A example of how profit has replaced quality, is the thickness of the copper used to build the coils/internal piping. In the field, we are told to run ACR grade copper between the outdoor unit and the indoor unit. ACR is a thick walled cooper. Basically it is plumbing type L with nitrogen in it. The nitrogen is for moisture reasons (I will explain in the piping chapter). The copper these manufactures use to build the unit, is so thin, it's scary.

  One characteristic I prefer in the outdoor unit, it has to have a coil I can see. Some brands cover their coil with a stamped piece of metal. It is too hard to clean (unless you unscrew every panel). I like a exposed coil when I am outside, watering the lawn. I hose off my condenser (outdoor unit) keeping it free of dirt and pollen. Something that would be impossible to do covered up. A visible coil for maintenance reasons is important. Here' s a little trick. The next time you clean the brake dust off your car rims, head over to your condenser and spray the wheel cleaner on the outdoor unit coil, wait 1 min, and GENTLY rinse it off. Be careful not to bend the fins and work your way across back and forth, and working downward at the same time. A clean coil will save on energy consumption.

  Another important factor is how LOUD the unit is. If your going to put the outdoor unit near a deck, or outside a window, you really don't want to hear it. So the location of the unit will also determine price, brand.

  If you are choosing a contractor, choose a contractor your comfortable with. Don't think the cheapest price is the best deal. Cutting corners only limits the life span of the unit.

Indoor Unit (Air handler, Furnace)

 Air handlers come in 2 pieces or 1 piece. The 2 piece air handlers are made up of a blower section and a coil section and easier to get into a attic. The 1 piece air handlers need allot of UMPH to get it up there. Be sure you get the matching air handler for the outdoor unit. I do not like mix matching brands (unless your replacing one component) and/or capacity (tonnage). Mixing up tonnage is a old trick, but should be avoided to properly remove humidity, and humidity = heat .

  Air handlers come in different forms. Up flow, down flow, horizontal and multi poise. Horizontal is what you see in a attic, or hanging from a ceiling. Down flow is a vertical standing unit, blowing the air downward, while pulling the air in the top.  Up flow another vertical standing unit, blows the air up, while pulling the air in the bottom, (usually seen in a basement).