How to make a hood in a private house: technical standards + installation technology
Plastic windows, armored doors, on the one hand, retain the desired temperature in the premises, and on the other - cause problems with air exchange. Competently arranged extractor in a private house will relieve from the feeling of stuffiness and condensation.
In most cases, this is the only way to create a healthy microclimate in it.
Options for exhaust in a private house
Both in public buildings and in private houses, different types of ventilation systems are used. They differ in purpose, method of activating the air flow and the movement of air masses. The ventilation system designed to supply clean air to the house is called the supply air.
The design, the function of which is to remove the exhaust air outside the room, has the name exhaust. A special mission is ventilation with recirculation.In this case, mixing of the part of the air removed from the room with the external cold air masses takes place, with further heating of this mixture to the set temperature and returning it to the room.
The movement of air occurs as a result of processes proceeding naturally due to the displacement by cold air, which has a greater volumetric weight, of heated air with a weight lighter from the room.
The flow in such a system moves at a low speed, since the weight of the warm and cold mass differs by a small amount. It is irrational to use the air duct with a natural impulse if its horizontal length exceeds 8 m.
More effective is a system with artificial activation of the air flow, provided by the operation of the fans. The air ducts in this case are long and can pass through several rooms. Elements of the system are often placed in the attic. This option is justified for large buildings.
There is a division into channel and channelless systems. In the first case, the air moves through the channels and ducts, in the second, there is no organized movement of air. In this case, you have to open the window transom, doors. Natural ventilation creates a more comfortable environment for residents.
Required preliminary calculations
The initial parameter in the calculation is the volume of air that is drawn out and supplied to the room. There is not one technique, but in the most used, sanitary standards and room space are taken as a basis.
According to the requirement of the first, you need to build on the fact that the need for air in m3/ h for one person who spends most of the time in the house, depends on the purpose of the room:
- living room - 40;
- bedroom - 20;
- kitchen - 60;
- bathroom - 25.
Based on the second criterion, the following regulatory requirement is based on the following: 3 m of living space per 1 m²3replaceable air. When calculating the duct cross-section, they are guided by the fact that the optimal value of the air velocity in the central channel is 5 m / s, and in the side channel - a maximum of 3 m / s.
Independently determine the diameter of the pipe by the formula: S = L / 3600 / v. L - productivity, measured in m3/ h, v - air velocity in m / s. Data on the expenditure of air, depending on the section of the duct are summarized in the table.
Air ducts are made of metal, plastic, aluminum foil, polyester. The latter two are flexible systems. Their noise and heat insulation characteristics are good and they are perfect for a private house.
Natural air exchange in the house
The basis of natural air exchange is the property of gaseous and part of liquid substances with a higher temperature to rise up.Thus, the exhaust air is naturally discharged from the room through a vertically positioned exhaust duct, tightening, along the way, the outside air through the inlet ducts.
The inefficiency of the inlet ventilation is indicated by an excess of moisture in the room during cold weather or increased dryness in the warm. The presence of large amounts of dust, lack of oxygen - these are also signs of insufficient air flow from the outside.
The consequence of poor exhaust is the formation of fungus under the wallpaper, in the bathroom, the settling of soot on the kitchen walls, misted windows.
Check the operation of the hood is easy. It is enough to bring a sheet of paper to the vent grid. If a good one is used, it will arch towards the ventilation duct, otherwise nothing will happen. It should be concluded that the hood is clogged with something and to ensure thrust the channel must be cleaned.
To provide a private house with good ventilation you need to start with the calculation of air exchange. Based on its results, a cross section of the channels, a type of ventilation system are selected and a draft version of the ventilation scheme is made, where they indicate the places of passage of the air ducts and the installation of ventilation equipment, the intake points and the air mass outlet.
Private houses are mainly located outside the city, where the air, unlike the city, is cleaner and there is no need for additional cleaning. Therefore, natural ventilation for a private house is preferable.
A big obstacle to the entry of fresh air are plastic windows, in which there are no gaps, and the glass is very tight to the frames.
Outlet in the installation of the inlet valve. It is placed on the upper frame, so the air coming from the street goes under the ceiling and only after mixing with conventional flows and acquiring room temperature, it goes down.
The location of the exhaust system elements should ensure the passage of air flow with coverage of the whole house in the direction from the "clean" rooms to those where the air is most susceptible to pollution.
According to this rule, in rooms with special conditions, which include boilers, kitchens with a gas stove, basements, rooms with fireplaces and columns, toilets, the presence of exhaust is mandatory. In these rooms need valves.
There are infiltration valves installed on the wall. This pipe with a circular cross section is inserted into a through-hole in the wall and covered with gratings both on the inside and the outside.
The grid located inside can be adjusted - open and close completely or partially. When installing prefer a place near the window. Sometimes the intake valve is mounted behind the radiator and then the incoming air is immediately heated.
Requirements for ventilation of a private house
Sanitary standards put forward a number of requirements for the Armed Forces. When deciding how to make an effective hood in a private house, all points must be considered:
- The inner walls of the canals should be smooth.To ensure this condition, round or rectangular ducts of constant cross section are inserted into them.
- The vent stand at the bottom is equipped with a viewing door.It should close tightly.
- Exhaust channel lead to the roof with an elevation above it 1.5 m minimum.If the roof has a broken shape, then in order to avoid the occurrence of reverse thrust caused by the turbulence of the flows, a deflector is installed in the exhaust duct.
- The device of the ventilation shaft.If initially the ventilation system in the building was not provided, a side shaft is attached to one of the walls. To improve its traction it is necessary to warm.
- Compliance with the rules of the organization of ventilation.You can not combine the mechanical exhaust kitchen with a common sun. A separate channel is arranged for it, otherwise there will be problems with the functioning of natural traction in other areas of the house.
- The maximum allowable distance from the ceiling to the top of the ventilation grilles is 150 mm.Increasing this distance will cause stagnant air zones.
Doors that divide adjacent rooms, even when closed, should not prevent air from flowing.
The best solution is to purchase a door with a special decorative grille below. If a solid door is installed, a gap of no less than 2 cm is left between the floor and the door leaf or a row of holes is drilled at the bottom.
The essence of the basic requirement is that the volume of air to be removed must be equal to the amount of incoming air. If this rule is not observed, then various unpleasant odors will enter the room with the air. With a large imbalance between the volume of incoming air and exhaust drafts will appear.
Union of ventilation with recycling
Recirculation is called CB, when air removed from a room is returned back through the inflow with admixture of fresh air. The disadvantage is that its use is limited to SNiP, and in regions with cold climates it does not work very effectively. Its action is limited to one room.
The scheme of the recirculation system can be turned into an ordinary supply and exhaust ventilation by closing the recirculation valve and the complete opening of the supply and exhaust. If you do the opposite, the system starts to drive the air around.
When the intake and exhaust valves are opened only partially, mixing of fresh outside air will begin. By adjusting the degree of opening, optimize the flow of elements that provide a comfortable livelihoods.
Installation of forced exhaust of a private house
Forced air exchange in comparison with natural wins in many ways:
- It works regardless of the weather.
- Cleans the air more effectively.
- It is possible to adjust the rotation speed and fan power.
- The air flow can be set in motion not only with the help of a duct fan, but also through the use of candy bars, which are easy to install.
The main disadvantages are the dependence on power supply and the need for periodic replacement of individual elements. For forced ventilation there are several mechanisms.
It can be a single supply and exhaust unit, a dial-in unit system, an exhaust, channel conditioner. It is considered the most effective supply and exhaust CB. The design includes a fan, automation, sensors, filters.
Forced exhaust in the standard version has a single fan and is designed for small rooms. In the CB type-type equipment is the same, but it is placed separately. System power is in the range of 80-7,000 m3/ h
From the practical recommendations of experienced craftsmen, it follows that in a small house consisting of 2 rooms, an extractor hood, processing from 200 to 300 m, effectively works.3air per hour
In large buildings, it is necessary to install exhaust hoods with a capacity of 350 to 500 m3/ h
Technology installation hood in the kitchen
Hood in the kitchen is placed, as a rule, above the stove. It is necessary that the exhaust umbrella protrudes 100-150 mm beyond the plate.
Performance is chosen with a focus on the parameters of the room using the formula:
P = S x H x 12
Where the first symbol indicates the power of the second - the third area - the height of the kitchen.
Air ducts usually run along an indirect path, which may cause the draw power to decrease. For the guarantee, to the value obtained as a result of the calculation, add 30%. The installation technology is simple therefore, having understood the scheme, you can do all the work yourself.
When there is no built-in aircraft. then first make a hole in the wall that coincides in diameter with the cross section of the exhaust pipe. If we ignore this recommendation, the work will be accompanied by increased noise, and the air will flow out at a lower speed.
The design itself is placed at the station not less than 0.7 m from the surface of the electric stove and 0.8 m from the gas one.
The next step is to mark the attachment.Sometimes a drawing kit comes with the hood, but if it doesn’t turn out to be available, you can use the level and the tape measure. Next, fix the exhaust umbrella, observing horizontal position.
Connect the design to the previously completed outlet, connect to the mains and test. If the house has a gas water heater, then the ventilation pipe can be brought into the chimney of a boiler or a heating furnace.
The installation process of a kitchen hood with a masking dome will be demonstrated by the following photo selection:
Forced exhaust bathroom of a private house
In the bathroom for forced ventilation perform the installation of exhaust fans operating in a wet environment:
- power is supplied to the room and a socket is installed;
- a hole is made in the wall corresponding to the cross section of the fan coupling;
- the coupling is placed in the hole;
- drill through the mounting holes;
- connect the cable;
- removing the front panel from the fan, attach the latter to the wall;
- return the removed panel to its place;
- outside fix grill.
Such a system is advisable to use in the bathroom, located on the second floor. Usually, the CB of this room with the obligatory presence of the ventilation shaft is laid in the project. Air flow through the gap between the floor and the door, as well as through the vents.
Sometimes, as an option to solve the problem, how to make an outlet in the combined bathroom of a private house, along the wall of a building, something like a drainpipe with a recommended diameter of 110 mm protruding above the roof level is carried out.
The ventilation device of the hygienic premises uses axial fans, the installation of which is carried out in the standard sequence:
Basement ventilation device
For a basement, simple and efficient ventilation is needed, otherwise it will not respond to the requests made to it. For installation, 2 pipes with a cross-section from 80 to 150 mm, heat insulation, protective visors, grilles are needed.
The supply pipe is mounted at one end into the wall, departing from the floor about 0.3 m. The top of the pipe with a length of approximately 5.5 m must pass along the outer wall. The traction provides temperature differences in the upper and lower parts of the pipe.
The top of the pipes is protected by visors, which, in addition to the protective function, play not the last role in regulating the air flow rate.
The intensity of thrust depends on the difference between the lengths of the supply and exhaust pipes. The greater the difference, the more powerful the flow. Normal ventilation should ensure a 2-fold replacement of air within 60 minutes.
Conclusions and useful video on the topic
How to implement a ventilation project according to all the rules is described in this video:
You will familiarize yourself with the work of natural ventilation by watching this video:
Numerous factors affect the ventilation efficiency of your own home. When choosing the type of aircraft and performing calculations, you need to consider everything. Only when this condition is fulfilled will it function flawlessly.