R22 Superheat Subcooling Calculator Charging Chart

Good information for anyone working with HVAC

works great

I have to say I'm happy with this product because it does what it's supposed to, keeps you from having to carry a calculator while you are already dealing with temperature meters and pressure gauges, but the outdoor temperatures for Superheating is in 5 degree increments and the gauge pressure for Subcooling is in 10 PSIG increments, meaning you have to do some on the fly interpolation between the scales anyway. There is a lot of unused white space on the card, I don't understand why they didn't make the scales more granular. Maybe trying to save on ink? When trying to adjust a system by adding or recovering coolant, you aren't going to get to an exact degree of temperature or pound of gauge pressure anyway, systems just aren't deigned for that degree of accuracy, but I would like to start out with a more exact target to shoot for. Still, it's still a handy tool and sometimes its good to have the little reminders printed on the card on when to add and remove, because trying to coax a unit into compliance while hanging around for an hour or so in full sun when its 110 degrees in the shade (if there was any shade) is enough to make the best of us a bit confused and forgetful at times.

Superheat Subcooling Calculator is very easy to use and helps ensure you add the correct amount of freon to your system.

This chart is a good reference for working on a R-22 system, especially if you are new to the business. Remember, you must have a license to work with refrigerant.

instructions a little hard to follow. would be nice if manufacturer had an on-line video of how to use it.

I enjoy good quality tools, and this slide rule is one of them. Well worth the price. I use it in my business all the time.

I'm not an AC guy, but near as I can tell, it's accurate. And easy to use, even for me!