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-717 Ammonia Pressure Chart
Ammonia, also known as R-717, is one of the oldest refrigerants. It’s origins as a refrigerant can be traced all the way back to the 1800’s and it was one of the first refrigerants used in a variety of applications. It is also widely considered one of the most efficient refrigerants available. The downside though is that ammonia is toxic in small quantities and can be deadly when released in larger quantities.
When the first artificial refrigerants were invented in the 1930’s the world began to move away from the natural refrigerants including ammonia. These artificial refrigerants like R-12 and R-22 were becoming the refrigerant used in nearly every application. It wasn’t until the 1980’s and 1990’s, when these artificial refrigerants began to be phased out, that we saw natural refrigerants began to rise again.
In today’s world R-717 has made an amazing comeback. It can be found in varying ranges of applications. Because it is so efficient it is often used in very large applications such as meat packing/processing plants, refrigerated warehousing, and even ice rinks. Unfortunately, these large quantities of ammonia can also lead to disaster if a leak occurs. In some extreme cases deaths have occurred due to large ammonia refrigerant leaks. It is always best practice to maintenance and take proper care of your system to ensure that no leaks can occur and if they do that they are minimal.
Let’s take a look at our pressure chart on ammonia:
|Temp (F)||Temp (C)||Pressure (PSIG)|