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Direct replacement for 134a and other R12 substitutes!

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Instruction Sheet

R290 Charging Instructions for Central Air Conditioners

  • Determine the type of refrigerant used from the nameplate or owner’s manual
  • Determine the capacity of your system from the nameplate. It should state the capacity in ounces. Usually between 50 and 90.
  • If it uses R33, Enviro-safe R290 would be the proper replacement refrigerant. If it uses R12 or 134, then use our Industrial 12a.
  • If it is determined that the charge of refrigerant is low, adding additional product will usually return its cooling ability. Even though our Enviro-Safe Refrigerant is compatible with existing refrigerants, in some countries it is illegal to mix refrigerants.
  • Equipment needed would be at a minimum a R12/22 recharge hose attached to an appropriate can tap. A better choice would be to use a low side gauge in between to accurately measure the suction pressure.
  • To read system pressure, attach the hose/gauge to the low or cold side fitting. This will be the fitting near the larger pipe. Always check the pressure while the system is turned on and with the can tap shut (screwed in) or the can empty. The system will need to be running to draw the refrigerant from the can.
  • Usually with our R290 refrigerant, charging can be done by bringing the low side pressure up to a point of about 10 pounds below the outside air temperature. At 80 Degrees F. bring the pressure up to approximately 70 lbs. This works quite well up to about 85 degrees. Above that, we prefer the pressure to be 15 lbs below the outside temperature. For readings taken above 100 degrees the range may have to be even lower. If possible wait until it's not quite so hot.
  • To add, pierce the can by turning the tap clockwise several turns. Once the pin pierces the top, invert the can and back out the knob until refrigerant flows into the hose. You will feel the cold on the hose. The pressure will increase immediately, but you are only recording the can pressure and not true system pressure.
  • An alternative method would be to just add enough until it seems to cool properly. Do not overcharge. This only overworks your compressor and motor which could lead to premature failure.
  • With each of our 20 oz equivalent cans that you add, the low side pressure will increase. Sometimes only one can or less may be required or if it has all leaked out then it may take several.

These are only general instructions intended to help with charging. Remember some refrigerants are regulated differently in certain countries so always check you local laws governing the use or mixing of any product before using.

Caution: We are not responsible for any injury or damage that could occur from using our products in an illegal or inappropriate manner. Always use caution when using refrigerants and have the proper equipment before attempting to recharge unless you have knowledge of the procedure required. Always read the label on container before using. Our products are safe when used as directed.

*In the USA only, Enviro-Safe R290 is sold as a second generation replacement for R407c, R404a,and MO99. Outside the US, Enviro-Safe R290 is sold as an R22 Replacement. Not for use in R410a Systems.

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