Refrigerant R-410A Pressure Temperature Chart – R410A is an HFC and is commonly used in residential and light commercial HVAC equipment for air conditioners and heat pump systems. It widely replaces HCFC R-22 which was mandated by the Montreal Protocol to be phased out of production and use by 2020. R-410A differs a lot from R-22 in both chemical make-up and the tools needed to measure the pressures of R-410A. Since R-410A operates at higher pressure and a different type of oil is used than R-22 separate gauges should be used to obtain pressures. Cross contamination of the oils can cause serious issues between the two types of systems and it is highly recommended to use separate gauges for service providers. (more…)
How Much Refrigerant for the Air Conditioner Question: What amount of Freon would it take to service a unit that services a 1200 square foot residential house if it were completely depleted?
How Much Refrigerant for the Air Conditioner
Answer: We get questions like this a lot in our email and this is not easily answered especially when we are talking about charging an air conditioner or heat system. No matter how the system lost its charge of refrigerant (many people refer to it as Freon which is technically incorrect) there are many things you need to know before attempting to charge the air conditioner or heat pump with refrigerant (or Freon is you prefer). (more…)
HVAC Triple Evacuation – There is definitely some confusion among HVAC/R technicians about the proper methods of evacuation before introducing the refrigerant to the refrigeration circuit. Let me be clear from the start that my methods of evacuating a refrigeration circuit are based on experience, education and an official guide produced by the US Military and their specifications and proper procedures for evacuating a refrigeration system. It is the proper procedure on any US Navy ship or support ship that a refrigeration system that has been open to the environment be triple evacuated before the refrigerant is reintroduced to the refrigeration circuit. The purpose is to prevent future problems because of contaminants including moisture in the system. (more…)
Compressor Overheating Troubleshooting | Air Conditioner Repair
What you will learn from Compressor Overheating Troubleshooting article:
1) Avoiding the problem of compressor over-heating
2) how does compressor overheating effect the refrigeration system?
3) diagnosing compressor overheating
4) repairing the problem of compressor overheating and future prevention
5) lots of related links to help you learn
Compressor Overheating Troubleshooting | Air Conditioner Repair – There are some problems with air conditioner or heat pump compressors that can be avoided with proper maintenance. Other problems result in a mechanical or electrical problem with the systems that need to be resolved. Compressor overheating is an issue that can cause serious problems with your air conditioner or heat pump system. A compressor that overheats can still operate and provide cooling or heating but if the temperature inside the compressor rises too high then the oil in the compressor can break down and reduce the lubrication and cooling effect the oil has inside the compressor for proper and necessary lubrication. This leads to possible mechanical failure and other problems that will occur to the compressor and in the refrigeration system that results from compressor overheating. When the oil becomes overheated it changes chemically. Through a lack of lubricating and cooling it becomes like an acid when the oil overheats. This eats away at the windings and will cause compressor failure. (more…)
Evaporator Coils Dirty Ice On Air Conditioner – It was a very hot day and I got a ticket to respond to a call for no cooling. The customer said there was ice on the air conditioner. The heating and cooling service operator instructed the customer to turn the AC off so the ice could thaw before I got there to figure out the problem. It needs to be thawed before any AC troubleshooting can occur. There are two main causes why the evaporator coil will freeze and cause ice on the air conditioner. One is decreased or no air flow and the other is a low refrigerant charge.
Proper Refrigeration Piping Installation Practices – Installing a new air conditioning and heating system requires skill and knowledge of proper procedures in electrical wiring, controls wiring, and pipe work. On commercial projects a skilled electrician handles the electrical hook ups, a controls technician handles the control wiring, and a pipe fitter handles the pipe work including the refrigeration piping which can include chilled water and refrigeration pipe work. (more…)
Two-Stage Scroll Compressors
Two-Stage Scroll Compressors – For many years HVAC manufacturers used two compressors in their higher efficiency equipment to stage the air conditioner or heat pump for added efficiency. They would use a small compressor for the lighter loads or demands and then when the air conditioner or heat pump needed more demand the small compressor would shut down and the larger compressor would kick on to satisfy the demand. The HVAC controls would were often complicated and the equipment was difficult to troubleshoot when there was an air conditioner problem. There were all sorts of ways to accomplish staging including one manufacturer that would sell one whole unit that was actually two condensing units manufactured as one piece of equipment. The air handler for that condenser has a dual slab coil for each stage of the air conditioner. A two stage cooling thermostat would kick the second compressor when the demand called for additional cooling. Then new technology became available that changed how staging was done for higher efficiency models. (more…)
What is a Metering Device – Refrigeration Components
What you will learn from What is a Metering Device:
1) We will answer the question, “What is a metering device” by defining the various types of HVAC equipment that use different types of metering devices and why.
2) How the metering device is involved in the refrigeration cycle
3) A comprehensive list of metering devices defining the metering devices commonly used in HVAC
4) Lots of resource and related links to help you learn more about metering devices.
Depending on the type of HVAC air conditioning or heat pump system it is and the efficiency range of the system will depend on the type of metering device the system has installed by the HVAC manufacturer of the air conditioner or heat pump system. Lower efficiency HVAC air conditioner and heat pump models have fixed orifice types while higher efficiency systems have thermostatic expansion valves installed in the HVAC air conditioner or heat pump system. The thermostatic expansion valve is far more complex than the fixed orifice metering device as the thermostatic expansion valve metering device modulates the refrigerant flow based on the temperature of the refrigerant temperature in the evaporator coil. This allows a specific amount of refrigerant, based on demand, to be metered into the evaporator coil while the fixed orifice metering device allows the same amount of refrigerant to enter the enter the coil no matter the conditions or the demand. As the liquid refrigerant enters the metering device it changes temperature and pressure. A partial amount of the liquid refrigerant flashes into a refrigerant gas or vapor as it leaves the metering device and enters the evaporator coil.
Evaporator Coil for Heat Pumps & Air Conditioners
Evaporator Coil for Heat Pumps & Air Conditioners – the evaporator is responsible for absorbing heat into the coils and the refrigerant. The evaporator is an essential component of vapor compression refrigeration. This is usually done as result of passing air or water over the evaporator coil where a heat exchange process takes place. Heat leaves the air or water (whatever medium is used) and is absorbed into the coil and the liquid refrigerant. As more and more heat is absorbed by the evaporator coil and the refrigerant again changes state from a liquid to a refrigerant vapor. By the time the refrigerant leaves the evaporator coil the refrigerant should be all vapor and ready to be received again by the refrigeration compressor. (more…)
The Condenser for Air Conditioners and Heat Pumps
The condenser coil receives the high pressure high temperature refrigerant vapor from the compressor and immediately begins to remove heat from the refrigerant vapor. As the refrigerant vapor makes its way through the condenser coil more and more heat is removed and the refrigerant vapor changes state from a refrigerant vapor to a refrigerant liquid. While the liquid refrigerant changes temperatures from a higher temperature to a slightly lower temperature the pressure remains constant. As the refrigerant vapor leaves the condenser coil it makes it way to the metering device. (more…)