When To Replace
In my neighborhood, There are many vehicles showing up to work on Heat Pumps and Air Conditioners. Many people have systems that are designed to be phased out, and the units may not be that old. There are several times that you should evaluate your decision on whether to pay for a major repair or continue to fix leaks.
Have you ever heard of an auto accident where the car was totaled? How was that decision made? The car value was depreciated because it likely had lost economic value anyway. Factored into the value would be reliability, usefulness, gas mileage and so forth. The market determined this.
With Indoor Air Quality, similar forces come into play You have an R-22 (refrigerant) unit that is inefficient when it is working correctly. It uses an environmentally blacklisted refrigerant. When it leaks it is polluting the atmosphere. Then it quits working, It has a bad compressor. That is a major repair. Now you have to decide whether to fix it or something else. We’re not talking a one or two hundred dollar repair. That would be like new tires on a car We’re talking putting a new engine in.here and the brakes and tires are worn , old battery and so on. Maybe they won’t have the parts at some point.
Not only is the compressor motor often the most costly part in the system, but it is not a simple "bolt-in" replacement. The service technician will:
- Confirm that the compressor has failed and needs replacement. Often the circuit breaker would blow because the compressor was shorted out or grounded.
- Identify the compressor model and capacity so that a proper replacement can be obtained
- Shut down the air conditioning system, including turning off electrical power
- Remove all refrigerant from the system. Modern procedures require that the refrigerant be captured rather than released to the environment in order to reduce environmental pollutants
- If the air conditioner system used a now-obsolete refrigerant such as R11 or R22, a the new compressor will be one designed to use a new, approved refrigerant and other changes may be needed to the system to accommodate this change, such as changes in thermal-expansion valves, coils, or other components. Not all components need replacement, however; ducts and blower assemblies, for example, are retained.
- The refrigerant lines are separated. and the old compressor is removed.
- The new compressor is installed in place in the compressor/condenser unit (usually all of this equipment is located outside).
- and its refrigerant lines are connected (brazed with silver solder) to the existing refrigerant lines
- .Nitrogen is pumped into lines during brazing.
- New coils or other controls may need to be cut out and replaced if the refrigerant is being changed too.(should be but if so would you not have replaced the unit?}
- A vacuum is pulled on the entire system both to evacuate all air from the refrigerant lines and compressor and to check for leaks in the system. Air contamination, if allowed to mix with the new refrigerant would change its operating characteristics and would prevent proper operation. A flush is used on burnouts
- Any water or moisture in the system is also removed and the technician may install a drier in the system to remove any trace moisture that remains behind after reassembly. A special HVAC compressor burnout dryer / filter may be installed on the refrigerant line(s) to provide extra debris and moisture and oil filtering capacity to protect the new equipment from debris clogging. Capillary tubes and TEVs as well as coils and compressors are vulnerable to damage from debris, stray oil, or water in the system.
- Refrigerant is added to the system at the proper charge amount. Residential air conditioner systems use a hermetically sealed compressor motor not designed to be reaired.The charge must be measured precisely (including temperature, pressure, and volume during charging) for the system to work properly. Both overcharging and under-charging refrigerants will lead to improper system operation.
- The air conditioning system, with its new compressor installed, will be re-started and checked for proper operation.
- Skip any of these steps and it could run and cool, but you could have problems down the road just like now..
- “The Techs got in and out fast and we were cool quick”. REALLY?
Future topic: Why not just replace the outside unit?
Portions of the above were inspired by www,Inspectapedia.com
