One of the very first steps when it comes to diagnosing your home air conditioner, refrigerator, or even your vehicle’s air conditioner is understanding the temperature and the current pressure that your system is operating at. Having these facts along with the saturation point, the subcool, and the superheat numbers for the refrigerant you are working on are essential when it comes to really understanding what is going wrong with your system.
After a visual inspection the very next step for the most seasoned technicians is pulling out their gauges and checking the pressure and temperature. It just becomes second nature after enough calls. I have heard stories of rookie techs calling some of the pros on their team for help on a system that they’re stuck on. It doesn’t matter what the situation is. It doesn’t matter if you’re in Miami or in Fargo. It will never fail that one of the first questions the pros ask the rookie is what is your subcool and what is your superheat? Having and understanding these numbers is key to figuring out what to do next.
But, these numbers won’t do you any good if you don’t know what refrigerant you are dealing with and what the refrigerant’s boiling point is at each pressure level. This article aims at providing you with just that information.
R-450A Solstice N13 Basic Info & PT Chart
The refrigerant known as R-450A is brought to you by the Honeywell corporation. This refrigerant falls under their new Hydrofluoroolefins (HFO) Solstice line of refrigerants. You may see R-450A referred to as N13 which is the official Honeywell brand name. As most of you know there has been a push to phase out HFC refrigerants such as R-134a, R-404A, R-410A across the United States. This push is due to the very high Global Warming Potential these refrigerants have.
R-450A was introduced as an alternative to the commonly used HFC R-134a. 134a has a GWP of over fourteen-hundred whereas the new 450A has a GWP of only six-hundred. That is a nearly sixty percent decrease in GWP saved by switching over to this new HFO refrigerant. It is also slightly more efficient then R-134a so users will end up seeing a savings on their energy bills as well. 450A is a Azerotropic blend of forty-two percent R-134a and fifty-eight percent of R-1234ze that uses POE oil for lubrication. While it is a mixture of HFCs and HFOs refrigerant it technically falls under the HFO classification. The good news here is that HFO refrigerants are classified as flammable or slightly flammable… but not the Solstice N13. It has an A1 safety rating from ASHRAE. That is the same safety rating that R-134a and all of the other common HFC refrigerants has. To me, that is a big selling point. There is no risk here unlike the risk you could find of when dealing with hydrocarbon or natural refrigerants. The only real thing to be concerned about here is that it still has a somewhat high GWP number… so it may be phased out in five or ten years.
This HFO refrigerant was designed to be used in a variety of medium temperature applications such as refrigerated transport, heat pumps, chillers, vending machines, super market cascade systems, and commercial/industrial refrigeration. It has been approved for use in many of these applications by the Environmental Protection Agency’s SNAP program as well. In fact, it was approved a few years ago now so you may have already run across it before. In most cases you’ll find it in only newer applications, but there is the possibility of a retrofit when it comes to vending machines.
Lastly, before I get to the PT chart I wanted to inform you that this refrigerant can actually be charged from either the liquid or the vapor phase. It is your choice. That is why in the table below I included PSIG for both liquid and vapor. If you have any questions on the table or if something appears to be incorrect PLEASE reach out to me and I will get the information updated just as soon as I can.
|Temp (F)||Temp (C)||Liquid Pressure (PSIG)||Vapor Pressure (PSIG)|
Thanks for reading,