How do portable air conditioners work?
Tired of your noisy room fan that never truly cools the room on a hot summer night and only aids in evaporating the sweat on your skin? After all, it only eases your discomfort somewhat while you endure its many disadvantages. It messes with your hair and the paper on your desk, dries your eyes and it’s noisy, not to mention the obvious fact that a fan only moves the air around so when the air is hot, it only create a hot breeze. A fan doesn’t actually cool your room when the air is warm.
A fan is not a solution to staying cool during the summer but an air conditioner is. An AC unit, whether it’s a window air conditioner or a portable model (on wheels), are designed to cool the air, much like a refrigerator keeps your food cold. Putting a fan in a big box would not keep your food cold. The same is true for a fan in a living room don’t expect it to keep you cool, and yet for some reason, people continue to buy fans expecting it will keep them cool.
Yes, they are cheap, but fairly useless when the temperature rises. Personally, I feel that buying an air conditioner is one of the best investments for your home. There’s nothing worse than trying to sleep when it’s hot and sticky during the hottest nights of the year. I know, because for most of my youth I never had an air conditioner. You buy it once and it will last you for many years to come. Modern technology is a wonderful thing so why not use it to your advantage.
VIDEO | How Do Air Conditioners Work?
The Joys of Air Conditioning
Air conditioning provides us with a better quality of life in our own homes. We are all aware of their advantages because we are used to air conditioners comforting us in our offices and cars during hot and humid summer weather. We do not only use air conditioners to comfort ourselves, but also for decreasing heat stress on delicate equipment like computers and medical equipment. Grocery stores use them to reduce food spoilage. During spells of extreme weather, air conditioners help to keep elderly and other vulnerable people safe from heat-induced health stress.
Air conditioners improve indoor air quality and lower temperatures to acceptable levels. For many, the expense of having an air conditioner installed to cool the whole home, or a selected room is overbearing. Some of us, especially the elderly and singles, use only one room at a time and don’t feel a need to cool the whole house. A much better solution is to move the air conditioner where you need it, like your handy fan you use. It’s the reason that portable air conditioners entered the market many years ago. It reduces the expense of buying one and besides that, you can move it around. The main question to consider is whether or not a portable air conditioner is as effective as a window air conditioner. Which AC type is more suitable to your lifestyle and living arrangement?
VIDEO | How To Choose the Right Air Conditioner?
I’m about to prove to you that it is a worthwhile investment, that a good portable air conditioner can be as effective as any window air conditioner. But, before we dive into the virtues of portable air conditioners I want to indulge you in a discussion over the workings of all air conditioners. I believe that when you understand the technology somewhat you will better understand the differences between portable and installed air conditioners.
How Do Air Conditioners Work?
This is only a short basic introduction to how an air conditioner works. Just enough to help us understand and differentiate between the normal types and the portable air conditioners. They function on the same principles, but there are unique differences in how the technology is implemented. Although there are various air conditioner designs, we are all aware of the two most abundant house air conditioner types. I will only consider those basic units and ignore the central air conditioner with ducts to all rooms.
The most visible air conditioner used in homes must be the window type that fits in the space of a window removed to make space for it. This air conditioner has all the working components contained in one unit; it is an all-in-one design. Like all air conditioners, the window air conditioner has components that work on the inside of the house and some outside.
Measure your window and choose a model that will fit.
The inside components cool down the room temperature and the outside unit expel all the heat generated in doing so. The two components must be separated so you need a wall between the inside and outside. Therefore, the unit has its own built in insulated “wall” between the inside components and the outside components of the air conditioner. Most of the unit is outside the window and the shallower neat part is visible inside the room.
Another type of well-known air conditioner is the split-unit air conditioners. They have a neat installation inside the room and a second, larger unit outside. You can mount the inside unit against a wall, or it may be floor standing, or mounted to the ceiling. Two pipes connect the two units through the wall of the room. The split-unit air conditioner is so named because the cooling part components and the heated components are separated. Both types of fitted air conditioners are permanent fixtures that involves considerable installation costs.
Although they differ in design, they function the same and use the same air cooling principle. Both have an inside component that cools the room air. It is the part visible inside the room, normally fitted with controls, a grill, filter, recirculating fan and an evaporator. The fan sucks in room air and pushes it through the unit over the cold evaporator inside, to cool the air in the room. It introduces no outside air, removes none from the room, and it generates no heat inside the room.
Diagram : How Does A Mini-Split AC Work?
Outside the room is a unit containing a compressor, and the condenser coils, with another fan that circulates the outside air through the condenser. This unit generates a lot of warm air and expel it into the outside air. The warm air from the outside unit is not mixed with the room air. When the user chooses to let fresh air into the room, the unit takes it from another opening and mixes it with the room air.
All the cooling is done by the refrigeration components that form a closed loop. The compressor, a restrictor, an evaporator, a filter and the condenser are all interconnected with a pipe system to form a closed loop. This closed system has a refrigerant gas inside that the compressor circulates through the condenser, restrictor and the evaporator. The restrictor, mounted just before the evaporator restricts the flow of refrigerant, therefore the compressor forces the refrigerant through under pressure. Compressing the gas heats it, and the condenser and external fan removes that heat. When this high pressure gas escapes into the evaporator, it loses its pressure; it evaporates and cools the evaporator. From the other end of the evaporator the gas returns to the compressor through the filter to complete the loop.
It is important that we remember that the inside air conditioner component sucks air from the room, cools it and returns it to the room. The outside unit sucks in outside air, heat it and returns it to the outside. Nothing connects the two air circulation systems.
How Do Portable Air Conditioners Work?
Portable air conditioners differ from this in that all components are assembled in a single attractive unit on wheels. On the cooling side it still circulates air drawn in from the room through the evaporator to cool it and returns it to the room. This part of the portable air conditioner functions the same as any other air conditioner. It has the same user controls, filter, fan and evaporator. The portable air conditioner also has a divider between the cooling end and the warm end. This insulated separator plate ensures that the heated air is not mixed with the air in the room.
Because the components of the portable air conditioner that generate heat is now inside the unit, the heat it generates must be removed. The chosen solution exhausts the heated air through a large diameter hose to the outside through an opening at a window. Two designs are used, some units only have one hose connected to a window, another uses two hoses.
Both designs, the single and the dual hose portable air conditioners, make use of a fitting that fits to a partially open window. The design blanks off the opening in the window and provide a connection for the 5-inch hose or hoses. To adapt the fitting to most window types it can be expanded and contracted by sliding its two parts to fit a range of openings. Some designs offer a complete seal in the opening and some are less effective.
Single Hose vs Dual-Hose | Portable Air Conditioners
I already mentioned that single hose and dual-hose portable air conditioners are available. It immediately poses the question, why, what is the difference? When doing some research, you will also notice that there is not much difference in price between the two designs; I consider them equally priced. I expected the single hose designs to be lower priced, at least because only one hose is used.
The single-hose portable air conditioner has one hose to remove the heated air from the air conditioner through a special window fitting to the outside. To cool the gas in the condenser it sucks air from the room, pushes it through the condenser coils and to the outside through the hose. In doing so, it removes cool air from the inside of the room, heats it and vents it to the outside. So, it removes some of the air it cooled, making it less effective in cooling the room. The air removed from the room is replaced by air seeping in through crevices and openings. This air is warmer and further reduces the portable air conditioner’s efficiency.
The dual-hose portable air conditioner sucks in air from the outside through one hose and exhausts warm air to the outside through the second. Note that one hose sucks in air from outside and not from the room. The fan pushes it through the condenser where it’s heated and returned to the outside by the second hose. When you select the re-circulation mode on the controls it removes no air from the room. It also does not feed in air from the outside, therefore warm air is not mixed with the cool air. With the re-circulation mode selected the portable air conditioner functions at its best.
To my mind, the dual-hose model is the only sensible design. In re-circulation mode the dual-hose design is more efficient than the single hose design and saves you electricity. It is also more efficient in removing the heated air from the room so the back of the portable air conditioner remains cooler. Which adds to its efficiency and makes it a clear winner. It even makes it possible to mix some outside air with the air in the room, to create a positive pressure inside the room.
VIDEO | How to Install Dual-Hose AC | Whynter ARC-14SH
Do portable air conditioners work without a window?
It is possible to use the portable air conditioner without a window if you have some means of connecting the hoses to the outside air. You can adjust the window fitment to fit the opening of most standard windows. Generally, it blanks off less than 6 inches of the transparent space of the window. The impact is small, and the installation is quick and easy and adds to the portability of the machine. By using a window opening, the portable air conditioner remains portable, so it is the recommended method.
Portable Air Conditioner vs Window Air Conditioner
The main advantage is that you can move the portable air conditioner around to where you need it. It negates the need to have more than one air conditioner to cool different areas in the house, saving you money. Compared to a window air conditioner, one of its main advantages is a cost saving. Also, the window air conditioner uses a lot more of your window space and it is permanent. Another cost saving compared to any standard air conditioner is that you have no installation costs. The installation of standard air conditioners is done by professionals and almost doubles the cost of the unit.
Portable air conditioners are self-contained units; therefore, they sound similar to a window air conditioner. But, as with any air conditioner purchase, you should consider the decibel rating of the portable air conditioner when purchasing. A lot will depend on the internal sound damping and air flow design of the air conditioner. Most portable air conditioners rate between 48 dB and 60 dB. Ranging from the noise of falling rain to taking part in a normal conversation.
The portable air conditioner has the disadvantage that it takes up more floor space than the window air conditioner. It even uses more space than the size of the portable component on wheels. That’s because the hose that connects it to the window turns more space behind it into “used” space. The neatest installation is normally close to the window with the hose concealed behind it and as short as possible, reducing the space used.
The length of the hose should not be too much of a concern because an air conditioner works best when placed along a wall. In this case close to a window. How high the window opening is from the floor is the main consideration. Most units are sold with hoses of 60 inches long.
All air conditioners, including portable units, remove moisture from the air. To drain this water from the window air conditioner a drain hose is attached to the underside of the unit. Because you can move the portable air conditioner around, it is no longer possible, therefore they contain it in the machine. How you remove it from the portable air conditioner varies.
Some units, like EdgeStar and Koldfront portable air conditioners, have self-evaporative technology. It processes and evaporates the moisture and then exhausts it out the back of the unit. During high humidity spells water may collect in a reservoir inside the portable air conditioner. It is then necessary to manually empty the reservoir when it is full, or use a built-in draining system. Some portable air conditioners return some of this moisture to the room air. In modern systems the need to drain condensate is rare.
In climates with freezing winters, portable air conditioners have another advantage over the window type, you need not winterize it. You simply store it in the shed or store room until you need it again.
Power consumption for the same cooling power or BTU is similar between the two so it should not be a concern. All the portable air conditioners I researched use the standard 115 Volt / 60 Hertz household voltage.
What Size Portable AC Do I Need?
We rate air conditioners in British Thermal Units (BTUs) per hour. Understanding how you use that information to determine what size you need may be difficult. You want to avoid buying a unit that is too small and waste your money, nor do you need an overly large portable air conditioner. On the box, owner’s manual and probably the portable air conditioner itself they normally supply a room size estimate.
Although the BTU’s depend a lot on the room size, it is not an exact method to use room sizes only. We must also consider environmental factors for the number of BTUs required. Rooms with poor insulation or with heat-producing appliances will require an air conditioner with more BTUs.
The following air conditioner sizing chart offers guidelines that will aid in choosing an appropriately sized air conditioner for a standard room with 8-foot ceilings :
To get the best performance from your portable air conditioner you should ensure it only cools the required volume of air. Keep doors and windows that will introduce unwanted warm air to the room closed.
Will a portable air conditioner affect my health more than built-in units?
The short answer is no, it will be the same.
Research shows that people who use temperatures that are too low may experience chronic headaches and fatigue. It may also cause constant mucous membrane irritation and breathing difficulties. This leaves you more vulnerable to contracting colds, flu, and other illnesses. Many overindulge and cool the place to winter temperatures, it’s bad for you and wastes money. It will also have the effect that you become increasingly more intolerant of hot summer temperatures.
Another air conditioner related problem is that your skin loses moisture after long hours in air-conditioned environments. It’s better to aid your skin with a constant supply of moisturizers than to use a humidifier. The moisture your humidifier produces will force the air conditioner to extract more water from the air and waste your effort.
Something you must do when you use an air conditioner is to maintain it regularly. Many types of mold live inside filters and on the moist evaporators of air conditioners. Air conditioners can also circulate air-borne diseases. A potentially fatal infectious disease sometimes circulated in the air include Legionnaire’s disease that produces high fever and pneumonia.
Summary | Portable AC Units
The portable air conditioner has more advantages than disadvantages, is easy and quick to install and involve no installation costs. It must be within about 5-feet reach of a window, and the window must open in a way that will accommodate the adapter. Which limits where you can use it. If it does not pose a problem to you, I recommend that you consider a mobile air conditioner. It is even something you can take on a summer vacation to cool a mobile unit or a room in a vacation home.