By definition and common sense ventilation efficiency is the ability to create the required quality of the air environment in the serviced premises.

The efficiency of ventilation is determined by the methods of instrumental air control working area. If in normal operation the concentration of the main pollutant is within the normative limits, then ventilation is effective.

In today's practice, a slightly different understanding has been entrenched: the effectiveness of ventilation is called its compliance with the project or standards, ideally both.

In the general case, this is wrong, because ventilation systems that comply with the project and standards may be inefficient, i.e. not provide the required quality air environment.

But it is difficult to explain this to each potential customer for a long time at the first meeting, so when they ask for a check on the effectiveness of ventilation, I immediately think that instrumental control of ventilation systems for compliance with standards is needed and in nine cases out of ten it turns out. Usually they request an effectiveness check at the request of Rospotrebnadzor inspectors.

To be more precise, I try myself, and suggest to colleagues, to call this work "testing the effectiveness ventilation systems". So it is clear to customers, and technically it is possible to understand that we are talking about aerodynamic tests of ventilation systems, and not instrumental control of the air in the working area.

Periodic testing of ventilation efficiency is part of the system efficient operation buildings. Theoretically, the owner of the relevant objects or his tenants are interested in this.

In practice, small and medium-sized entrepreneurs engage in ventilation only if it is impossible or dangerous to work without it: in a busy painting and welding industry, etc.

On large industrial enterprises, in medical and educational institutions, ventilation is controlled by state inspections, so the owners are forced to periodically provide documents on the effectiveness of ventilation.

Such documents are properly executed passports of ventilation systems, summary tables of air exchange rates, aerodynamic test reports. In fact, ventilation is not always checked at the same time.

This work relates to the activities of production control.

Checking the efficiency of ventilation

The purpose of ventilation is to provide at least the normative air exchange, the norms are developed for the minimum air flow that is safe for health.

Thus, any deviation from the normative air exchange downwards is harmful to health. There is not enough air to efficiently dilute the emitted hazards and maintain an acceptable oxygen concentration. In rooms with people, an increase in the concentration of carbon dioxide is most characteristic. Signs of insufficient ventilation are:

• reduced performance;
• inability to concentrate;
• drowsiness;
• frequent respiratory diseases;
• deterioration of health by the end of the working day, which quickly passes after leaving the premises;
• when odors spread, they remain indoors for a long time.

In rooms with moisture, these are kitchens, showers, pools, etc. with insufficient ventilation, windows and, sometimes, walls fog up. This is especially bad, as it promotes the development of fungi.

To put the systems into operation after the installation is completed, commissioning is carried out on them, as a result of which the design indicators of air exchange are provided.

But the parameters ventilation units and networks do not remain constant, they change over time, usually in the direction of reducing air exchange and misalignment of the network.

why do you need

To make sure that the actual air exchanges provided by ventilation are in accordance with the design or regulations, periodic ventilation tests are carried out efficiency checks.

frequency of ventilation efficiency checks

Regulatory frequency is determined by sanitary standards, SanPiN, CH and guidelines MU. Usually annual checks are required for local ventilation, every three years for general ventilation and air curtains.

In large enterprises with serious attitude to health, the frequency is set by themselves, at least, of course, normative, but sometimes more often so modern air handling units complex and less reliable, need to be checked more frequently.

In addition, network installations are not always done well enough to guarantee long-term leak-free operation. When the installations are put into operation, they work, but then the network is depressurized. If this happens in a place inaccessible to inspections, then such a defect can only be determined by measurement.

who performs the ventilation efficiency test

If the regulatory documents indicate that the inspection is carried out by a licensed organization, then an SRO permit is required, the licenses have been canceled.

If the regulations say that accreditation is needed, then an accredited laboratory is needed accordingly.

If there is no explicit indication, then for most objects the work can be carried out by an individual entrepreneur.

how is it carried out

To start work, the customer must draw up a technical assignment for checking the effectiveness of ventilation systems. From the assignment, the scope of work, scope of work and additional wishes of the customer should be clear.

Having received the terms of reference, we first consider the estimate, if the price suits, then a work program and a detailed estimate are drawn up. We work with all new customers for ourselves with full or partial prepayment and stage-by-stage payment.

The main instrument of the efficiency test kit: differential pressure gauge, thermocouple, Pitot-Prandtl tube.

customers

The proportions of requests we receive by industry are shown in the diagram. In industry, this is primarily metallurgy and mechanical engineering, in medicine, medium and large hospitals, individual x-ray rooms.

Approximate proportions of requests on the diagram:

progress in performance testing

According to the methodology, all instrumental measurements are performed in accordance with the scope of work. Fans and networks are usually tested, this is enough to report to the inspections. Other measurements may be required for your own needs.

We do not make electrical measurements, this is prohibited by safety regulations. Such measurements are carried out by electrical laboratories or services of the enterprise itself.

Some companies are trying to extract maximum benefit of measurements, they are carried out in three seasons, in winter, summer and in the transitional season, which makes it possible, when comparing the results, to obtain some kind of measurements when adjusting for a sanitary effect.

results

Records about the actual parameters of the operation of ventilation units are made in the passports. Measurement protocols are attached to the passports. The table of air exchange rates for rooms is drawn up separately.

A technical report is not required, but can be provided if it is in the terms of reference. The report may contain: summary tables of ventilation parameters, balances, a list of defects, measures to elimination of defects, in a word, everything that a performer can do and from which they can get useful information customer specialists.

ventilation energy efficiency

There was a demand for the definition of energy efficiency and the development of measures to improve it. This makes sense, in some enterprises 20-30% of electricity is spent on driving fans, so you can save.

Technically, it is easy for a specialist to determine the actual efficiency of the ventilation system and compare it with the theoretical and practically achievable. But in order to increase efficiency, it is usually necessary to change engines and significantly change the network, which is rarely done.

Photo album

Checking the effectiveness of ventilation in a medical facility

At existing medical facilities, measurements are hampered by the presence of sedentary patients, the requirements for the sterility of some rooms, the clutter of the wards and ancillary facilities.

Checking the efficiency of ventilation in an industrial plant

In the background is a fan, on the right is a heat exchanger.

At industrial enterprises, sometimes there are specialists in the operation service!

Need a ventilation test?

Specialization is our advantage. For any kind of work related to performance testing and production control ventilation systems, we will do better and cheaper less specialized colleagues.

I registered the rights to this updated article in Yandex.

bad signs

Of course, I am interested in what they write about ventilation on the Internet I will say this, I use Wikipedia, but in my professional field I find its articles completely unsatisfactory. Sometimes even wrong. This is also alarming when reading on topics in which I am not an expert.

The picture is similar for specialized sites. Articles are written not by specialists, but by certain “copywriters” who sculpt their masterpieces based on the results of Internet searches. So I often see unquoted and sometimes mangled quotes from my articles.

But the fact is that being in the technical context of my specialty, I know the specialized literature, especially the normative one, and use the terms in their technical meaning.

Copywriters, with all due respect to the best of them, are not capable of this, since they do not have a specialized education. Even after rewriting my articles, they make a lot of mistakes.

Examples below:

ventilation shafts

there is no such term: there are channels in the construction design, which are sometimes called mines, and in fact, air ducts

act of failure

there is a list of defects

defective list

there is no such term there is a list of defects. Unfortunately, one of my colleagues persistently uses this incorrect phrase. So sunk into him in his youth. I, in turn, say "turbulence", as one of my authoritative mentors used to say a long time ago.

This is mistake. But as it happens now, this mistake - I'm talking about a "defective statement", spread among amateurs and even penetrated into the illiterate regulatory and technical documentation of the new "generation".

Without specialists, it is impossible to assess the effectiveness of ventilation.

Ventilation efficiency is largely a consumer characteristic, like the taste of a loaf. You don't have to be a baker to appreciate the taste of a loaf.

For example: in mansions, the standard for minimum air exchange is often violated. But in fact, if one person has 20-30 square meters area, then natural ventilation and air permeability of structures is sufficient, i.e. unorganized air exchange. Forced ventilation need not.

A specialist is needed if there is a problem.

After conducting aerodynamic tests, the specialist determines whether the ventilation complies with the project. If it corresponds, but the consumer is dissatisfied (with the taste, so to speak, of a loaf), then the specialist concludes that for this consumer minimum requirements to ventilation, reflected in the project, displayed in the standards, are insufficient.

Pneumatic holes

There are pneumometric tubes. And pit holes. I don't like this term, as there are tubes MIOT, SIOT, NIIOGAZ, VTI, etc. Pitot tube this is a special case, also called incorrectly the most common tube for aerodynamic measurements is the Pitot-Prandtl tube, but in foreign practice it has become fixed as a “Pitot tube” and ours often repeat this inaccuracy

During operation, engineering systems are subject to repair, transfer, replacement of components and equipment, and other various works. All of this can affect correct work system, including possible errors in calculation, design or installation, or a changed load on the system, or vice versa, an increase in efficiency in this case, an expert assessment of the system is required. Peer review includes a report on the operation of the system, including all the results of the evaluation and recommendations for improvement.

Study of ventilation systems

In order to form an opinion about the operation of the system, it is necessary to understand what condition it is in, what equipment and automation are installed, and many other parameters, this requires access to all parts of the system.

What is included in the study of the ventilation system:

• Visual inspection of the system and equipment for defects
• Checking the operating mode of the equipment
• Equipment Condition Assessment
• Checking the possibility of regulation of the system
• Interviewing customer employees about system problems in their premises
• Instrumental air flow check
• System Design Evaluation
• Checking the compliance of the system with the project and analyzing the impact of possible deviations
• Verification of design calculations
• Calculation of air flow rates and other system parameters at the time of inspection
• Evaluation of system performance and possible upgrades or repairs

A full range of expertise will allow you to very accurately determine the current state of the system, as well as give an understanding of what is better to change, in some cases you can get by with rebalancing and reconfiguring the automation system, in others it may require replacement ventilation equipment, thirdly, it is possible to replace sections of air ducts or air distribution devices. If the customer does not have an operational service, then, with a very high degree of probability, there is practically no understanding of what is happening with the ventilation system. Therefore, we offer service work not only for ventilation systems, but also maintenance of refrigeration equipment and others engineering systems buildings, the advantage of this approach is a complete and absolutely clear understanding of the state of the system.

Instrumental measurements of ventilation

It is necessary to dwell in more detail on the measurements of ventilation systems, people's feelings are individual, and therefore it is impossible to judge from them whether the system works correctly or not, which is why instrumental measurements can show the real picture. Measurements are carried out using a special device - anemometer, which shows the speed of the air flow, it is also necessary to check the air temperature, this will help to correctly configure the automation, and also show how well the isolated system is. Knowing the air speed and cross-sectional area, our specialists and ventilation systems can calculate the air flow. Having taken measurements on the inner gratings, it is desirable to take measurements on the outer grating, so you can find out how tight the system is.

Checking the effectiveness of the ventilation system

Another important point which needs to be discussed in more detail is the efficiency of the system. In fact, efficiency answers the question of whether the system copes with the load placed on it, whether it provides normalized air parameters in the room, which is very important in production. The answers to these questions lie in measurements and theoretical calculation, because it is the calculation in this matter that is of decisive importance, and the error in it affects the operation of the system. A weak ventilation system will not provide normalized air purity, and an oversized one will consume too many resources, this is how you can understand the effectiveness of the ventilation system. If the customer does not have a project of the necessary system, OVK-Group specialists can perform work on the restoration of the ventilation system project, heating, air conditioning and other engineering systems of buildings. At commercial facilities where tenants often change, this is a very urgent problem, projects are lost or reconstructed in such cases, an audit and examination of systems is very necessary.

By conducting research on the system and analyzing the results, one can understand how well or poorly the system is performing and where improvement is desirable. Although the equipment is the most important part of the equipment and is responsible for the correct operation of the system, but since almost all supply and exhaust units are recruited from sections, then, if necessary, these sections can be added or changed, improving the operation of the system. Recommendations for improvement draw attention to the problems identified during the review and show how to solve these problems.

21.07.2017 15:44

Why are ventilation measurements and analyzes performed:

1. Commissioning of new or facilities after reconstruction. Article 20 of the Federal Law of December 30, 2009 No. 384-FZ: “In the design documents of buildings, it is necessary to provide for equipping the premises with ventilation systems. Buildings can be equipped with air conditioning systems. Quantity harmful substances in the air supplied to the room through ventilation and air conditioning, should not exceed the limit allowable norms for similar structures or for the working area of ​​industrial buildings.
2. Examination of ventilation systems for compliance with the regulatory framework of Rospotrebnadzor and Rostekhnadzor, the relevant GOSTs, SanPiNam, RD and other regulatory documentation.
3. Study of ventilation in order to develop a program to improve working conditions.

Equipment for the analysis of ventilation efficiency:

1. Vane anemometers or hot-wire anemometers are available in any research organization.
2. The differential pressure gauge and PITO tube are unfamiliar to most, but easy to operate and efficient.
3. A contact thermometer is a forgotten device, but almost everyone has it.
4. Tachometer
5. Temperature, humidity and air pressure meter.

There are additional devices, but their complexity and price are not comparable with those already listed (Meteoscope, IR meter, thermohygrometer, air ion counter, barometer, manometer).

Ventilation

The main thing that a living organism needs is clean air. Target ventilation systems- providing an environment that meets sanitary and hygienic standards.

Air supply methods:

• Fresh air intake through an open window.
• Ventilation with natural and mechanized draft.
• Air heating systems, air conditioning systems.

Objects requiring ventilation

• Non-gassed and dust-free premises equipped with microclimate systems in which people are constantly present. These are almost all offices, shopping areas of our time.
• Industrial premises, in the air environment of which harmful substances are released.
• Buildings that are particularly demanding on air quality and microclimate (schools, preschool institutions, healthcare facilities).

Ventilation systems are used in almost all buildings and structures.

Ventilation is the final sanitary instrument of a set of measures to ensure a healthy atmosphere in isolated rooms. It helps fight excess moisture, heat, gas and dust.

There are direct and indirect ways to analyze the effect of ventilation systems

Indirect Methods include an assessment of the compliance of the air in the production building with the accepted standards for the content of harmful substances, temperature, humidity and movement of air masses, thermal radiation.

Direct Methods- air speed, its temperature, capacity, pressure, rotational speed of the ventilation unit blades, noise and vibration of the fan parts, the content of hazardous substances in the inflow of the air jet.

Examination of the efficiency of the ventilation system is carried out by determining the speed and temperature of the air in the working area, openings and sections of devices that receive air flow, in transport, installation openings, in the supply jets of devices that supply air. Calculation of the performance of ventilation units, measurement of pressure in the supply and exhaust systems, measurement of the pressure difference in industrial buildings in comparison with adjacent premises.

Based on the results of the studies performed, a report or passport of the ventilation system is compiled, which is final stage certification.

That's all the knowledge that is needed to analyze the effectiveness of ventilation: device, purpose, requirements, standards, work with equipment, documentation and accreditation.

The construction of a residential building at the design stage provides for the mandatory presence of channels for natural ventilation. From a safety point of view, this applies primarily to houses with installed gas appliances. Improper circulation or insufficient air supply can also lead to negative consequences.

Checking ventilation as a vital necessity

Ventilation of premises is understood as the entry of air into the apartment from the outside, ensuring its ventilation, displacement of gaseous waste products of humans, animals, etc. Ventilation systems include devices and equipment that ensure the regulation of air exchange. There are several types of ventilation systems, but in multi-storey residential buildings, there is mainly a supply and exhaust type of ventilation.

Its absence or ineffective work will immediately be noticed by apartment owners in high-rise building. Main features:

• deterioration in the well-being of people;
• penetration of odors from neighbors;
• the formation of mold, fungus in the bathroom and bathroom;
• high humidity in the rooms, linen that does not dry out for a long time;
• the spread of odors from the toilet, kitchen throughout the apartment.

If these symptoms are present, a ventilation check is performed. Its main goal is to eliminate the listed problems, prevent damage to household items and furniture. The main requirement is the creation of a healthy microclimate.

Analysis of ventilation efficiency: tasks to be solved

• Identification of compliance (non-compliance) of the microclimate with sanitary requirements.
• An analysis of the work separately for the inflow and exhaust gives an actual picture of the functioning of the home household appliances, devices ( gas boiler and plates).
• The shortcomings identified during the verification process may serve as a reason for cleaning the ventilation ducts, arranging air vents, installing additional equipment (supply valves, fans under forced exhaust, etc.)

Attention! Regulations regulating the operation of ventilation is SanPiN 2.1.2.1002-00 (PDN microclimate and indoor air), an addition to SNiP 2.08.01-89 Handbook "Heating and ventilation of residential buildings", SNiP 31-01-2003 by types of ventilation systems and other. According to them, the regularity of checking ventilation shafts, channels is carried out once a year (at least). If heating and cooking installations are operated all year round, ventilation should be inspected at least 2 times.

How can I organize an audit?

During the survey supply and exhaust systems the compliance of air exchange in rooms with different purposes with the requirements of the project and sanitary standards is revealed. In good condition, properly designed ventilation shafts are visually hidden, their work is not audible. There are several ways to check the ventilation in an apartment.

Match

The effect of a lit candle (match). A burning flame brought to ventilation grille in the bathroom or in the kitchen to a channel closed by a grate will show the operation of the ventilation. If the vertical column of flame, with the window (window) open, deviated into the room or remained in the same position, then the system is not working. But this method is dangerous and is not recommended by employees of the gas supply organization. In the event of a gas leak in the house open fire candles can provoke an explosion.

Paper

Safe, but no less effective "paper" option. With the window open, a sheet of newspaper or other thin paper placed against the grate should adhere tightly to it and be held by a pull.

These methods justify themselves only in the cold season. In the heat, at almost the same temperatures outside and inside the room, the laws of physics for the displacement of colder air warm lungs the masses don't work. Therefore, regular ventilation is organized. If malfunctions are found in the operation of ventilation, measures are taken to eliminate them.

Devices

A professional ventilation survey assesses the degree of clogging of floor and common house ventilation ducts. The power of the air draft and the degree of "sucking" that occurs due to the formation of reduced pressure are checked.

Using devices to evaluate the effectiveness of ventilation

The most accurate ventilation test in apartment building- instrumental measurements. An anemometer is used. Available for personal use the simplest model. Representatives of the sanitary service work with more advanced devices for calculating the rate of air exchange in rooms of different purposes. Such anemometers have remote sensors and built-in computing modules.

According to current regulations natural air movement should be:

• for the kitchen - 60 m3 / h (without a gas stove);
• for a bathroom and a bathroom - 25 m3 / h.

The anemometer reading is the speed of air movement in the ventilation duct. Knowing it, as well as the cross section of the lattice, it is possible, using special tables, to calculate the performance of the system.

Important! Measurements are carried out for each exhaust shaft and the causes of the identified failures in the operation of ventilation are clarified.

Measurement algorithm

• By opening the window, air flow is created.
• The ventilation channel is released from the grate.
• The impeller of the included anemometer is placed in the channel.
• The instrument readings are read.
• Actual measurements are compared with normative data.

Attention! In the exhaust ventilation shaft, the air velocity must be at least 5 m/s. In bends - at least 3 m / s.

What tasks does professional expertise solve?

Most often, the cause of misted glass, the formation of fungus, dampness and stale air in the room lies in the mistakes of designers and builders. Their correction is impossible without radical measures: overhaul or home renovation. An independent inspection reveals the flaws of builders during the installation of shafts, ducts, highways, and also proposes measures to eliminate them.

Checking the ventilation in the apartment management company should be carried out on the basis of the "Rules for the maintenance of common property in an apartment building". The document contains a list successive steps keeping it in good condition. This includes:

• system performance analysis and maintenance;
• Troubleshooting causing excessive levels of vibration and noise during operation;
• development of restoration and repair measures, etc.

Important! The company is responsible for the technical serviceability of the ventilation ducts, therefore it is obliged to check the operation of the systems every six months (in summer and winter). Regardless of the type of air exchange organization, the maintenance of residential buildings is confirmed by an inspection report.

If the building with inefficient ventilation is a multi-apartment new building, then it is covered by a guarantee (at least 5 years). It is necessary to require the developer to conduct an inspection of the ventilation system, troubleshooting.

When controversial situations an independent survey is being carried out in an apartment building. The examination allows to identify the reasons for the inefficiency of ventilation, non-compliance with construction and installation rules when installing ventilation shafts. Indicates a list of works to improve aeration. All proposals are documented. Recommendations are given to improve the efficiency of the system in different areas of the apartment and house.

Shows how quickly the exhaust air is removed from the room and is determined by the percentage of the concentration of harmful impurities in the exhaust air to the concentration of harmful impurities in the room .

Efficiency determines the quality of air exchange and shows how the ventilation system is able to provide comfortable conditions for air purity. This indicator of air exchange directly depends on the geometry of the room, relative position supply and exhaust ducts, density and distribution of sources of harmful impurities, etc.

Another parameter that determines the quality is the coefficient of air exchange.

The air exchange rate is a percentage of the air replacement rate in the room, which can be determined by the formula:

This parameter depends on the conditions of air distribution in the room, location and geometric parameters diffusers, location of heat sources, etc. To date, there are two types of air exchange in an enclosed space - ventilation by mixing and displacement.

8. Supply and exhaust ventilation system. Scope of ventilation systems with positive and negative air balance Scope of systems with recirculation;

Supply and exhaust general ventilation

It is used in rooms where it is necessary to provide increased and reliable air exchange. mechanical ventilation in industrial premises where a significant amount of harmful gases, vapors, dust is emitted, the exhaust must be 10% larger than the inflow so that harmful substances are not displaced into adjoining premises with less harm.

In the supply and exhaust ventilation system, it is possible to use not only outdoor air, but also indoor air after it has been cleaned. reuse indoor air is called recirculation and is carried out during the cold season to save heat spent on heating supply air. However, the possibility of recirculation is determined by a number of sanitary-hygienic and anti-burning requirements

supply system ventilation with mechanical stimulation can be performed with recycling. Recirculation is the mixing of exhaust air with supply air. Recycling can be complete or partial. Partial recirculation is used in conventional ventilation systems in working time because outside air is needed in the room. The minimum amount of outside air must not be less than sanitary standard. The use of recirculation allows you to save heat consumption in winter.

9. Systems of local ventilation. Purpose and scope;

local ventilation- this is an air exchange system in a limited part of space, the microclimate of which differs from its general atmosphere. That is, in fact, this type of ventilation is intended for installation at a separately considered workplace.

In rooms with a local emission of harmful substances, the use of local ventilation makes it possible to reduce the amount of supplied and exhausted air by several times.

Types of local ventilation

To create a ventilation system at the workplace, one of two types is formed - exhaust or supply local ventilation.

exhaust local ventilation It is used for localized foci of harmful substances, when it is possible to prevent their spread throughout the production area. It consists in capturing and removing harmful emissions emitted into the air of the room. With its help, the emission of dust, smoke, gases is organized.

Forced local ventilation is designed for intensive supply of fresh air directly to the workplace, its cooling if necessary, as well as blowing with cooled air streams if there is significant thermal radiation. Application of local ventilation

Local ventilation is in many cases justified, and often simply objectively necessary. It is used in almost all industrial sectors, including in mines, chemical, metallurgical industries.

Depending on the type of hazard source (machine, bath, etc.), various local suctions are used, exhaust hoods, exhaust panels, etc. Onboard suction, for example, is conveniently located around the perimeter of the baths.

Benefits of Local Ventilation

These include, first of all, the ecological necessity associated with the most effective protection of the health of a worker in hazardous production. With its help, they prevent the occurrence and development of pulmonary and cancerous diseases, allergies, irritation of the mucous membrane of the eyes, and headaches.

The second significant advantage should be called the economic efficiency of its application. It consists in saving energy costs (up to 60%), as well as in increasing the productivity of working personnel (according to statistics - up to 20%). In addition, local ventilation contributes to additional heating of the air. production premises, which creates another article of savings.