Weighing Refrigerant In and Out

If you don't use a scale every time you add or remove refrigerant, I suggest you begin doing so immediately, if not sooner. Weighing in while charging is fairly obvious, and it's useful so you can keep track of what you are using and how much to charge a customer.

When you have a system that has just been repaired, it is a good practice to weigh in the charge to factory specs plus or minus adjustments for the line set if it is a split system. That is all pretty evident, but why would you weigh a charge out? There are many reasons, but one good example is that whenever you have a failed compressor, weighing out the charge can help indicate whether possible undercharge or overcharge may have contributed to the failure. With any significant failure on an older system, weighing out the refrigerant can indicate whether a leak is likely. When possible, on major failures, you could even weigh out the refrigerant at the time of diagnosis just to ensure that a leak or a compensatory overcharge may be at play.

Using refrigerant recovery to find a possible cause or even diagnose leaks on non-functional systems is a next-level diagnosis in my book. Use your scale.

Weigh in when adding charge.

Weigh out as a diagnostic aid and to ensure that you don't overfill your tank.

—Bryan

Related Tech Tips

The "Approach" Method of Charging and Condenser Efficiency
We have been discussing many methods for checking a refrigerant charge without connecting gauges over the last few months. This got me thinking about the “approach” method of charging that many Lennox systems require. The approach is simply how many degrees warmer the liquid line leaving the condenser is than the air entering the condenser. […]
Read more
Drain Cleaning Protocol
This article is primarily based on HVAC School’s “Drain Cleaning – More To It Than We Think,” hosted by Bryan Orr and featuring Corey Cruz and Mike Klokus. You can listen to that episode HERE. How hard could it be to clean a drain? The slime should just wash away if you flush the drain […]
Read more
How to Clean a Mitsubishi Mini-Split Blower Wheel
Ductless systems didn’t gain popularity in North America until relatively recently. However, it’s no surprise that they’re becoming quite common. They are quiet, efficient, and well worth the price in the long run. Highwall ductless systems have their downsides, though. When they get dirty, they can spread gunk beneath them and make a room smell […]
Read more

One response to “Weighing Refrigerant In and Out”

  1. I Agree you should weigh in the charge. Before scales we Used a charging cylinder. Also if you have an old scale it’s good practice to check how accurately your scale is. I have taken a can of soda to verify.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from