In industry and at home today, you just can not do without a fan. With its help it is possible to move gaseous media at low pressure indicators. An important role is played by the fan performance, on which the amount of work performed by it depends.
How to find out fan performance
Modern fan
By purchasing a ventilating device, everyone wants to know and check its performance. The performance of the described device is called the volume of air pumped over a certain unit of time. Therefore, everyone wants to buy a device with greater performance! It is measured in “CFM,” which means cubic feet per minute or m³ (cubic meters) per hour.
An equally important characteristic of this device is its power, which is measured in "kW" and "kW". In this case, the variable value is the speed of rotation, measured in the number of revolutions produced per minute of time.
Calculation of the fan, or rather its performance is also associated with:
- the diameter of the blades;
- noise level;
- full pressure.
Fan performance is indicated on the packaging of the device or prescribed in the instructions that accompany it. Normally, such a device updates the air in the room every 4 minutes. An important indicator is the amount of available space. The larger it is, the greater the load on the described device. By the way, you can calculate the volume of the room where you need to "refresh the air" using a simple school formula: multiplying the height by width and length!
The required shift rate recommended by SNiP is the range from 10 to 12 times per hour. Multiplying the available room volume by any value from this range, you can get the necessary performance in a separate room. Summarizing the obtained value with the calculation of the area for all rooms of the house, you can find out the desired performance for the entire living area.
In practice, the norms required by the calculations are rarely implemented, therefore, in real conditions, everything is somewhat different, as for a good air flow. So, for the minimum established rate of air exchange in the room, it is enough to open a window or rely on the draft created in the ventilation duct.
Kitchen exhaust fan
Baths and kitchens require fans with higher performance, or here they should work longer than in other rooms, since taking a shower and cooking leads to a change in the composition of the air, saturating it with water vapor and carbon monoxide. For such rooms, the operation of the apparatus in a “reinforced hood”, which must be installed on the device, is suitable.
An important role is played by the installation of an axial fan, which is a bladed blower machine that transfers mechanical energy in the form of kinetic and potential energy from the rotation of the blades located on the impeller. The calculation of the air exchange of axial fans is carried out taking into account the efficiency (efficiency), the aerodynamic characteristics of the device and the performance of the unit. This value can also be indicated in the instructions supplied with the device.
How to increase fan performance
The presence of fresh air in the premises is the key to good work and the well-being of all households.This can be done by installing fan equipment in the room that can cool the room evenly. At the same time, his quiet work is important, which does not create discomfort for others.
It is advisable to create an unhindered flow of air from the ceiling to the floor, which could be freely distributed around the entire perimeter of the room. Thanks to this, the device will heat up less and its performance will increase.
From the school course of physics it is known that cold air occupies the bottom of the room, and hot air up. Therefore, it is recommended to equip the air outflow at the bottom of the room. The presence of active air outflow and inflow requires the installation of blowers / blowers with equal performance.
Ventilation system
You can increase fan performance by switching it to efficient operation mode. Moreover, the operation of the device should be minimal when the household is not at home. In a different situation, it is recommended to increase the air supply in the room where people are located. If in the kitchen there is an active cooking process and the shower is working for a long time, it is recommended to increase the local air supply in these rooms to the maximum rate. Such “smart” ventilation is able to quickly and efficiently produce air exchange in any room.
For the described ventilation system, a special control unit is installed, which is connected to the processor. Sensors that can detect:
- degree of movement;
- amount of carbon dioxide;
- relative humidity.
Responsible for the selected mode of operation is the "control unit", which sets the mode of operation of the exhaust pumps. These devices can serve one or several rooms. The number of such devices depends on the area of the room. An extractor hood from the kitchen also joins here.
Cooker hood
The advantage of using the described “smart” ventilation system is the correct regulation of the performance of exhaust fans, allowing almost half to reduce the amount of air pumped in 24 hours. Also, less energy is consumed, which is a big plus for family budgets.
How to measure fan performance
Much depends on the performance of the ventilation system: both the condition of the house and its general well-being. So, the constant ventilation of the housing by opening the windows leads to the appearance of condensation on the windows and walls, and also stimulates the formation of mold in the corners. The lack of fresh air adversely affects the condition of the human lungs, manifested by the development of appropriate diseases and pathologies. Children growing up without ventilation can undermine their health for the rest of their lives.
You can use the following methods to measure the performance of a ventilation system:
Room Measurement
- Independent measurements. Roulette should measure the size of the room, determining its volume in meters. You can use a simple school formula to calculate the area of a room: the product of height, width and length. The result should be expressed in meters, which will be the total volume of the room.
- Obtaining information from reliable sources. BTI documents contain all the necessary information about the area of the premises. There is given the volume of all housing and heated area. You can also find the height from the ceiling to the floor and calculate the volume of a separate room.
Next, calculate the value characterizing the air exchange. In this case, the volume of a separate room should be multiplied by the desired number of air updates occurring within an hour. The number of air updates can be found in building codes (SNiP).
In this case, you should take the maximum number of updates in order to more accurately calculate the required power of the exhaust duct.
At home, the necessary ventilation device is also selected according to the obtained air exchange area. Standard ventilation ducts are characterized by low air exchange capacity. The situation can be helped by installing a recirculation exhaust system that can conduct air through the filters, sending it again to the room.
Scheme of installation of natural and forced ventilation
If the house does not have a ventilation duct, then the exhaust fan can be installed in a wall opening or on the ceiling. A joint of the ceiling and the wall is also suitable for these purposes. In this case, you can mount the device with a lower power value.
Exhaust ventilation in the kitchen
Thanks to exhaust kitchen ventilation, it is possible to conduct air exchange in the most problematic areas of the room. For example, improve the air quality in the kitchen at the time of cooking. Not only the general well-being of the people living here depends on the use of such structures, but also the condition of the walls in the living room. Recommended technical standards for the organization of ventilation:
- 60 m³ per hour (electric stove);
- 100 m³ per hour (gas hobs).
This value should be multiplied by the area of the room to find out the proper performance of the ventilation system. It is from the obtained value that the device should be selected with the appropriate electric motor. The installation of the hood above the hob allows for additional air exchange, preventing the spread of food aromas throughout the house. When connecting these elements, you should correctly select all components with equal sections.
With proper installation of the cooker hood, the ventilation shaft is connected with the attached device. Due to this, a complete removal of harmful chemical compounds formed from the component at the time of preparation is carried out.
