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One of the most popular types of climate control equipment are portable (portable, mobile) air conditioners. The demand for this product is quite large among our compatriots.
There are several reasons for this:
- The notorious housing problem. Many young families do not have their own living space, and somehow you need to cope with the summer heat. A portable air conditioner is a good enough solution in such a situation.
- Autonomy. Some models of mobile climate control equipment can operate from autonomous power sources. That is why most summer residents use such devices as an alternative to stationary «windows» or fans that everyone loves.
- Possibility of movement. Not every Russian family can afford to install a ducted air conditioning system or a multi-zone split system to create a favorable microclimate in every room in a city apartment. Portable air conditioners for the home can be moved as its inhabitants move. In other words: where people are, there it cools.
Varieties and principles of operation of portable air conditioners
There are several types of portable air conditioners, which differ both in design and in the principle of operation.
Condensing type portable device
Everything is simple here: such an air conditioner is a conventional monoblock with an evaporative and condensing heat exchanger, a compressor and a fan. Freon is used as a refrigerant. As a rule, this type of portable climate control equipment is produced in outdoor version. The main advantage of such installations is the absence of complex installation work. The disadvantages include: high noise level and exactingness in the removal of hot air.
Evaporative Type Portable Air Conditioner
Structurally, this device consists of a housing in which are installed: a heat exchange unit made of capillary-porous material with through channels for free air movement; heating elements; air flow fan; container for collecting water.
The principle of operation of this device is quite simple. Water enters the heat exchange unit, which passes through the pores of the material located inside. Through the through channels located throughout the volume of the heat exchange unit, air is supplied, which leads to the evaporation of water. Water takes heat from the air and gives it cold, which accompanies the evaporation process. To increase the rate of evaporation of water, a fan is provided in the design of such a device.
As a result: the air leaving the device has a lower temperature than the air entering the device. In addition to cooling, air masses are cleaned of dust and moistened. A distinctive feature of such air conditioners is the absence of any pipeline and the ability to work in the fan heater mode in the winter season. Using such a simple and autonomous device, you get a personal portable air conditioner for relatively little money.
Battery portable air conditioner
In fact, this device was invented for cooling cars, thanks to which its supply voltage is 12V, although this small device can operate from any 12 volt battery. Car mini air conditioner, enclosed in a small plastic case and does not require complex installation. According to the manufacturers, the principle of operation of such a device is similar to the operation of a conventional split system: The refrigerant circulates in the system and evaporates when heated, which makes heat exchange possible.
USB-powered handheld microconditioner
This device can hardly be called a representative of climate technology, although it also has the right to life. Its principle of operation is similar to the operation of an evaporative air conditioner: the sponge in the device plays the role of a heat exchange unit. Under the influence of a stream of air, the moisture from the sponge evaporates, which leads to a decrease in the temperature of the air stream. This device needs power only for the rotation of the built-in fan.
Manufacturers’ promises and reality
Floor-standing movable condensing-type appliances have a quite sane cooling capacity, suitable for most rooms with an area of 10-18 m2. The lines of such devices are produced by most manufacturers of high-quality climate equipment. Even companies from the Celestial Empire began to appear quite good models.
As for portable evaporative air conditioners, manufacturers unanimously claim that the air temperature in the room can drop by 4-6 ° C per hour, and the effect of their products can be compared to a breath of a breeze. In practice, the temperature did not drop in two hours, but if you sit in the zone of the air flow, you create a rather pleasant impression, which, in general, has nothing to do with cooling.
A portable air conditioner for a car also cannot effectively cool the interior of a car, and here’s why: in the closed space of a car interior, the heat received by the refrigerant has nowhere to go. With such work, the device will cool the air on the one hand, and heat it on the other hand, reducing the efficiency to zero. To solve this problem, heat from the passenger compartment must be removed by constructing an air duct. Then what kind of portability are we talking about?
A handheld portable USB air conditioner is best viewed as a gadget that is less efficient than a small fan. Although, as mentioned earlier, the creation of such a device can give impetus to the creation of a serious and effective device. But that is in the future, in the distant future.
There is another type of portable air conditioner that we have not touched on in our story. This is a real-life device, the effectiveness of which is proportional to the size. There is no refrigerant or evaporating water in the design of the device. Peltier thermoelectric elements are used as a cooling module.
Their principle of operation is as follows: if you apply current to the contacts of dissimilar materials of the module, then either heat is released or it is absorbed, depending on the polarity of the voltage. We will not talk about the reasons for what is happening (this is described on Wikipedia), it is better to consider how to make a do-it-yourself mini-air conditioner based on Peltier modules.
Air conditioner on Peltier elements
Let us make a reservation right away that the effect of such a device will be insignificant, since in order to cool the air in a limited space, it is necessary to solve the problem of heat removal outside it.
- The first thing to do is to organize the removal of heat from the heating side of the Peltier module. To do this, it is best to use a powerful heatsink with a cooler from a PC.
- Now it is necessary to remove cold air from the cooling side of the module. To do this, you can use the second cooler.
- The entire structure must be enclosed in a housing, which can be used as a PVC pipe of the required diameter.
- The last step is to connect the device to the power supply. A PSU from an old PC is perfect for this.
For greater efficiency of the installation, several Peltier elements can be used, interconnected by the cold side of one module to the hot side of another.