All right so today we're going to be talking about closed versus, open refrigeration, which is something that we don't talk a lot about in the trade unless you're in school, and sometimes people will get it confused with an open compressor. An open compressor is completely different thing. That's when you have a motor driving a belt, that's driving the compressor and those we don't use very often nowadays, because they have a shaft seal. Shaft seal can tend to leak.

You may see some out there on equipment - that's quite a bit older, but you're generally not going to see that in modern systems. So if you look in the book and you look up open refrigeration, you may come upon an open compressor, but what i'm talking about is a refrigeration system that is actually not fully contained so quickly before we even get into open versus closed refrigeration. Let's talk about different types of energy containment systems, so when you think of an open system, an open system is a system in which energy can enter and leave so think of an open box and matter can also enter and leave so common open systems. Your home is an open system.

The energy can enter and leave through doors through windows through the glass through the walls to the ceiling, but then also matter itself can enter and leave. You can actually have air that infiltrates and exfiltrates in and out of the home. So traditional open system, then you have a closed system in a closed system. Energy can still enter and leave even if it's not a lot, but the matter cannot.

So if you think of a sealed jar, energy can enter and leave through the walls of the sealed jar via conduction. It can also enter and leave via radiation. You can actually get energy in through electromagnetic waves. We often call light in and out of the jar.

So that would be a traditional closed system and then you have what we call an insulated or isolated system, so think of a perfectly sealed yeti, cooler with uh infinite r value where the matter can't enter or leave and energy can't enter or leave it's sort of A theoretical situation, because it's not something that, from a practical standpoint, you're going to be able to accomplish so as you can control the energy moving in and out you're, also getting closer and closer to that truly isolated system. So it's important to know the three different types when we're working on a typical refrigeration system that we work on every day, an air conditioning system a refrigerator, a cooler, a freezer. Those are going to be what we call a closed system, because, obviously we need to move energy in and out. That's the whole point of the system that we're working on.

That's the whole point of refrigeration right, we're compressing the vapor refrigerant, which is then increasing the temperature. It's revealing that heat, so that we can then reject it to another medium. If you think of a typical home air conditioner, we do that all outside. We have your condenser coil, that's outside, so we run the refrigerant down the suction line, into the compressor where we then pack, those molecules together.

We decrease the volume inside that compressor. They come out at a much higher temperature. Now we can get that heat back out by transferring the heat to the outside air, that's sort of the typical setup that we use, and that is what we would call a closed system, because now it just circulates through we're not losing any matter. But if you go all the way back to the beginning of refrigeration, some of the most simple systems that existed, they were open systems.

A common example would be ice blocks. You have an old ice box. You know that your great great grandmother would use in order to store food. That ice would come from somewhere else.

As that ice is melting, it's changing state, and so it is using latent heat, but it is still an open system because, ultimately, that water ends up in the drain pan in the bottom of that ice box and is then removed. So open systems have an exchange of matter in and out of the system, whereas a closed system doesn't have that and you're just continually recycling. Another early type of technology that was still using compression refrigeration, but was an open system, was john gorey's original ice machine because what he was doing is he was compressing air and then decompressing air. In order to reject heat in and out, he wasn't doing a phase change, so it was only a single phase, refrigerant system, but it was still an open system because he didn't wasn't able to get it completely sealed in the systems that we have today.

So there was a lot of loss in and out of the system, but because he was using air wasn't a concern when you think about other types of open systems. You could literally take any refrigerant that we use today, and you could run it through an evaporator coil in its liquid state, and then you could just vent it now. That would be illegal and we're i'm not suggesting that you do that, but that would create a refrigeration effect, but you would be losing matter out of the system, which is what would make it open as we go into using more and more natural refrigerants refrigerants, like Co2 and propane and ammonia, and who knows what else, maybe we'll figure out how to more effectively use water and air as refrigerants? There is some advantage to having an open system, because now you don't have to reuse energy in order to change its state back on the other side. So the future of refrigerant systems may be more like john gorey's machine, where we're not concerned with keeping.

All of that refrigerant contained in the system, because the refrigerant, if it's okay, to vent, if it is air or is one of the major constituents of air, we don't have to worry about converting it back to a liquid and keeping it all self-contained another one that A lot of people don't fully understand, is even willis carrier's original machine used a spray of low temperature water in order to dehumidify and cool the air. Another example of an open system. So there's many many examples as we look through history of open refrigeration systems. Nowadays, we tend to think about closed systems whenever we think about refrigeration, because that's what we're used to working on.

But who knows what the future holds as far as open versus closed systems? And it's good for you to understand the difference between open, closed and insulated or isolated systems, thanks for watching our video, if you enjoyed it and got something out of it, if you wouldn't mind hitting the thumbs up button to like the video subscribe to the channel And click the notifications bell to be notified when new videos come out, hvac school is far more than a youtube channel. You can find out more by going to hvacrschool.com, which is our website and hub for all of our content, including tech tips, videos, podcasts and so much more. You can also subscribe to the podcast on any podcast app of your choosing. You can also join our facebook group if you want to weigh in on the conversation yourself thanks again for watching you.