Comparison Winzel Expert vs Marley MEnV 180

The diameter of the holes intended for connecting air ducts to the ventilation unit. The more performant the air ventilation unit, the more air the ducts must pass and the larger, usually, the mounting holes. For wall-mounted models (see above), this parameter determines the size of the channel that must be drilled into the wall to accommodate the unit.

Class of air purification, which corresponds to the supply and exhaust unit.

This parameter characterizes how well the unit is able to clean the air supplied to the room from dust and other microparticles. Most often it is specified according to the EN 779 standard, and the most common classes in ventilation units are as follows:

— G3. Marking G denotes coarse filters designed for rooms with low requirements for air purity and retaining particles with a size of 10 microns or more. In residential ventilation systems, such devices can only be used as pre-filters; additional equipment will be required for additional purification. Class G3 is the second most efficient coarse cleaning class, it means a filter that removes from the air 80 – 90% of the so-called synthetic dust (test dust on which filters are tested).

— G4. The most effective class of coarse filters (see above), which involves the removal of at least 90% of particles of 10 microns or more in size from the air.

— F5. Classes with index F correspond to fine cleaning, the effectiveness of which is assessed by the ability to remove particles from the air with a size of 1 µm. Such filters can already be used for post-purification of air in residential premises, including even hospital wards (without increased cleanliness requirements). F5 is...the lowest of these classes, suggesting an efficiency of removing such dust at the level of 40 – 60%.

— F6. Fine cleaning class (see above), removal from the air of 60 – 80% of particles with a size of 1 µm.

— F7. Fine cleaning class (see above), corresponding to the removal of 80 – 90% of dust from the air with a size of 1 µm.

— F8. Fine cleaning class (see above), providing the removal of 90 to 95% of dust from the air with a size of 1 µm and above.

— F9. The most efficient class of fine cleaning; the higher efficiency corresponds to the ultra-fine cleaning class H (see below). Class F9 achieves dust removal efficiency of 1 µm at 95% and above.

– H10 – H13. Classes H are used to mark filters of ultra-fine (absolute) purification (HEPA filters) capable of removing particles of the order of 0.1 - 0.3 microns in size from the air. Such filters are used in rooms with special requirements for air purity – laboratories, operating rooms, high-precision industries, etc. In filters corresponding to the H10 class, the efficiency of cleaning from the mentioned particles is 85%. H11 claims 95% absorption. And class H12 and H13 are the most efficient with particle retention of at least 99.95% and 99.99% respectively.

— Carbon filters. Created on the basis of activated carbon or other similar adsorbent. Effectively trap volatile molecules of various substances, thanks to which they perfectly eliminate odors. Carbon filters are subject to mandatory replacement after the resource is exhausted, since if the service life is exceeded, they themselves can become a source of harmful substances.

The lowest performance with which the supply-exhaust unit can operate.

For performance in general, see "Maximum air flow". Here we note that it makes sense to indicate the minimum flow only in cases where the amount of air passed can be regulated (see "Number of fan speeds"). And even then, for such models, this parameter is not always given.

The highest performance of the air ventilation unit; or, if the air flow control is not provided for in the design, the nominal capacity of the unit.

In this case, air flow refers to the amount of air that the unit can pass through itself per hour. The optimal air flow value for each room is calculated by the formula "room volume multiplied by the air exchange rate"; the air flow must not be lower than this indicator; otherwise, we cannot talk about effective ventilation. The volume is easy to calculate by multiplying the area of the room by the height of the ceilings, and the multiplicity indicates how many times per hour the air in the ventilated space should be updated. It depends on the type and purpose of the room: for example, a multiplicity of 1 is enough for a residential apartment, and at least 4 is required for a pool (there are special tables by which you can determine the multiplicity for each type of room). Thus, for example, for an apartment with a living area of 70 m², a ceiling height of 2.5 m and a kitchen of 9 m² (air exchange rate of at least 2), a duct of at least 70*2.5*1+9*2.5*2=220 m³ (excluding bathroom and toilet, they have their requirements for multiplicity).

It should be noted that a certain flow margin (about 10–15%) will not be superfluous, but it hardly makes sense to chase higher rates — after all, performance requires appropriate power, which, in turn, affects the dimensions, price and...energy consumption of the installation.

The noise level produced by the air ventilation unit in normal operation.

This parameter is indicated in decibels, while the decibel is a non-linear unit: for example, a 10 dB increase gives a 100 times increase in sound pressure level. Therefore, it is best to evaluate the actual noise level using special tables.

The quietest modern ventilation units produce about 27–30 dB — this is comparable to the ticking of a wall clock and allows you to use such equipment without restrictions even in residential premises (this noise does not exceed the relevant sanitary standards). 40dB is the daytime noise limit for residential areas, comparable to average speech volume. 55–60 dB — the norm for offices, corresponds to the level of loud speech or sound background on a secondary city street without heavy traffic. And in the loudest, they give out 75–80 dB, which is comparable to a loud scream or the noise of a truck engine. There are also more detailed comparison tables.

When choosing according to the noise level, it should be taken into account that the noise from the air movement through the ducts can be added to the noise of the ventilation unit itself. This is especially true for centralized systems (see "System"), where the length of the ducts can be significant.

Efficiency of the heat exchanger used in the heat exchanger of the supply and exhaust system (see "Features").

Efficiency is defined as the ratio of useful work to the energy expended. In this case, this parameter indicates how much heat taken from the exhaust air, the heat exchanger transfers to the supply air. The efficiency is calculated by the ratio between the temperature differences: you need to determine the difference between the outdoor air and the supply air after the heat exchanger, the difference between the outdoor and exhaust air, and divide the first number by the second. For example, if at an outside temperature of 0 °С, the temperature in the room is 25 °С, and the heat exchanger produces air with a temperature of 20 °С, then the efficiency of the heat exchanger will be (25 – 0)/(20 – 0)= 25/20 = 80%. Accordingly, knowing the efficiency, it is possible to estimate the temperature at the outlet of the heat exchanger: the temperature difference between the inside and outside must be multiplied by the efficiency and then the resulting number is added to the outside temperature. For example, for the same 80% at an outdoor temperature of -10 °C and an internal temperature of 20 °C, the inflow temperature after the heat exchanger will be (20 – -10)*0.8 + -10 = 30*0.8– 10 = 24 – 10 = 14 °C.

The higher the efficiency, the more heat will be returned to the room and the more savings on heating will be. At the same time, a highly efficient heat e...xchanger is usually expensive. Also note that the efficiency may vary slightly for certain values of the external and internal temperatures, while manufacturers tend to indicate the maximum value of this parameter — accordingly, in fact, it may turn out to be lower than the claimed one.

The presence of an EC fan(fans) in the design of the air handling unit.

This term refers to fans with synchronous brushless motors, also known as EC motors. Such motors are more advanced than traditional asynchronous ones: in particular, they provide very uniform rotation, allow precise control of speed, have high efficiency, and generate almost no heat (which is extremely important in the presence of a cooler, see "Features"), and also efficiently operate over a wide temperature range. In addition, the noise level of such motors is noticeably lower, and the service life is longer. The main disadvantage of EC fans is the traditionally high price.

The electrical power consumed by the supply and exhaust unit in normal operating mode (for models with adjustable performance — at maximum speed) can help determine the connection requirements for the unit and estimate the cost of operation in terms of electricity bills. It should be noted that for models with an electric reheater (see "Reheater type"), this refers only to the power of the ventilation system, while the power of the reheater is provided separately (see above). Therefore, the total energy consumption during full operation will correspond to the sum of these power values.

The power consumption can also be used to some extent to assess the unit's performance: "power-hungry" units usually provide a corresponding airflow.

The power in watts consumed by the supply and exhaust unit with an electric reheater in normal operating mode can provide an estimate of the unit's overall energy consumption. By knowing the approximate power consumption figures, you can assess the unit's total energy demand, determine the connection requirements, and estimate the operational costs in terms of electricity bills.