The requested URL /forums/index.php?topic=2924.0 was not found on this server. Non-Condensables In An A/C system Non-condensables are gases that will not condense into a liquid within the operating temperatures of the refrigeration system. Air and nitrogen are the most likely non-condensables we will see. Air can enter a refrigeration or A/C system when improper service and evacuation procedures are not followed or when you have had a leak on the low side. Nitrogen can enter the system in other ways. The new Dry R22 A/C units and most refrigeration equipment are shipped from the factory with a holding charge of dry nitrogen, not refrigerant. Once the refrigeration lines are connected, the service valves need to be opened and all of this nitrogen holding charge must be removed. The condensing unit should then be evacuated to 500 microns along with the lines and evaporator coil. When working with precharged equipment like R410A, care needs to be taken during leak checking procedures.

Some A/C manufactures require leak testing by pressurizing the system with nitrogen to 400 or even 500 PSI. These high pressures can potentially push nitrogen past the stop valves on the condensing unit and into the condensing unit refrigerant charge. To prevent this from happening, make sure to tighten down the stop valves completely before pressure testing. The stop valves may be sealed enough to hold the R410A in but not to keep the high pressure nitrogen out. Always use a nitrogen regulator with an accurate gauge to ensure you don’t over pressurize your system. Make sure to check the manufactures recommendations before pressure testing. If you do get nitrogen in the system, you will have high head pressure with high sub-cooling (cool liquid line) before you get the system fully charged. Suction pressure may be low and system performance will be poor. In most cases you will have high evaporator superheat and a high suction line temperature, but superheat may be normal. To confirm, shut the system off and let the pressures equalize.

Allow the condenser to cool to the outdoor air temperature. Check the pressure on the high side gauge and convert it to temperature using a PT chart. This saturated temperature should be within a couple degrees of outdoor air temperature. If this saturation temperature is any higher, you have nitrogen or non-condensables in the system. The entire charge should be removed into a clean and dry recovery cylinder. The system should be evacuated to 500 microns and recharged using new refrigerant. The old refrigerant can be reused after purging the nitrogen or non-condensables from the recovery cylinder.Refrigerants - Temperature and Pressure Charts Temperature and pressure chart for refrigerants R22, R410A, R12, R134A, R401A, R409A, R502, R404A, R507A, R408A and R402A Temperature and pressure charts for R22 R410A R12 R134A R401A R409A R502 R404A R507A R408A R402A  Refrigerants Temperature and Pressure Chart - Imperial Units   Refrigerants Temperature and Pressure Chart - SI Units

en: refrigerant temperature pressure chart R22, R410A, R12, R134A, R401A, R409A, R502, R404A, R507A, R408A, R402Aes: refrigerante diagrama presión temperatura R22, R410A, R12, R134A, R401A, R409A, R502, R404A, R507A, R408A, R402Ade: Kältemitteltemperatur Drucktabelle R22, R410A, R12, R134a, R401A, R409A, R502, R404A, R507A, R408A, R402Ajual ac portable sharpThis calculator requires the use of Javascript enabled and capable browsers. car air conditioning repair stoke on trentThis script determines the gas pressure based on temperature of R22 refrigerant. 5 ton hvac btuR22 or HCFC-22 is a single component HCFC refrigerant with low ozone depletion potential. It has long been used in a variety of air conditioning and refrigeration applications in a variety of markets, including appliance, construction, food processing, and supermarkets.

Production of R22 in the United States is scheduled for phased termination, beginning in 1995, with R-410A offered by Honeywell as a phase replacement. In 2015, production is planned to be no more than 10% of the manufactured amount in 1994; termination of production worldwide by 2030. Enter the temperature in either F or C degrees and the returned result is the alternate temperature and determined pressure in Barg and psig. Barg is the gauge read pressure. The term gauge signifies that the pressure has been read from a gauge that actually measures the difference between the pressure of the fluid or gas and the pressure of the atmosphere. Psig is equal to psis at sea level (14.7 psi). Psig is equal to psia � 14.7 at sea level. Psia is absolute pressure, which means it is gauge pressure + 14.7 psi. Now that I have indicated that, it relieves a lot of pressure...Air conditioning systems do more than just cool the air: They lower humidity and also remove dust, dirt and pollen by moving the air through filters and over the wet surface of the evaporator coils.

The easiest, and often most effective, maintenance step is to regularly change or clean your air filter. When filters become clogged with dirt, the system must work harder to do its job of keeping your passengers comfortable on the most sweltering of summer days. Depending on the amount of dust in the air, filters can become clogged in just a short period of time. Most late-model coaches have disposable filters that should be checked weekly and replaced when necessary. Earlier-model coaches have a cleanable screen that should be checked at routine intervals. A coach should never be operated without filters, which could lead to decreased system efficiency and a need for more frequent cleaning of the heat-exchanger coils. Likewise, keeping the air-conditioning unit free of debris and blockage is vital to maintaining proper airflow and efficient heat removal. Clean air can also reduce load and wear on the blower motors, extending their service life. But filters and debris-removal aren't the only story.

One of the most overlooked aspects of the air conditioning system is the freon itself and what it means to the air-conditioning system. A refrigerant can be any substance that will transfer heat from one location to another. In liquid form, a refrigerant will absorb heat when it evaporates; it is this conditional change that produces the cooling effect in the refrigeration process. When the vapor is changed back into a liquid through the process of condensation, heat is again moved, this time out of the freon. The word 'freon' is actually a trademarked name, but is often used to refer to any refrigerant gas used in a refrigeration process system. R134a and R22 are the two most common refrigerants used today, due to their respective boiling points and heat-carrying properties. The compressor compresses cool freon gas, causing it to become hot, high-pressure gaseous freon. This hot gas runs through a set of coils so it can dissipate its heat load into the surrounding air, and it condenses into a liquid.

The liquid freon then runs through an expansion valve that reduces the pressure suddenly, and in the process it becomes cold, low-pressure freon liquid. This cold liquid runs through coils that allow the freon to absorb heat from the air supplied by the blowers and evaporate back into a gaseous state. The now cooler air is then blown into the passenger compartment. The freon level is a major factor in maintaining not only the temperatures of the HVAC cycle, but also in maintaining system pressures. These operating pressures become one of our most valuable diagnostic tools for an AC system. Most coaches use receiver tanks as storage devices to separate the gaseous and liquid freon. The gaseous freon stays at the top, and the liquid freon settles to the bottom, where it is delivered to the thermal expansion valve. The thermal expansion valve is designed to meter liquid freon, and must receive only liquid freon. If the expansion valve doesn't meter correctly, it will flood or starve the evaporator.

If the expansion valve receives vapor instead of liquid from the receiver tank, as it would from a low refrigerant level, the evaporator will starve. Since there can be no vaporizing and heat transfer in the evaporator if that condition occurs, pressure levels are also affected. It will also cause the evaporator to work harder because the freon, already in a gaseous state, can't change states and absorb heat from the air. This puts a larger load on the system and impairs its capacity to cool. If the evaporator is flooded with liquid, the evaporator can't vaporize all of the refrigerant; in turn, liquid freon can escape into the compressor, where it can saturate the compressor and make it work harder. As the compressor attempts to compress the liquid freon (an impossibility), the buildup of heat and pressure can damage the compressor. Having too much freon in an air-conditioning system also creates problems. It increases the pressure and temperature, inside the system because the freon has less space to change states, which also reduces cooling efficiency.