The core of a refrigeration system is the compressor that is designed to pump cool refrigerant gas from the evaporator into the condenser. Refrigeration compressors need to be properly maintained and require periodic inspection and testing.
A feature story in the Dec. 1, 2003, issue of The News dealt with air conditioning system diagnosis. That article focused on airflow problems. This article concentrates on refrigerant flow problems.
In our approach to humidity control for air conditioning systems, we must not overlook one very basic fact: If the evaporator coil is not cold enough, it cannot remove moisture, and it will stop removing moisture at its dewpoint temperature.
Manufacturers purposely design condenser and evaporator coils to work together in order to provide the best possible cooling for an application. So why would anyone consider replacing one coil and not the other? Why would anyone be tempted to oversize or undersize one component when the other isn’t designed for that capacity?
When facing a residential oil-fired furnace that is acting up, you want to get the situation under control as quickly as possible. A problem during the heating season will bring a call from an anxious and possibly agitated customer. The following are some of the most common issues that a service contractor addresses when troubleshooting an oil furnace, along with the possible cures.
Potential or “voltage” relays are used with single-phase capacitor-start/capacitor-run motors, which need relatively high starting torque. Their main function is to assist in starting the motor. Knowing the sequence of operation for this type of starting relay can help you diagnose, confirm, or rule out certain service problems.
There are four pieces to the refrigerant system diagnostic puzzle: suction pressure; high-side pressure; superheat; and subcooling. This article talks about subcooling.
The big push is on to replace R-22 unitary air conditioners and heat pumps, and it looks like the industry has really and truly decided that R-410A systems are “it.” This article offers an overview of some of the issues related to R-22 and -410A in the field: operating pressure differences, oil characteristics, and temperature glide.