justakidsmom

first of all, I will assume that the asbestos is totally encapsulated and not crumbly/friable. I would get rid of it now. People will not buy a home with asbestos because of the safety/health issues.

I would not have a Goodman system.

If you want the best comfort, then go with two separate systems, one for each zone. Or look into the possibility of one system with zoning controls.

I will assume cooling is more important than heating for your area/climate.

I would look into Carrier/Bryant two stg HVAC along with their superior residential zoning controls. Start with authorized dealers and request load calculation for correct sizing.

IMO
Good Luck!

The ducting that's made of asbestos is a very short stretch, and is as old as the system,,, we think installed in 65 - so we have to get an abatement crew to get it out -- Out with everything old! We want to go with one system - 2 zones.

The Bryant does have the 2 stage but the Trane has 2 stage motors two, 1 for the 5 ton and a lower power for a 2.5 ton (if I understand this correctly), and the Ruud also has the 2 stage cooling.

How can we find out which one has better efficiency and will have the least amount of repair issues?

I recently did some research on what equipment to get because we needed to replace our HVAC. One thing I learned was that no mater what piece of equipment you research, you will find people who will say bad things about it. Case-in point, the above comment on Goodman. By contrast, I have a relative in the HVAC business and they say Goodman is good equipment and that the only thing wrong with it from their point of view is the technisions say it's difficult equipment to work on. Otherwise, they were the 1st company to offer 10 warrantees.

I also learned that many of the core parts (such as compressor) for everyone is made by the same manufacturer.

What I also learned was that what mattered more than WHAT equipment you got installed was WHO was installing it. Good equipment can quickly go bad when not properly installed. There's all sorts of short-cuts that can get a system up and running... but they will require work in a short order. There are all sorts of extra things that can be added to improve the live of equipment (example, something called a hard-start kit... without it the equipement will still work, but this kit will make the equipment not work as hard trying to start).

Some people on this site, who shall remain nameless but know who they are, are Trane-washed and have a bias against Goodman.

Hookoodooku posts reasonable thoughts.

Goodman/Amana has a lifetime replacement warranty on their 410A compressor, part-only, if it should fail. The warranty applies to the original homeowner. If the compressor fails, the entire condenser (outdoor unit) gets replaced. You would still have to pay for labor.

No other manufacturer has this warranty.

To the OP: You have to make sure that your original ductwork can handle 5 tons of cooling. Many older homes have undersized ducts. Even if the new system is the same size as the older system, the ducts may still be undersized. The sealing of the ducts and the size and number of returns is also critical. Proper zoning can be tricky so the contractor has to know what he is doing. Also, 2 stage systems work well for zoning applications.

Regardless of equipment mfr, you have to go with the contractor you feel will do the best job.

Take care.

I would bet the ductwork is no where near set up for a 5 ton system so it would need to be replaced.
I would steer clear of Goodman unless you were comparing the top of the line Goodman to at least middle of the road Carrier, Ruud, Trane or other brand. Goodman Tempstar and Heil tend to be noisier and just kind of 'klunky' than some other brands and it seems easier to get a fly by night installer.
I bought a home with a Tempstar and the installer was a moron. I spent probably 40 hours opening up return holes in the floor/wall cavaties, adding a return duct and sealing every connection with mastic and still had a system that you had to turn the tv up every time the blower came on. I found out later my 'installer' took a class in HVAC online!! My first winter in 2006 I had 400-500.00 electric bills in a 1,700sq ft home and after the duct fixes I dropped it to 250-300 of course part of that was adding a good outdoor sensing thermostat. I think my bills with this new RUUD system will stay in the low 200.00 range. The new system draws half the amperage of the old one in heat pump mode. I am also getting by with 10kw of heat strips instead of 20 just sealing everything up and getting the ducts right.

I don't think there would be anything wrong with a top of the line GOodman but you better be VERY cautious of the installer. The installer is the most important key to the equation.
I do not think anyone in here is 'tranewashed' its just speaking the truth overall a Rheem Ruud Carrier Trane American Std Bryant and many others are just overall better systems.

I would not personally get a bid for a tempstar or the like even if it was a rental house. I thought the same thing before this experience 'who cares as long as it blows hot and cold when its supposed to' but after my experience with a system that was louder than my old mobile home with the furnace in a hallway instead of in my basement. No Thanks!!

5 tons for a 2100 sq ' house. WOW. I bet your house is very noisey when that thing operates.
Why dont you go about it the right way????? not 1/2 way!!

get a manaul J load calculation done on the house before just swaping out equipment.you will get true accurate answers to what the house needs. and be surised how much better your system will perform.