Helpful Information
From our experience, we know that people vary greatly in there mechanical abilities. As such, this section presents all the essential services that every customer, whether you own a small home or a commercial building, should perform annually. So, be sure to read this section and follow the steps closely.
In addition, we try to incorporate the more advanced technical aspects of our industry so that, should you have the desire, you can try working on your heating or air conditioning units yourself. However, we want to emphasize maximum safety if you are going to attempt to work on your own equipment. We encourage you to call us if you have a question.
We present more information than you could ever want or need to become an expert, if you so choose.
There are 4 main components (5 if we include refrigerant) used in the refrigeration cycle:
There are also five thermal laws that all refrigeration systems depend on:
It is important to fully understand these concepts and components if you are going to be working on any refrigeration system. The main process of refrigeration relies mostly on heat transfers, but just how those transfers are accomplished is where it becomes intricate and, sometimes, downright confusing. We'll start with the compressor, which is the heart of any refrigeration cycle. The compressor serves two purposes, the first is to circulate the refrigerant and the second, of course, is to compress the refrigerant. This is important because the refrigerant leaves the compressor as a high-pressure, high-temperature, superheated vapor.
The vapor is then discharged to the condenser where another series of important processes occur. Perhaps the most obvious process is condensing. The high-pressure, high-temperature, superheated vapor is pushed through a large coil that's been optimized with aluminum fins for cooling. This is where one heat transfer occurs. Most importantly, the heat from your house is being dumped into the outside air or being converted to hot water for domestic use, whichever your house is setup for. Air or water cools the refrigeration to a lower temperature liquid and the refrigerant exits the condenser and enters a filter dryer. In the filter dryer, moisture and any particulates are removed by means of desiccants.
From here, the refrigerant is sent to the next component, which is the metering device. Different systems use different methods for metering the flow of refrigerant, but on residential units you will most likely find thermal expansion valves. The idea of a thermal expansion valve is to control the refrigerant flow into the evaporator while simultaneously controlling the superheat on the outlet of the evaporator. The metering is usually controlled by a temperature sensing bulb that opens or closes a power head on the thermal expansion valve depending on the temperature of the refrigerant. If the bulb senses a lower temperature the head will close and, subsequently, less refrigerant will flow into the evaporator. When the bulb senses higher temperatures, the head will open and allow more refrigerant to flow into the evaporator. On newer systems, we are seeing more and more electronically controlled thermal expansion, but the theory remains the same. Thermal expansion valves are generally used on higher efficient systems.
The next and last component, of course, is the evaporator. When the high-pressure liquid refrigerant leaves the metering device, it becomes a low-pressure, low-temperature saturated vapor. The refrigerant enters the evaporator where the next heat transfer takes place. The hot air from your home is forced over the outside of the cooler coil where the refrigerant is 'boiling off' inside. This allows for a higher absorption rate of heat to occur and the refrigerant will quickly become a dry vapor. After the evaporator, the refrigerant will not be able to do anything else until it is forced through the compressor once again and the cycle starts over.
I will not go into the refrigeration cycle here. This article will just explain the basics of how your house is cooled and heated.
Before I go into detail about how your air conditioning system works, let's first get some semantics out of the way. Air conditioning does not just mean cooling. It is the absolute control of temperature, humidity, cleanliness and movement of air. That means air conditioning encompasses both cooling and heating and dehumidification as well as many other important functions that control the air around you. Now, you might ask why it says Air Conditioning and Heating right in our logo; while it is redundant, the definition stated above is not widely known to the general public and we do need to effectively market ourselves! From now on, however, I'll refer to air conditioning simply as cooling (in a few lines we'll find out why this may be an even worse term to use!).
So how does your house become cool during those hot Long Island summers? The answer is that it doesn't. It simply becomes less hot, and, if your system was sized properly at the time it was installed, dehumidified to a point of comfort. You see the laws of thermodynamics state that heat exists in air at all temperatures. Essentially there is no 'cold' (in the technical sense), just different levels of hot. We humans seem to be most comfortable at 70 degrees, so the goal of a home cooling system is to remove enough heat from the inside of your home or office air to reach that temperature.
The process that occurs when your cooling system comes on is simply a series of heat transfers. The hot indoor air is being transferred to a cooler surface (heat always from a hot object to a cooler object) and, from there, being transferred to the outside air by means of another heat transfer. The cooler surface that removes the heat from your house in this case is the evaporator, which is inside the air handler. The other heat transfer occurs at the outside unit called the condenser. The heat from your house is normally dumped into the outside air, though sometimes it's transferred with water. Thus, making domestic hot water is also a possibility, by means of a desuperheater. The refrigeration cycle is covered more in depth in the 'Basic Refrigeration Cycle' article.
For the heat transfers to occur there needs to be an appropriate amount of air movement inside the house. Air movement is achieved by a large blower inside of the air handler. The blower pulls air in on one side of the air handler, the return side, and discharges it from the supply side. A properly engineered system will take into account that hot air rises and cold air falls, therefore proper grill placement is imperative.
Each system is designed to handle a certain amount of air flow and a certain amount of heat energy absorption or cooling. If any of these aspects is impeded the system will not work poorly or, perhaps, at all. This is why regular maintenance is so important. Dirty filters can cause the amount of air moving over the evaporator to be significantly reduced and the possibility for a frozen coil is greatly increased.
On Long Island, some cooling systems are also used as heating systems. These are called heat pumps. The usage of heat transfer is exactly the same in the winter. The only difference is that the entire system runs in reverse (except for the air movement). Heating a home relies on heat transfers just as much as cooling a home. If your home uses a heat pump, the evaporator is now the outside unit in the winter and the condensing actually occurs in the air handler. The heat from the system is coming from the outside air! That may seem counterintuitive when you consider just how cold it feels in the middle of winter when the outside air is 40 degrees, but remember heat exists in air at all temperatures. Although it feels cold to you outside, there is enough heat in the outside air for your system to keep you warm in your house.
If you'd like to learn more about how your cooling and heating systems work, please check out some more of our articles.
On Long Island, perhaps the biggest consideration you need to take into account is when it is cost effective to replace an older unit. The average life span of an air conditioning unit on Long Island is 10-15 years. If an 11 year old system fails and the cause is the compressor or another high price item, you may want to consider replacement.
You also need to be aware, however, that a phase out of R-22 refrigerants (the refrigerant used in most air conditioning systems) has begun and getting a replacement R-22 condenser is quite difficult now. Some manufacturers, like Trane, still make R-22 condensers, but they are largely disappearing. What this means to you is that any system you are likely to get will have to be the new R410 refrigerant. Unfortunately, R-22 and R-410A are not compatible, meaning the entire system will need to be replaced for an R-410A condenser to work properly with the air handler.
When to Repair your air conditioner:
When to Replace your air conditioner:
Explanation soon to come.
Explanation soon to come.
Explanation soon to come.
Explanation soon to come.
Request a service appointment today with one of our experienced technicians.