H3
EER = 12.00
SEER = 14.00

This the price for the equipment and installation. No duct work, flush and reuse existing lineset. No rebates.

IMO

I was hoping the information would help someone else searching old posts on 3-ton systems.

I might start a new thread when I'm ready to ask about which of my final 3 a/c systems is a better buy based on equipment and price.

With the lineset, it's not so much R22 mixing with R410. The flushing with nitrogen(?) should take care of the gas component. The problem (as I see it) is debris and oil. The oil used by the two systems is incompatible.

It just sounds like it's safer to replace the lineset to avoid any potential issues.

I do understand that the lineset has to be the proper size as specified by the equipment manufacturer.

* Trane XR13 Condenser, 3-Ton. Model = 4TTR3036D
* Trane XT80 Gas Furnace 80% AFUE, 60K BTU, 3-Ton High Efficiency Motor. Model = TDD1B060A9H31B
* Trane Coil 4TXCB048BC3HCA
* Trane Thermostat Model = XL803 (with humidity control)

ARI Ref = 3790536
Condenser = 4TTR3036D1
Coil = 4TXCB048BC3
Gas Furnace = XT80 TDD1B060A9H3
EER = 12.00
SEER = 14.00

This includes flushing and re-using lineset, re-using ducts and registers, installation, no rebates, permits, and testing refrigerant levels as part of permit.