I received an email from a homeowner in Wisconsin today that said this: “We recently had a 3 1/2-ton split system installed, but since its installation this unit has performed poorly. I was reviewing the service manual and see that the refrigerant in the unit is R-410A, and I know the installer added 5 lb. of R22 at time of installation. The service manual specifically states only R-410A should be used and as I understand, these two products work at very different pressures and use different lubricants. I came across an article you wrote about this today and I’m wondering what your opinion is as to why this unit has been doing such a poor job of cooling our home?”
Well, I know that to any of you who have ever attended a course on basic refrigeration, it sounds unbelievable that any HVACR installer or service technician would do such a stupid thing. However, I have come across many technicians and even company owners who believed they could improve a system’s performance by giving it a shot of another refrigerant. Yet, all this does is reduce the capacity and efficiency of the system and eventually leads to its failure. Why? Let’s take a look at those pressure differences.