There have been several threads here on TOTV concerning HVAC equipment specifically which company to use and what equipment to buy. While everyone has their own recommendations there is some technical information that's important to understand in additon to price.
What few HVAC companies will tell you is
why some of the more expensive options can potentially save you money on energy bills over the life of the system so you can make a more informed decision on what type of equipment to purchase based on your specific needs.
A TOTV member posted the following article in one of the other HVAC threads. I felt it was such a clear explanation that I wanted to re-post it so everyone could read it.
What is the Affinity Law – and what does it have to do with your HVAC system?
The article explains why variable speed fan and compressor systems such as the Carrier Infinity Greenspeed and the Trane Inverter systems use significantly less energy to run, whether you have a furnace or heatpump system vs a conventional single speed system. Most people also don't understand that this technology while recent, is used in all the mini-split systems that everyone is installing to cool their lanai's for example.
If you are considering replacing your system or will be thinking about it in the near future, this is a good read to better understand the difference between the cheapest single stage vs a more expensive variable speed HVAC system.