Comparison Digital DAC-IN07CI 21 m² vs Midea MSHI-07HRIN1 21 m²

General type of air conditioner.

Nowadays, on the market you can mainly find split systems, multi split systems, portable devices. More rare options are window models and monoblocks. Here is a more detailed description of each of these options:

— Split system. The most popular type of modern air conditioner. Such models consist of two units — indoor and outdoor. The outdoor unit is responsible for heat exchange with the environment — it is through it that excess heat is discharged (or vice versa, external heat is taken into the room, when working for heating). The indoor units are installed in the room, the conditioned air comes from it. Both units are connected by pipes through which the coolant circulates. Air conditioners of this type are convenient, in particular, because the indoor unit can be installed almost anywhere in the room; and in some models, the indoor units have an unusual design (see below), which allows such devices to fit even into non-standard interiors. Also note that split systems can have almost any performance, among them there are models of both household and industrial levels, and the installation of such air conditioners is relatively simple. All this led to their popularity.

— Multi split system. A kind of split system (see above), in which there are several indoor ones for one outdoor...unit. This arrangement allows using one air conditioner to organize climate control in several rooms at once, while the installation of such a system is easier, and the cost is cheaper than using separate split systems.

— Portable. Air conditioners made as a single unit, designed for the possibility of frequent movement from place to place; in some models, wheels are even provided for this. For heat exchange with the external environment, such devices use air ducts that lead out of a window, doorway, ventilation shaft, etc. A mobile air conditioner can be a real salvation where it is not possible to install a stationary device: it does not require complex installation work, just figure out where to bring the duct pipe. In addition, such a unit can be useful in a situation where you need to cool several rooms in turn, and it is difficult or impossible to install a stationary air conditioner for this purpose.

— Window. Air conditioners made as a single unit, installed directly in the window opening — so that one side of the device is indoors, the other is outdoors. It is one of the first types of air conditioners, but, nowadays, it is considered obsolete and rare — mainly due to the complexity of installation and a very limited choice of installation locations. In addition, such an assembly inevitably covers part of the window, which in some cases is also a serious drawback.

— Monoblock. Stationary air conditioners in the form of a single unit with wall installation. Such a unit is located inside the room, on the wall facing the outside, and heat exchange is provided by air ducts passed through the wall, through which the outside air enters the heat exchanger and exits it. Such a design allows you to do without outdoor units, which is very convenient in some situations — for example, if an air conditioner is needed for a historical building or house in a strictly defined design that does not allow unnecessary "decorations" on the facade. On the other hand, monoblocks are expensive, and the possibilities for their installation are very limited.

The British Thermal Unit (BTU) is used to indicate the rated capacity of air conditioners in cooling mode. The parameter is indicated mainly for split and multi split systems with wall installation. Capacity is indicated in BTU per hour, while 1 BTU/h is equal to about 0.293 watts. The rated capacity of an air conditioner is often a multiple of 1000 BTU. The indicator determines how many thousand BTU/h the air conditioning equipment provides. For example, the marking "9 BTU" here means a unit for 9000 BTU/h or about 2600 watts of effective capacity.

The practical meaning of the capacity is that by BTU you can easily determine the recommended area of a standard room in square meters: just multiply the figure indicated in the characteristics by 3. So, for 9 BTU it will correspond to 9*3=27 m². Note that there is no strict relationship between BTU and watts in this list: for example, air conditioners with an effective capacity of 2360 to 2900 W fall into the same category of 9 BTU. In practice, even such an approximate ratio is enough to understand which air conditioner should be considered for cooling certain area.

The number of indoor units supplied in the kit.

Split and multi split systems are divided into outdoor and indoor units (see "Type"). And the number of indoor units in the kit depends on how many rooms the air conditioner can serve out of the box. However, this parameter is more of a reference than practically significant. So, in a complete set (see "In box") split systems are supplied with one indoor unit. And in the multi split system, a complete set is rare and usually includes two such units; it is assumed that for the organization of a more extensive system, it is more convenient to purchase an outdoor unit and separately purchase the required number of indoor ones for it. Separate indoor units of multi split systems are also sold one by one.

The power provided by the air conditioner in heating mode. It is indicated by the amount of thermal energy that the air conditioner can "pump" from the external environment into the room when operating in this mode. The most modest modern units have a heating capacity of 2 – 3 kW or even less, in the most performant it reaches 6 – 8 kW or more.

When evaluating this capacity, the same formulas are relevant that are used in calculating the power of traditional heating. So, for the full heating of an ordinary residential or office space (with ceilings of 2.5-3 m and normal thermal insulation), a thermal power of at least 100 W is required. There are more detailed calculation rules that allow you to calculate the necessary characteristics for other conditions. And if we are talking about a separately sold outdoor unit (see "In box"), then the meaning of this parameter is somewhat different. It indicates the maximum power of the indoor unit that can be connected to this outdoor unit to work in heating mode. For multi split systems, respectively, the total capacity of all indoor units is taken into account.

Recall that most air conditioners are not designed for use as full-fledged heating systems. However, such a unit can be a good addition to the main heating system. At the same time, air conditioners are less expensive than el...ectric heaters: the heater has an effective power equal to energy consumption, and the air conditioner consumes much less energy than it supplies to the heated room.

Also note that the unit BTU (more precisely, BTU/hour) can also be used to indicate the effective capacity (including in heating mode). 1 BTU (BTU/h) initially corresponds to 0.293 W, and the numbers in the characteristics of air conditioners correspond to thousands of BTU/h. For example, a 7 BTU air conditioner will produce an effective capacity of 7000 BTU/h, or about 2 kW. Such marking is convenient because BTU can easily determine the recommended area of a standard room (in m2): just multiply the figure indicated in the characteristics by 3. So, in our example, the power of 7 BTU will correspond to an area of 7*3=21 m2.

The amount of air that an air conditioner can pass through itself in an hour.

This parameter depends on the power and the overall level of the device, but there is no strict dependence here: models with the same effective capacity may differ in air circulation speed. In such cases, it is worth proceeding from the fact that a higher speed contributes to uniform cooling/heating of the air and reduces the time required to create a given microclimate; on the other hand, higher-performing air conditioners use more energy, are larger and/or cost more.

The maximum and minimum level of noise produced by the air conditioner during operation; for split and multi split systems (see "Type"), by default, it is indicated for the indoor unit, and the data for the outdoor unit can be specified in the notes.

The noise level is indicated in decibels; this is a non-linear unit, so it is easiest to evaluate this parameter using comparative tables — they can be found in special sources. Here we note that, according to sanitary standards, the maximum level of constant noise for residential premises is 40 dB during the day and 30 dB at night; for offices, this figure is 50 dB, and in industrial premises higher volume levels may be allowed. So it is worth choosing an air conditioner according to this indicator, taking into account where and how it is planned to use it.

As for specific numbers, among the quietest modern air conditioners, there are models with a minimum performance of 23 – 24 dB, 22 – 21 dB, and sometimes even 20 dB or less. However, units at 31 – 31 dB and 33 – 34 dB are not uncommon; such loudness, usually, does not create discomfort in the daytime, but at night it is no longer desirable. However, in some cases, a louder air conditioner may be the best choice: noise reduction affects the cost, sometimes quite noticeably, and if the device...is not planned to be turned on at night, you can not overpay for additional noise reduction.

Additional features provided by the device.

In addition to features directly related to the main purpose (such as inverter, night mode or emergency heating), modern air conditioners can also provide very specific functions — such as ionizer, fresh air intake, air air pollution detection motion sensor, vertical blinds drive etc. For ease of operation, a connection to a smartphone and/or an advanced I Feel remote control with a temperature sensor can be provided, and for ease of maintenance, self- self-cleaning and/or self-diagnosis. Here is a detailed description of these features:

— Inverter control. The presence of a compressor with inverter power control in the air conditioner. Models without an inverter have only two modes of operation — full power and off, and the set intensity of heating/cooling is provided by turning the compressor on and off for certain periods. In turn, the principle of inverter control is to smoothly change the compressor power, which avoids constant switching on and off. It provides several advantages: minimal wear, no power surges and unneces...sary load on the mains, as well as a comfortable (low and stable) noise level. The main disadvantage of inverter models is the rather high cost.

— Automode. A function that relieves the user of the need to manually control the parameters of the air conditioner. It is enough just to set the desired microclimate in the room. After that, the unit will independently monitor the current conditions and select the desired operating mode. Most often, this function provides temperature monitoring and automatic switching between cooling and heating but advanced models may provide more advanced features, such as humidity monitoring with automatic dehumidification or even humidification.

— Timer. A function that allows you to set the time for automatic shutdown of the air conditioner. Thanks to the timer, you can, for example, start the air conditioner before going to bed and fall asleep peacefully without worrying about turning off the device — it will turn itself off after a user-defined time. And in some models, the timer is part of the night mode (see below).

— Night mode. A function that allows you to use the air conditioner as comfortably as possible at night. There are two main features of this mode. First, the fan speed is set to a minimum, which reduces noise and avoids strong air currents that can disturb sleepers. Secondly, the temperature change occurs very slowly and smoothly — by a couple of degrees within two to three hours; this is considered optimal for sleep. Additionally, in the night mode, a timer can be provided that turns off the air conditioner after 7-8 hours.

— Auto restart. Automatic restoration of air conditioner settings after a power outage. Simply put, when power is restored, a device with this function will continue to operate in the same mode as before the power outage.

— Ionizer. A module that saturates the air passing through the air conditioner with ion-charged particles. Negatively charged ions give a feeling of freshness to the air, have a bactericidal effect, and are also considered beneficial to health in general.

— Fresh air intake. Ability to mix fresh air from outside with the air passed through the conditioner. Thus, models with this function not only change the temperature and humidity of the air but also additionally refresh it. On the other hand, mixing significantly complicates both the design of the air conditioner itself and its installation. Therefore, this function is rare, and mainly in models of the middle level and above.

— Air pollution sensor. A sensor that monitors the presence of smoke, dust and other contaminants in the air passing through the air conditioner. The use of such a sensor can be different: some models can independently start the ventilation mode when pollution is detected, in others the sensor is only responsible for automatic shutdown, and ventilation must be turned on manually. However, this function greatly facilitates the monitoring of air quality.

— Motion sensor. A sensor that monitors the presence of people in the room. Using the location of people in the room, the air conditioner can change the direction of the flow away from people, thereby protecting against drafts. If the presence of people is not detected, then the air conditioner may switch to low power consumption mode and work not at full capacity, maintaining a comfortable temperature, and depending on the implementation of this functionality, it may even turn off if there is no activity in the room for a long time. It helps to save energy and provides an additional guarantee in case the user forgets to turn off the air conditioner manually.

— Vertical blinds drive. Recall that in most models the air outlet has the form of a slot, equipped with two types of blinds — horizontal (usually one), along the length, and vertical, along the height. By default, the motor drive has only a horizontal blind: this allows you to change the direction of the airflow vertically, as well as close the duct during non-working hours. However, some modern air conditioners (mostly wall-mounted, see "Installation") also provide a vertical blinds drive — it allows you to turn them from side to side, changing the direction of the horizontal airflow. It significantly expands the possibilities for setting up the unit for the specifics of the situation.

— Emergency heating. A function found in air conditioners with heating (see "Operating modes"); is intended mainly for summer cottages and other similar places that can be left unattended for a long time during the cold season. When using standby heating, the air conditioner maintains a low positive temperature in the room (about +8..10 °С). It is enough to avoid freezing of walls and damage to communications, and at the same time, energy consumption is low.

— Self-cleaning. The mode of automatic cleaning of the internal parts of the air conditioner — usually due to intensive purging with air. It allows you to remove the accumulated dust inside and dry out excess moisture and also prevents the growth of harmful microorganisms. At the same time, self-cleaning does not eliminate the need for full manual cleaning or replacement of working elements in the air conditioner filters.

— Self-diagnosis. The ability to automatically detect malfunctions and errors in the operation of the air conditioner. The specific features of the operation of this function may be different: in some models, the “health” of the unit is constantly monitored or automatically checked at certain intervals, in others, such a procedure is only started manually. Usually, self-diagnostic systems can automatically fix minor problems that do not require external intervention. More serious problems are reported to the user by the device, for example, by an error code on the display.

— Control via smartphone. The ability to remotely control the air conditioner from a smartphone or other similar device, such as a tablet. Usually, for this, you need to install a special application on the device. Such control can be more convenient and intuitive than using the remote control — the application can provide various specific parameters and functions that are not available for the remote control (for example, the schedule of work by day of the week). In addition, through the application, you can monitor the operating parameters of the air conditioner in real time — the set temperature, speed, programme, etc. — and receive notifications of problems. And some models with this feature can even be connected to the Internet — and get access to air conditioning control from anywhere in the world where there is access to the World Wide Web. Connection with the control gadget can be carried out via Bluetooth or Wi-Fi, depending on the model. For some devices, this feature may require the use of an external Wi-Fi module (see below).

— I Feel (remote control with temperature sensor). The presence of a temperature sensor in the complete remote control. Usually, such a remote control also has a separate button, when pressed, the air conditioner measures the temperature at the location of the remote control, that is, near the user. It allows you to more accurately control the microclimate than when using a sensor on the indoor unit — the device estimates the temperature at the user's location, and not at the installation site of the indoor unit.

A small screen installed on the indoor unit of the air conditioner. Such a display usually has basic functionality and displays a limited set of characters - numbers, some letters, sometimes also individual graphic icons. However, even such a screen can display quite a variety of information: set temperature, operating mode, timer settings, filter status, error codes, etc. Thanks to this, control is more convenient and visual.

— Hidden display. When switched off, the hidden info display blends in with the surface design of the indoor unit of the air conditioner and remains invisible. In active mode, the characters on the screen are visible through a certain place in the texture and all the necessary information is displayed on the display. On most models, the screen can be turned off using the remote control, and this feature can often be set to automatically hide after a certain period of inactivity, which will be useful at night.

The lowest outdoor temperature at which the air conditioner can operate normally in heating mode.

Modern air conditioners with heating mode are quite cold-resistant appliances. Thus, models where this temperature limit exceeds 0 °C are rare. A lot of units, even quite inexpensive ones, have a minimum temperature allowed for heating in the range of -5 ... -10 °C or -11 ... -15 °C. Models with indicators of -16 ... -20 °C and -21 ... -25 °C, although much less, are still quite a few, and air conditioners capable of heating at -25 °C and below are very close in terms of capabilities to heat pumps.