Recent Blog Posts
Opening a thermodynamics textbook, it is stated that the purpose of a refrigeration system is to maintain a cold region at a temperature below the temperature of its surroundings. This can be accomplished by employing a vapor compression refrigeration system. To understand how a vapor compression refrigeration system works, let’s start with a familiar substance…“water”. […]
When selecting a refrigerant, many factors influence the decision. It is important to remember that no refrigerant is perfect. One might have wonderful thermodynamic properties, but it is highly flammable. Another refrigerant may be safe for humans to handle, but it negatively impacts the environment. Selecting a refrigerant for a specific application involves careful consideration […]
ASHRAE Standard 34 is titled “Designation and Safety Classification of Refrigerants”. Among other things, this standard assigns each refrigerant a safety group classification based on the refrigerant’s flammability and toxicity. Refrigerants with low toxicity are given a rating of ‘Class A’, while refrigerants with higher toxicity are assigned ‘Class B’. According to Standard 34, refrigerants […]
What do the various refrigerant numbers mean? Believe it or not, there is a method to the madness. First of all, most refrigerants are “organic compounds,” which means they have one or more carbon-hydrogen or carbon-carbon bonds. The only series classified as “inorganic”, or lacking these bonds, is the 700-series, which includes ammonia, carbon dioxide, […]
When the refrigeration cycle was first developed, natural compounds were the only available refrigerants. Ammonia, carbon dioxide, and even sulfur dioxide were readily available and had useful thermodynamic properties. These refrigerants were great choices because they were easy to manufacture, readily available, and inexpensive to purchase. Unfortunately, due to the toxicity and flammability of these […]