AC units must be level – Here’s why!


Installing an air conditioning unit can be daunting. There are many things to remember, or else you are might end up with a costly and hefty fan. Even if you have never installed one, I am sure you have heard contractors or builders state that what ever you do, keep the air conditioning unit level when you place or mount it. But why?

The majority of air conditioners contain compressors that run on oil. If the air conditioning unit is not level, the compressor’s motor cannot access the oil, and the motor will burn out or overheat. The compressor’s motor requires oil to lubricate the moving parts inside, and without the oil, the gears will run at high revolutions, building up heat and friction, ultimately wrecking the engine.

Air conditioning units come in many shapes and sizes. Depending on the performance, size, and model, they can range from affordable to bank-breaking expensive. Knowing how an air conditioner works and functions helps significantly in understanding why installing one can be complicated. Below we will discuss the different variants of air conditioners and which models are easier to install, their pros and cons, and which will fulfill your needs.

How does an air conditioner work?

Air conditioners work by cycling the hot or cool air in a room and cooling or heating it up. To achieve this, most air conditioners, as we established, use compressors and phase conversion. This process comes down to a fundamental physics law, where when you convert liquid to gas, it absorbs heat. We use air conditioning units, which repeat this process continuously. This is done by exploiting phase conversion by using refrigeration liquid or coolant in a closed system of coils.

Most air conditioners consist of the same fundamental parts, whose functions we will list and discuss below to better your overall understanding further.

  1. The evaporator or evaporator coils are the part of the air conditioner that receives the liquid refrigerant. Fans inside the air conditioner blow warm air over the refrigerant filled coils.  Inside the coils, the refrigerant absorbs the heat while changing from liquid to gas. When the refrigerant is converted to gas, it needs to turn back into liquid again to repeat the cooling process, which leads us to the next part of the air conditioner.
  2. The compressor, which is the main reason the air conditioning unit needs to level. The primary function of the compressor is to return the refrigerant gas back to liquid. The compressor does this by subjecting the gas to high amounts of pressure, which in turn generates large amounts of heat. The large amounts of heat need to be evacuated to the outdoors. The next part on our list facilitates this process, namely the condenser coils.
  3.  The condenser coils have two primary functions. One is to remove the extra heat generated by the compressor to the outdoors with another fan’s help. The second is to facilitate the refrigerant’s condensing back to liquid form so that the phase transition process may repeat itself.
  4. The last part on our list is known as an expansion valve or a thermal expansion valve. The function of this valve is simple yet cardinal to the whole process. The expansion valve controls the amount of refrigerant flow inside the evaporator using a temperature sensor. It thereby also regulates the amount of heat of the vapor that leaves the evaporator coils. The sensor is filled with a gas or liquid similar to the refrigerant inside the condenser coils. As the temperature rises, this substance causes the orifice or opening in the valve to open against the valve body’s spring pressure.

Different types of air conditioner

Most of us know about only a hand full of air conditioners, even though there are quite various models out there. They vary in size, power, and function. Below we will discuss the different types and which are more practical for everyday users and which are being used by big businesses like hotels and department stores. All these air conditioners share the same system of cooling, though if only in larger components. This means if any of the units mentioned below are installed on an unlevel surface, they will malfunction or be damaged.

  1. Central air conditioners are very common and are popular amongst homeowners as a cheaper alternative to separate units. Central air conditioning is comprised of a duct system that runs throughout a structure and a compressor unit that cools the air. The compressor unit is mounted outside the structure. When activated, the compressor cycles cold air into the duct system using a fan. In order to remove the warm air from the structure, a return system cycles the warm air to the outdoors. This type of air conditioning is excellent for big houses that need rooms cooled individually or all together.
  2. Window air conditioners are the most common of all air conditioning units. The name generally describes what the air conditioner looks like and how it works. These units are typically mounted close to or on to the windows of a structure. They are recognizable from the condensation that drains from them. The units’ exhaust systems push hot air out the back or the sides of the air conditioner. The refrigeration unit is aimed inward towards the structure’s interior, thereby cooling it. Window air conditioners are excellent for cooling one room, but they are not powerful enough to cool a whole structure.
  3. Through the wall air conditioners are very similar to window air conditioners. And as such, they function the same way. These types of air conditioners are usually also limited to a single unit per room. They are not powerful enough to cool a whole structure or house. Through the wall air conditioners are slightly more power effective than window air conditioners because they are installed in a hole in the wall that is then sealed airtight. They are also more practical as you will not sacrifice the use of a window when installing a through the wall air conditioner. Through the wall air conditioners are permanent, and cannot be moved, unlike window air conditioners.
  4. Portable air conditioners like window and through the wall air conditioners are freestanding units. The difference is that portable air conditioning units are mobile and can be moved from room to room, depending on their preference. This unit functions essentially the same way as a built-in unit, with the difference in that the exhaust is a giant hose or tube. The hose is connected to an airtight sealed duct, called a window kit, that fits within a window frame. This model type’s main drawback is the lack of power and noise generated by components in the compact system. This model is only effective in rooms that are under 500 square feet.
  5. Package terminal air conditioners are used in hotels, hospitals, and large apartment buildings. They consist of individual units built right underneath windows, a foot from the ground, inside the rooms. They are self-contained and function more or less the same as window air conditioners. The difference lies in how this unit reuses the condensate from the air on its own condenser coils, removing the need for a drainage pipe. The warm air is pushed through vents in the wall, removing the need for major construction.
  6. Ductless split system air conditioners are units that come in two parts. A condenser unit is installed outdoors, and a blower or compact evaporative unit is installed indoors. These units are connected with conduits that carry the refrigerant and power. Depending on their model, they can cool bigger rooms. However, their effectiveness is limited by the power of the condenser unit. Even these units, which are split in two, must be installed on a level surface to ensure that it functions properly and does not damage the condenser unit.
  7. Evaporative or swamp coolers use only water instead of refrigerant to cool the air. They are overall less efficient than units that use refrigerants, as they can only be used in drier climates. When used in humid climates, they produce an unpleasant sensation and are therefore not popular in tropical climates. These types of units are power efficient, though, and do not create any carbon dioxide emissions.

Final Thoughts

As stated at the beginning of this article, all air conditioning units need to be mounted or installed on a level surface. There is little to no exception for this rule, as gravity determines where the oil will be within the compressor. And without the oil to grease the gears inside the motor that runs the compressor, the air conditioning unit will fail to cool your house or break down in the worst scenario.

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