Charging with target superheat

This one covers how to charge the fixed orifice air conditioner once you have determined what the target superheat should be. This video is part of the heating and cooling series of training videos made to accompany my websites: and to pass on what I have learned in many years of service and repair. If you have suggestions or comments they are welcome.
If you are a homeowner looking to repair your own appliance, understand that the voltages can be lethal, the fuels are highly flammable and high pressures are used. Know your limits.

17 Replies to “Charging with target superheat”

  1. hi, my r22 suction saturated temp. is below 32F (around 20F). i tried to add some refrigerant to bring it up past 32F, but it won't go up. The low side pressure remains the same BUT the high side pressure rises. Do you think my filter drier is blocked? i see frost on the output of drier but not on the input side. i tapped at the drier and the low pressure drops to 0 on the low side. the unit has a piston . thanks.

  2. Technically it can be within plus or minus 3 of target superheat, so even if you were 3 over TSH. it should still be fine and not damage the unit right?

  3. Question, my evaporator is dripping water into my furnace. The level is good, filter is clean, just clean the condenser last week and it’s still dripping water. House is cooling well. Any suggestions?

  4. Gman how do you clean your gauges to used on different refrigerant without contaminating the line? Interested on buying a set but I want used it for multiple refrigerant if possible.

  5. You got confusing at 6:50 to 8 min. Weight on the scale was 15 oz(6 min). next time it was showed it was 3 oz (6:18 min) oz. Then you decided on 22 degrees of sub cooling due to a temp. change(7:02 min). Where was the change?

  6. hi, how do you find INDOOR superheat if there's no shrader port at the evap outlet? I see alot of A-coils that doesn't have a shrader port that you can hook your gauge up. thanks.

  7. Am a little lost on this one. A good exercise for us newbies would be making diagrams on what's connected where, which end is receiving and supplying pressure, and such.

  8. What do you do if the labels or worn off or missing. My friend needs her system checked out and I don't know where to start!!!

  9. Great video! The tip to remove refrigerant from the high pressure side when near SH target is awesome. Thank you

  10. Greetings Sir,
    Should we take system super heat or evaporator super heat as base for charging a fixed orifice system? Pls di tell.

  11. I know when you use gauges it is deferent refrigerant on each gauges    but can I use any refrigerant with digita gauges

  12. Well after watching all vids I could I felt confident enough to top off my 2 ton package unit with R22 using the superheat method. All is well now with one anomaly maybe someone can answer for me. The SLT goes from 66 to 48 to 66 again over and over. It has a fixed orifice with cap tubes to the evap. It took 2.8 lbs but blowing cold but I haven't seen a vid yet about this ping pong SLT. Anyone? Thanks.

  13. GMAN, you make the best videos, Thank You. Quick question: What specific formula do you use to calculate your target super heat? Other professionals have suggested a formula; 3 multiplied by return air wet bulb minus a constant number (80) minus the outdoor temperature measured at the condensing unit. Does this formula sound reasonable to you?

  14. what is the problem when the super-heat is jumping all over the place and will not hold steady

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