There's been an effort in recent years to end the widespread use of R-22 and other ozone-depleting refrigerants in heating and cooling equipment. These refrigerants are being replaced by R410a and other environmentally friendly alternatives.
While selling A/C units with R-22 charged from the factory is now illegal, many manufacturers are taking advantage of a loophole permitting them to legally sell units without running afoul of the recent regulations.
What is a "Dry Charged" Unit?
A "dry charged" HVAC unit is simply a piece of heating and cooling equipment that's sold without refrigerant included. Instead of charging the unit at the factory, the manufacturer instead leaves the charging up to your HVAC technician. The vast majority of dry charge units sold by manufacturers are intended for use with R-22 refrigerant.
The whole idea behind a dry charge system is simple. Although current regulations forbid selling A/C and heat pump systems with hydrochlorofluorocarbon-based (HCFC) refrigerants like R-22, it's still legal for technicians to replenish current systems with said refrigerants. Having your technician charge up a brand-new HVAC system with R-22 is a clever way of getting around those regulations.
What's the Benefit?
Many homeowners believe that R-22 offers better cooling performance than newer refrigerant technologies like R410a. These homeowners may also own older heating and cooling equipment that currently uses R-22. During HVAC system replacement, the refrigerant from the old unit can simply be harvested from the old unit and swapped over to the new unit with few problems.
Should You Buy One?
That depends on your current heating and cooling circumstances. Unless you have an older HVAC unit that already uses R-22, you're probably better off buying a brand-new system that uses the latest in environmentally friendly refrigerants. Today's R410a-compatible A/C and heat pump systems are more energy-efficient and more effective at cooling than their R-22-based predecessors. As time goes on, these units will also be less expensive to purchase, install and operate than those using R-22.
Also keep in mind that R-22 itself is being phased out in gradual steps. With manufacture and importation of R-22 nearing a close, it'll become harder and more expensive to find supplies of R-22 in the coming years. As a result, running a HVAC system with R-22 will become progressively more expensive. If you purchased a new HVAC unit that uses R-22 today, you'll likely end up replacing it with a unit that uses R410a or similar refrigerant.
For more information about the various options for your HVAC installation, visit sites like http://www.alliedairheat.com.