It is unpleasant when you enter the room, and there it smells unpleasant. Worse, if it happens in the toilet or bathroom. People are puzzled how to choose a fan for the bathroom and toilet. For obvious reasons, around-the-clock operation of the device is not required, silence conditions are violated. Technical characteristics of the fans are examined for the presence of a built-in timer.
How to install an exhaust fan in a bathroom
GOST 50571.11 divides bathrooms into zones, according to which an exhaust fan is installed in a bathroom.
The zero zone is the volume of the bath or shower tray itself. The area is not related to exhaust fans.
The first zone extends above the perimeter of the bathroom or shower tray from the floor to the horizontal plane, located 2.25 meters above the floor. Zero area is subtracted from the specified segment. Only heaters are allowed here. But! The ban applies to exhaust fans with a voltage of 220 V, powered by an industrial network. It is worth stopping the choice of a fan for a bathroom on a 12 V DC supply( or alternating current), the limitation disappears. It remains to choose the type of protection enclosure IP25.Explain where the requirements for the exhaust fan come from. The second figure follows directly from p. 701.512.2, the second - from the requirement of operating the BSNN systems( safe undervoltage to 50 V ac or 120 V dc, including = 12 V, p. 701.4184.108.40.206).
The second zone is located beyond the perimeter of the bathroom( shower tray) and ends at a distance of 60 cm from it. The angles are formed by the intersections of the planes of the sides, more distant than the middle part. The upper horizontal plane passes at a distance of 2.25 meters from the floor. Here it is allowed to place in addition to water heaters and lamps with electrical protection class II.However, the BSNN devices are not included in the specified categories. Feel free to put the fan under the ceiling, if it is powered from a source of 12 V and wears a case protection class of at least IP24( for public showers and toilets - IP25).
Zone three is the first area where it is allowed to use devices at 220 V. It extends from the borders of the second area by 2.4 meters and is bounded from above at a similar level. There are a lot of restrictions for the use of devices for 220 V in the specified location. This is the ability to install equipment with protection in three options: the use of a differential circuit breaker with a response threshold no higher than 30 mA, the use of an individual isolation transformer without grounding the selected secondary winding point, the use of BSSN systems, which we are talking about now.
Standards and Tips
They are interested in what is above the 2.25 meter plane. This is an area that can be used without restrictions. Within reasonable limits, of course. Standards remain that directly prohibit the installation of switchboards( and boxes) and other devices in such places. But with regard to exhaust standard restrictions are not imposed. We strongly recommend to buy equipment for 12 V. As for the switchboard, this is a converter with a DIN line, and we take the fan for a constant voltage, but of sufficient power.
Conductors of BSN systems are fenced off from others. When laying inside the bathroom, if possible, try to apply insulation according to GOST 30331.3 p. 413.2( reinforced insulation, electrical safety class II or similar).There is no requirement for wiring laid deeper than 5 cm in the wall. Along the whole length it is necessary to protect the conductors of the BSNN from others with the help of metal screens, hoses, pipes. The use of the above structures is prohibited on the territory of the bathroom. All that remains is an open( on the surface of the wall) or hidden( under the surface of the wall) gasket inside the plastic security elements.
Section is selected based on power requirements. A table 2.1.1 was developed in the EMP 6, where the minimum dimensions are normalized. For example, especially flexible conductors( consisting of a set of wires, class 3 and above) are allowed to be used for household electric consumers by soldering with a cross section of 0.35 square millimeters of copper. This is the minimum allowed by the standard. And although the current is minimal, the power is low, we do not recommend to go far to the side. There are two restrictions from below - fan consumption for the bathroom and recommendations for the OU 6.
How to calculate the exhaust fan consumption for a bathroom
The issues of the minimum copper cross-section and the class of flexibility affecting the price were raised. The more flexible the cable, the more expensive the thicker the wire, the more it will have to pay. Choose a fan for the toilet, so as not to overpay, it is recommended, focusing on performance. Conditions vary from person to person.
Some people, without hesitation, put on powerful exhaust fans, pumping their own smells to their neighbors. There are consumers who choose too weak a model, after installation the product does not cope with the responsibilities. Start choosing an exhaust fan with a simple one: try to understand if there is a back draft. For residents of the lower floors, this is irrelevant, with the increase in height the need for a powerful exhaust fan increases. Check the availability of reverse thrust will help a sheet of A4 paper. It is necessary to cover the ventilation hole with paper, if there is no sticking, the draft is unsatisfactory. The power of the device is chosen more.
Take an anemometer. On Aliexpress costs 800 rubles. The flow rate is determined, then, based on the cross-sectional area, the air flow is calculated. The speed of movement along the walls is lower than in the center. According to OS ABOK STANDARD-1, the exhaust fan air flow rate is:
- For a bath or toilet room - 25 cubic meters per hour.
- For a combined bathroom - 50 cubic meters per hour( if not used, the air exchange rate is 0.5 1 / h, it turns out - once every two hours).
- For the bathroom of the hotel room:
- The room is used - 120 cubic meters per hour.
- The room is not used - 20 cubic meters per hour.
- For a public toilet at least 75 cubic meters per hour per person.
. We strive to achieve these indicators. First, we examine the ventilation system with an anemometer to ensure the parameters. The flow velocity over the cross section is not uniform. The average velocity is in the form of an integral over the sectional area with a division by the area value. To simplify, average.
Divide( with the help of a ruler) cross-section into equivalent areas, we measure in each. We try to average for the segment( purely visually, according to the readings of the anemometer).Then the arithmetic average of all speeds is calculated. The result will be approximate, the quality depends on the ability to measure. In the course of the experiment, it is not necessary to block part of the section with your hand. It is ideal to hold the anemometer on a steel bar, the instrument case introduces an error.
Well, if you can get a remote anemometer. He has a measuring blade taken out on a steel pipe, cord or flexible corrugation. In each case, make sure that the device minimally overlaps the cross section of the ventilation passage. At home it is realizable. The situation is much simpler when the choice of a fan for the toilet has already been made. Here is a grid, to which we will losslessly insert an anemometer with a side, without blocking the section, we will measure it.
It is difficult to calculate the area if the protective grid is not a simple configuration. It is recommended instead of numerical methods to use natural. To do this, the paper is drawing any color of the protective grille of the fan. The free part is cut and folded. If necessary, each piece is divided into parts. The task is to get a rectangle, multiplying the sides of which, we get the desired area. It now remains to multiply it by the speed output by the anemometer, to get the result.
The figure found is compared with the standard. If the value is insufficient, a powerful exhaust fan is required. Depending on the data obtained, the question of the need for constant or temporary operation of the device is decided. Even - is it necessary to install an exhaust fan! After using the bathroom, it is necessary to increase the exchange rate. Adjust the speed of the exhaust fan.
How to choose the equipment for the ventilation of the bathroom
Above the recommendations are given in the general figures, which are considered just necessary. Now it is clear that a fan with a capacity of less than 50 cubic meters per hour is not suitable for a bathroom. To select the power consider:
- Fan speed is the same, determining the flow rate. If the channel is clogged or badly passes air, to maintain the speed you have to apply a large force.
- Power is the ability of the fan to maintain momentum. It is easier to illustrate with current tongs and a drill. At the start, its collector engine consumes almost the nominal value. Lasts a fraction of a second at idle. Then the power consumption is reduced. It is necessary to start drilling, to maintain speed you need to make great efforts. As a result, power consumption increases.
Similar occurs in our case. Take the device with the maximum power, all other things being equal( the same flow rate).This does not mean much consumption. But if necessary, the exhaust fan can push the air column vertically up through the pipe. It is clear, the cost of the product will be significant.
An asynchronous motor is acceptable inside the exhaust fan. During the test run in the store, you will hear the rustle of the blades. Powerful hoods are usually built on collector engines. In the bathroom equipment rumbles heavily at night. Think about the neighbors.
Regarding speed, a voltage regulator of 12 V( 0 to 12 V) will help to solve the situation. Do not rush to take in the store for a current of 50 A for 500 rubles, such models are designed for heaters and lighting. Think about how an exhaust fan with a capacity of 75 cubic meters per hour can spend 600 watts? In our case, the device will hardly reach a hundred. And this is already 10 A. Regulators on microchips are characterized by high efficiency, this is a definite plus.