There are only a handful of major HVAC manufacturers in the industry, but that is changing as the Asian made influences infiltrate the market.
The "American" companies are corporate holders of many sub-brands. For example:
Carrier owns and makes
- Carrier
- Bryant
- Payne
but they also own and make the ICP brands:
- Tempstar
- Air Quest
- Keep Rite
- Comfortmaker
- Heil
- ArcoAire
- Day and Night
- private labeled brands like some Kenmore, Watsco, etc
The same can be said for Trane; they own and make their sub-brands like American Stanard and Ameristar.
As does Rheem; it also makes Rudd.
I think the thing I find most laughably interesting is that many folks will swear by one brand, and dis another, and yet those brands are nearly always made in the same plants by the same people using the same parts.
When I worked at Ford, I once had a conversation with a person that swore his Mercury Sable was a better built car than my Ford Taurus. I can attest that is total garbage, mainly because I had walked down the assembly line in the Chicago assembly plant and saw Sables and Tasrus' (Tauruses? Taurii? LOL) coming down the line in succession, one right after the other. Also, at the Ford plant where I worked, we made the steering components for those cars, and there was zero distinction between a Ford and Mercury steering gear; they were the same part number! I never worked at GM, but I've had the same conversations with guys and gals who worked at GM; they laughed with me. People would swear a GMC truck is better than a Chevy; they both use the same major parts and go down the same line in Ft. Wayne, IN !!!
Same could be said when I worked in the HVAC manufacturing industry. I had someone once tell me that a Carrier was far better than a Bryant. I can attest with 100% certainty that those two brands went down the exact same assembly line, using the same parts (for equal BOM'd units), and were put together by the same people. Though I never worked at Trane, I know folks who did, and they say the same thing.
You can thank a combination of brand marketing and anecdotal (good or bad) experiences for most all of the bias in many product opinions today.
I would agree that much of the success or failure of your HVAC system is a function of the quality/skills of the installer. He/she has a lot of influence over how well the system is sized, and installed. And ducts are a very big influence which go completely ignored in system performance. A poor duct job can make the best HVAC system seem like junk, and vice versa.
Is a Carrier built product better than a Trane built product? I'm not convinced yes or no. They are both good makes of OEM stuff. In terms of engineering, Carrier and Trane pretty much lead the industry development and bring new tech to market. Other makers simply fall in line once the path is already cleared. I once had a conversation with a sub-component supplier that told me when he was at a competitors facility, their engineers simply asked him "Does Carrier use this part?" ... "Yes they do." ... "Well then it's good enough for us; we're not going to reinvent the wheel if they've already tested and approved the design." This is common in the industry; Carrier and Trane spend a lot of time designing and proving out components, and then other OEMs simply sit and wait. That drives up the costs at Carrier and Trane, and then saves their competitors the investment costs. So when you wonder why some brands (for example, Goodman) are cheaper, it's because they don't put as much investment into their products. I'm not saying they don't engineer their own units, but they do ride the coattails of other brands at times.
I've also seen Consumer Reports over many years say "this brand has better reliability than that brand", for units that come down the same assembly lines. So take that source with a grain of salt.
I always recommend folks who are shopping for HVAC systems pick a few competing brands from well established local dealer/installer companies. You want a brand name you recognize supported by a long-standing local group who can help service/maintain your system should something go wrong. Then cross your fingers and hope for the best.
Oh, and by the way, ALL the HVAC manufacturers use parts sourced from over seas; pretty much impossible to get away from that. China, Korea, etc all compete in the markets for capacitors, compressors, TXVs, ignitors, blower motors, wire harnesses, .... this list is nearly endless. About the only stuff in a major HVAC unit which is "American made" is often the steel and the insulation blankets and a few odds/ends. All the major sub-components are made elsewhere. Some units are made (assembled) in the US; many are Hencho in Mexico.