Carriers use copper coils--the aluminum outdoor coils are gone as far as I know (though Trane does still use them which is one of the pluses for Trane if you ask me, though you get varied opinions on this). Carrier and Trane are good brands but certainly not the only brands worth considering. York, Lennox, Rheem/Ruud are other brand ideas. BUT, you should focus on the contractor/installer first, brand second. The "best" brand can be installed poorly and the result will still be bad. You want a company that will A. do a good, thorough inspection of what you have/what you need, B. size the equipment properly and present you with multiple options, C. install the equipment using proper methods, and D. stand behind the work post-installation. Good luck. I'm also in Maryland but not an HVAC professional. If you are in Montgomery County, there are some companies I would recommend checking into around here.

kelly

there are three equally important parts for a homeowner to being satisfied when purchasing new HVAC.

1.correctly sized and quality HVAC equipment including thermostat, air filter, etc

2.a properly designed,sealed, sized, insulated ductwork system-if you have any hot/cold spots in home, now is the time to address.

3.the actual quality of install by dealer techs

now to specs on equipment that homeowner should look for in new HP system. obviously, it should qualify for fed govt tax credit up to $1500.

15 SEER,12.5 EER, 9 HSPF
full BTUs on both cooling and heating for rated size
best matching VS air handler
R-410a refrigerant(Puron)
new and correctly sized refrigerant lineset
scroll compressor preferred
electronic demand defrost preferred
staged backup heat strip
thermostat with "dehumidify on demand" feature

now to personal favorites

Trane XL15i or sister company Am Standard Heritage 15

Carrier Performance 15 "H" model or sister company model Bryant Preferred 15 "H" model

another brand worthy of consideration is Rheem/Rudd RPQL-JEZ series.

IMO
Good LucK!

The first thing make sure you have a good installer, because it is the most important thing in having a good system.
Carrier or Trane are both good equipment, just make sure you get the two stage compressor in it. As far as price for in two stage vs one stage is not that big of difference, but you get better, stronger and more efficient unit. I usually don't work with those particular brands, I work with Frigidaire and the difference in Firigidaire price between the 15 SEER and 16 SEER units is not that great, but huge differnce in compressors.
If you want something that is the best and most efficient in the industry right now check if anyone in your area installs Frigidaire Iq Drive.

Here is a link that might be useful: Brothers Heating home site

Many thanks to all for the good advice.

Tigerdunes, I have a couple of questions about the Rheem unit.
1. Off hand do you know if it has the dehumidify on demand feature?
2. As far as I can tell the Rheem electric backup isn't staged. Present 2 1/2 ton York unit is 208/240 11.3/15 KW. Do you think this is a concern?
3. I'm in a rancher (1450 sq ft)with the 2 1/2 ton as original equip. I finished 1/2 the basement (700sq ft) a good while ago and cut in 3 supplies, it seems the old unit was doing a sufficient job. Since I increased the load should I bump it up 1/2 ton while I'm at it? I see the Rheem airhandler is the same whether 2 1/2 or 3 ton.

Thanks again to all!

kelly

1.On DOD feature, you must have a VS air handler with the HP condenser plus the correct thermostat. For the Rheem HP system, Honeywell Vision Pro IAQ stat is the preferred choice.

2.You will need to ask Rheem dealer about the staged backup heat. An ideal staged module would be a 7.5KW/12.5KW, next possible 10KW/15KW. Again I suggest discussing with dealer. Keep in mind every 1KW of backup heat strip is apprx 3400 BTUs of heat. Managing heat strip use can help control your operating cost for winter heating. That is why I recommend staged heat strips regardless of brand of system.

3.if you are questioning size, ask dealer to perform a load calculation. Basements that are partially or below grade normally require very little BTUs in cooling and heating.If you don't have a return for the basement, it should be added. Air handlers are adjustable within a range for correct CFMs.

IMO
Good Luck!