Calculators calculating the parameters of the ventilation system

Keeping your home’s interior atmosphere comfortable and healthy requires adequate ventilation. A well-designed ventilation system is essential for eliminating excess moisture, regulating the quality of the air inside buildings, and preventing the accumulation of dangerous pollutants. However, it can be difficult to choose the ideal parameters for such a system.

Ventilation system calculators can be useful in this situation. These useful tools provide precise calculations based on multiple factors, including your home’s size, number of occupants, and ventilation requirements, eliminating the guesswork out of designing a ventilation system. Both professionals and homeowners can find the ideal airflow rates, duct sizes, and fan capacities required to achieve effective and efficient ventilation by entering pertinent data.

Ventilation system calculators are now more advanced and offer users a variety of features and customization choices thanks to technological advancements. Everything from basic online calculators to intricate software programs is available, so there’s a tool for every need and ability level. These calculators are incredibly helpful whether you’re an HVAC professional trying to maximize system performance or a do-it-yourself enthusiast organizing a home renovation.

The ability of ventilation system calculators to take into account a variety of factors that affect indoor air quality and comfort is one of its main advantages. Ventilation requirements can be impacted by a number of factors, including the type of heating and cooling systems in use, the presence of combustion appliances, and the layout of the home. Calculators that take these variables into account can produce customized recommendations that guarantee ideal ventilation while lowering energy use and operational expenses.

Furthermore, homeowners can use ventilation system calculators to make well-informed decisions about replacing or modifying their current systems. These calculators offer insightful information about potential savings and benefits when it comes to upgrading to a more efficient heat recovery ventilation (HRV) or energy recovery ventilation (ERV) system, or adding supplemental ventilation to trouble spots like kitchens and bathrooms.

The subtleties of choosing an air duct

You can choose the air ducts’ parameters—that is, the round section’s diameter and the rectangular section’s dimensions—correctly by using the results of aerodynamic calculations.

Additionally, you can select a forced air supply device (fan) and calculate the pressure loss that occurs during the air movement process through the channel in parallel.

It is possible to calculate the necessary cross-section of air ducts by knowing the value of the air flow and the speed at which it moves.

In order to do this, the air flow is calculated using the reverse formula, S = l/3600*V.

You can compute the diameter using the result:

  • D is the diameter of the section of the duct;
  • S is the cross -sectional area of air channels (ducts), (m²);
  • π – the number "pi", a mathematical constant equal to 3.14;.

The number that comes out closest to the diameter of the product is chosen after it is compared to factory standards created by GOST.

If you must choose rectangular ducts over round ones, measure the length and width of the products rather than their diameter.

They use the approximate section as a guide when making their selections, along with the manufacturer’s size tables and the concept of A*b ≈ S. We would like to remind you that the width (b) to length (a) ratio should not be greater than one to three, per the norms.

Because of their ergonomic design, air ducts with square or rectangular sections can be installed back to the walls. This is accomplished by installing kitchen cabinets (mezzanines) or covering pipes over ceiling hinged structures with home hoods.

Rectangular channels are generally accepted to have minimum and maximum dimensions of 100 mm by 150 mm and 2000 mm, respectively. Round air ducts are advantageous because they have less resistance and little noise level indicators.

Convenient, safe, and lightweight plastic boxes designed specifically for use within apartments have recently been introduced.

What device the air speed is measured

While there are subtleties involved, all of these devices are small and easy to use.

Instruments for calculating air speed:

  • Winged anemometers
  • Temperature anemometers
  • Ultrasonic anemometers
  • Anemometers with a pipe pipe
  • Difmanometers
  • Balometers

One of the most straightforward devices to design is a winged anemometer. The impeller’s rotational speed determines the flow rate.

A temperature sensor is a feature of temperature anemometers. It is put in the air duct while it is hot, and the air flow rate is measured as it cools.

The primary wind speed is measured by ultrasound anemometers. They operate on the basis of measuring the variation in sound frequency at particular air flow control points.

An unique, small-diameter pipe is fitted to anemometers with pyo pipes. It is positioned in the center of the duct to measure the differential between static and total pressure. These are among the most widely used air measurement tools in the duct, but they have a disadvantage in that they are difficult to operate when there is a lot of dust present.

Difmanometers are capable of measuring air consumption in addition to speed. This device, which comes with a pyo tube, can measure air flows as high as 100 m/s.

When measuring air speed at the output of ventilation grilles and diffusers, balometers work best. They have a bell, which collects all of the air that exits the ventilation system, minimizing the measurement.

Selecting the appropriate ventilation system is essential for both efficiency and comfort when it comes to home insulation and heating. Similar to digital wizards, ventilation calculators assist you in determining the ideal airflow balance to maintain a cozy and fresh home. These tools create a customized ventilation plan based on variables such as the size of the room, the number of occupants, and the local climate. Homeowners can make sure they’re not only breathing clean air but also maximizing energy efficiency and lowering costs by using these calculators. Having proper ventilation ensures a healthier, happier house all year long, whether it’s for blocking out the winter cold or allowing summer breezes to enter.

Forms of the section

The pipes in this system are split into two categories based on the shape of the cross section: round and rectangular. Rounds are mostly utilized in large industrial companies. because they take up a lot of space in the room. For residential buildings, kindergartens, schools, and clinics, rectangular sections work well. Because they originate from them at least, noise vibrations, the pipe with the round section is the most noisy. From pipes that have a slightly larger cross-sectional area and a rectangular noise source.

Steel is the most common material used for pipes in both sections. In contrast, the stronger the steel used in pipes with a rectangular cross-section, the less solid and elastic the steel is used in round cross-section pipes.

To sum up, let me emphasize once more how important it is to pay attention to the ongoing calculations and air duct installation. Recall that if you do everything correctly, the system will function as intended overall. Naturally, security is another important consideration. Careful selection of system components is necessary. It’s important to keep in mind that cheap does not equate to high quality.

1 Proper air exchange

Every residential and commercial building should have a ventilation system in compliance with building and sanitary codes. Maintaining air balance and establishing a microclimate that is conducive to human work and relaxation are its primary duties. That is, there shouldn’t be an excessive amount of heat, moisture, or pollution in the atmosphere. Otherwise, a fungus and mold will grow on the surface of the furniture, walls, and ceiling, and the fast spread of pathogenic bacteria will start in an overly warm and raw atmosphere.

All of this will cause the individuals in the room to have respiratory issues and weaken their bodies’ defense mechanisms. You must heed the following advice in order to stop this from happening:

  • The composition of the air must meet hygienic norms.
  • In places with the wrong air exchange, equipment should be installed, increasing and regulating the speed of air flows.
  • Available ventilation systems must correspond to the functional features of the room.

The more bends in the air duct, the more noise and pressure the flows produce as they pass through the channels. Sanitary standards state that the purpose of the room and the time of day affect the noise level:

  • in hospital and sanatorium wards – 35-50 DBA;
  • in training rooms and classes – 40-55 DBA;
  • in residential apartments and rooms – 40-55 DBA;
  • in territories near hospitals and sanatoriums – 35–60 DBA;
  • in the territories adjacent to residential buildings – 45–70 DBA;
  • near schools – 55–70 DBA.

The highest values in the table pertain to the time span of 23 to 7 hours.

Calculation rules

The speed of the air masses in the ventilation channel is closely related to both noise and vibration. After all, if there are more turns and bends than are ideal, the flow through the pipes has the potential to produce alternating pressure that can surpass standard limits. Оогда сопротивление в каналах большое, обень меньше пкономичность вентиляторов и скорость воздуха.

Numerous elements influence the vibration threshold, such as the type of pipe used.

Standard noise levels

The SNIP denotes specific requirements that apply to residential, public, and production-type properties. The tables list all of the standards. In the event that the adopted norms are raised, the ventilation system’s design is flawed. Furthermore, it is acceptable to exceed the standard sound pressure for a brief period of time.

The channel system is created with any flaws that need to be fixed right away if the maximum allowable values are exceeded. Additionally capable of surpassing the vibration levels is the fan power. The duct’s maximum air speed shouldn’t be a factor in the noise’s increase.

Principles of evaluation

Ventilation pipes are made from a variety of materials, the most popular being metal and plastic pipes. Air ducts come in a variety of shapes, from ellipsoid to round and rectangular. Since the kind and function of the premises can differ greatly, SNiP can only show the exhaust pipe dimensions and cannot be used to normalize the volume of air masses. The registered norms are meant for use in social facilities, such as hospitals, schools, and preschools.

A set of formulas allows for the calculation of all dimensions. While there are no set guidelines for determining the air speed in the air ducts, SNiPs provide recommended standards for the necessary computation. Tables are used to represent all of the data.

You can add to the provided information as follows: if the hood is natural, the air speed should be less than 0.2 m/s and not exceed 2 m/s to prevent poor airflow in the space. For the main air ducts, the maximum permitted speed if forced ventilation is used is 8–11 m/s. If this criterion is raised, the ventilation system’s pressure will increase significantly, causing intolerable vibration and noise.

3 features of speed determination

The ventilation system’s noise and vibration levels are directly correlated with the air speed. For this reason, these indicators are also considered in the calculations. This is because vibration and noise are produced when air masses move. The quantity of pipe bends determines the intensity. There is also resistance, and the more resistance there is, the slower the speed. As a result, when forced ventilation is employed, fan performance rises.

Among the factors that should draw attention are:

  • Sanitary noise levels are indicated in the corresponding section of SNiP. Indicators for residential premises, industrial and public buildings are slightly different. For example, for a medical institution, the mark should not exceed 60 dB, and 70 dB is allowed for a workshop or other industrial premises. The average indicator for educational and medical institutions is 40 dB. It is worth noting that the norms for the night time of the day are slightly lower, and for the adjacent territories above.
  • An indicator of sound pressure is also considered important, which should not exceed 40 dB for residential and 50 dB for industrial premises.
  • The level of vibration directly affects the operation of the fans provided that the forced system is used. The maximum indicator depends on several factors: the size and material of pipes, installation quality, air flow rate, which passes through the channels.
  • The frequency of air exchange directly affects the process of cleansing the room from stagnant air and dust. Its quality depends on the type of ventilation system. When using a natural variety, it can be supplemented with aeration, that is, opening the windows and doors in order to strengthen air exchange. Artificial species involve the installation of forced or mechanical ventilation, as well as air conditioners. The multiplicity is determined by the amount of changes in the air masses and is calculated by the formula: n = v/w. The first letter means the amount of shifts in 1 hour, the second is the volume of clean air filling the room for an hour, the third is the area of the room itself.

The main formulas of aerodynamic calculation

First things first, the highway needs to have its aerodynamics calculated. Keep in mind that the system’s longest and most heavily used segment is the main air duct. The fan is chosen based on the outcomes of these computations.

However, remember to connect the remaining system branches as well.

It’s crucial! The diaphragm must be used if a link can’t be established within 10% of the air duct branches. The following formula is used to determine the diaphragm’s resistance coefficient:

Rectangular diaphragms must be installed at the junction site where the horizontal duct enters the vertical brick channel if the inconsistent is greater than 10%.

The primary calculation task is to determine pressure losses. Selecting the ideal air duct size and managing air speed simultaneously. Pressure losses in local resistances and pressure losses along the duct’s length (due to friction) add up to general pressure losses. Formulas are used to calculate them.

For steel ducts, these formulas are accurate; for all other cases, a factor is added. Depending on the air ducts’ speed and roughness, it is taken from the table.

It is acceptable to use the equivalent diameter for rectangular air pipelines.

Examine the procedure for calculating the aerodynamics of air ducts using formulas on the example of offices provided in the previous article. then display how it appears in the Excel application.

An example of calculation

The office computations indicate that the air exchange is 800 m3/hour. The assignment was to design office air ducts that were no higher than 200 mm. The customer provides the dimensions of the space. Air is delivered with a density of 1.2 kg/m3 and a temperature of 20 °C.

Entering the results into a table of this kind will make things easier.

Initially, we will compute the aerodynamics of the system’s main highway. Everything is now in order:

We divide the freeway into sections near the supply grilles. Each of the eight sieves in the room has a flow rate of 100 m3/h. Eleven sites were found. Fill in the table with the air flow for each section.

  • Record the length of each site.
  • The recommended maximum speed inside the duct for office premises is up to 5 m/s. Therefore, we select such a duct size so that the speed increases as it approaches ventilation equipment and does not exceed the maximum. This is done to avoid noise in ventilation. Take for the first section we take the duct 150×150, and for the last 800×250. V1 = l/3600f = 100/(3600*0.023) = 1.23 m/s. V11 = 3400/3600*0.2 = 4.72 m/with us the result suits us. Determine the dimensions of the air ducts and the speed according to this formula in each section and enter into the table.
  • We begin calculations of pressure losses. We determine the equivalent diameter for each section, for example, the first DE = 2*150*150/(150+150) = 150. Then we fill out all the data necessary for calculation from reference literature or calculate: re = 1.23*0.150/(15.11*10^-6) = 12210. λ = 0.11 (68/12210+0.1/0.15)^0.25 = 0.0996 The roughness of different materials is different.

  • Dynamic pressure PD = 1.2*1.23*1.23/2 = 0.9 PA is also recorded in the column.
  • From table 2.22 Determine the specific pressure losses or calculate R = pd*λ/d = 0.9*0.0996/0.15 = 0.6 p/m and enter into a column. Then, on each section, we determine the loss of pressure on friction: Δrtr = r*l*n = 0.6*2*1 = 1.2 p.
  • We take local resistance coefficients from reference literature. In the first section we have a grille and an increase in the duct in the amount of their CMS is 1.5.
  • Loss of pressure in local resistances δcrm = 1.5*0.9 = 1.35 PA
  • Find the bag of pressure losses in each site = 1.35+1.2 = 2.6 PA. And in the end, and pressure losses throughout the highway = 185.6 PA. The table by that time will have the form

Additionally, the same method is used to calculate the remaining branches and how they are linked. But let’s discuss this in more detail later.

Do I need to focus on SNiP

We followed the SNiP and MGSN recommendations in all of our computations. With the help of this regulatory documentation, you can ascertain the minimal ventilation performance required to guarantee that guests are comfortable in the space. To put it another way, the main goal of SNiP’s requirements is to reduce the cost of the ventilation system and its exploitation costs, which is important to consider when designing vendes for public and administrative buildings.

The situation is different in apartments and cottages because you are designing the ventilation for yourself, not for the typical resident, and there is no legal requirement to follow SNiP guidelines. Because of this, the system’s performance may be lower (to lower the system’s cost and energy consumption) or higher than the estimated value (to increase comfort). Furthermore, each person’s subjective level of comfort varies; for example, some people only need 30 to 40 m³/h, while others require 60 m³/h.

However, it is preferable to follow SNiP’s recommendations if you are unsure of the type of air exchange you require for a comfortable and healthy lifestyle. Modern supply units let you control productivity from a control panel, so you can already find a balance between comfort and cost when the ventilation system is operating.

Calculated air exchange

The maximum value for heat access, moisture access, receiving hazardous vapors and gases, sanitary standards, compensation for local extracts, and the standard frequency of air exchange are all taken into account when estimating the value of air exchange.

The multiplicity of air exchange or hygienic standards are typically used to calculate the air exchange of residential and public spaces.

Following the computation of the necessary air exchange, the air balance of the building is assembled, the number of air distributors is chosen, and the system’s aerodynamics is calculated. Therefore, if you want to ensure that your stay in the room is comfortable, we advise you not to overlook the air exchange calculation.

2 types of ventilation

The ventilation of the rooms when fresh air flows fall through open transums, windows, and doors and are expelled through exhaust grilles placed in the kitchen and bathroom is an example of a non-channel air exchange. Canal circulation can be either gravitational or tier and is achieved by putting in special ducts in the walls.

Natural air exchange is the easiest to organize on its own, has the simplest principle, and doesn’t require significant financial outlays. Nevertheless, because it is not always very strong, dangerous substances are eliminated prematurely. When forced ventilation is not sufficient to fulfill the role of air purification, natural ventilation is called upon.

It is implemented using a variety of equipment. You can achieve good air exchange throughout the entire apartment with the aid of a large installation that requires numerous pipes mounted in the attic or utility room, but this will require a significant financial and labor investment.

A regular change in air masses is provided by both forced and natural circulation. Multiplicity, the quantity of these shifts, is a crucial metric that describes the velocity of air flow in ventilation ducts. The frequency is computed using the formula n = v/w, which gives the measurement in cubic meters per hour.

  • W is the volume of the room.
  • V is the volume of clean air filling this room in 1 hour.

Why measure air speed

The condition of the supplied air is one of the most crucial elements for ventilation and air conditioning systems. That is, its attributes.

The following are the primary air flow parameters:

  • air temperature;
  • air humidity;
  • consumption of the amount of air;
  • flow rate;
  • pressure in the duct;
  • other factors (pollution, dusting …).

Normalized indicators are described for each of the parameters by SNiPs and GOSTs. Within the parameters of acceptable norms, the value of these indicators may vary depending on the project.

Although regulatory documents do not strictly regulate air duct speed, designers’ reference books do provide the recommended value for this parameter. You can read this article to learn how to calculate the air duct speed and become familiar with its acceptable values.

For instance, the recommended air movement speed through the main ventilation channels for civilian buildings is between 5 and 6 m/s. An accurate aerodynamic computation will provide the necessary speed to solve the air supply problem.

However, periodic control of air movement speed is required to maintain continuous observation of this speed mode. Why? Over time, ventilation and air ducts become contaminated, equipment may malfunction, and air duct joints may become depressurized. When servicing ventilation, measurements must also be completed along with scheduled inspections, cleanings, and repairs in general. They also measure other things, like the speed of flue gases.

Several useful tips and comments

As you can see from the formula (or by using calculators to perform real-world calculations), the air speed rises as the pipe diameter decreases. This fact can be used to their advantage:

  • There will be no losses or the need to lay an additional ventilation pipeline to ensure the necessary air flow, if the dimensions of the room do not allow the channels of large sizes;
  • You can lay pipelines of smaller sizes, which in most cases is simpler and more convenient;
  • The smaller the diameter of the channel, the cheaper its cost, the price will decrease by additional elements (damper, valves);
  • The smaller size of the pipes expands the possibilities of installation, they can be arranged as it should, practically without adjusting to external shy factors.

When installing a smaller diameter air duct, it’s important to keep in mind that as air speed increases, so does the dynamic pressure on the pipe walls, increasing the system’s resistance and necessitating the need for a more powerful fan and additional expenses. As a result, thorough calculation must be done prior to installation in order to prevent savings from becoming large expenses or even losses. Additionally, construction that does not adhere to NNUP standards may not be permitted to proceed.

Description of the ventilation system

A part of the ventilation system that comes in different sections and is composed of different materials is the air duct. In order to perform the best calculations, you will need to consider two extra parameters, such as the air exchange volume and speed in the air duct cross section, in addition to all of the individual element dimensions.

Immune system resistance can be considerably lowered and a number of respiratory diseases can be brought on by ventilation system violations. Furthermore, too much moisture can promote the growth of harmful bacteria and the emergence of fungi. Consequently, the following guidelines are followed when installing ventilation in homes and other buildings:

A ventilation system must be installed in every room. It’s crucial to follow the rules regarding air hygiene. Different ventilation system equipment circuits are needed in locations with different functional goals.

Think about the ideal hood and ventilation setup as demonstrated in this video:

The air duct calculation is an interesting one.

The importance of the correct air exchange

The primary objective of ventilation is to establish and preserve a comfortable and conducive atmosphere within residential and commercial spaces.

Particularly during the winter, if the building’s air exchange with the outside atmosphere is excessively strong, the interior air will not have enough time to warm up. The rooms will be too dry and cold as a result.

On the other hand, a low air renewal speed results in an unhealthy, overly warm, and damp atmosphere. In more advanced cases, it’s common to see mold and fungus growing on the walls.

A specific equilibrium of air circulation is required to sustain humidity markers and air temperature, both of which have a favorable impact on human well-being. This is the most crucial task that needs to be completed.

The ventilation ducts’ sectional length, number of bends in the track, and distance between sites with smaller air-conductive pipe diameters all affect how quickly air moves through them and how much air exchanges.

The ventilation system’s design and parameter calculations take all of these subtleties into consideration.

By using these computations, you can design dependable intra-domed ventilation that complies with all regulatory requirements that are stipulated in the "construction norms and rules."

Calculator Name Description
Heat Recovery Ventilation (HRV) Calculator Estimates energy savings and ventilation requirements by recovering heat from outgoing air.
Airflow Rate Calculator Determines the required airflow for optimal ventilation based on room size and occupancy.

Calculators for figuring out your ventilation system’s parameters can be very helpful in making sure your house is properly insulated and heated. These calculators allow you to enter specifics about your home and ideal ventilation setup, and they can calculate airflow, duct size, and other important parameters with precision. With this knowledge, homeowners are better equipped to decide what kind of insulation and heating system they need.

The ability of these calculators to customize recommendations to the particular features of your home is one of the main advantages of using them. Numerous variables, including the number of occupants, the size of the living area, and even the local climate, can affect how best to design a ventilation system. The calculators can provide customized solutions that optimize comfort and energy efficiency by taking these factors into account.

These calculators can also assist homeowners in projecting the expenses related to the installation and upkeep of a ventilation system. Before committing, people can evaluate the costs of various options by receiving estimates of energy consumption and possible savings. Better budgeting is made possible by this transparency, which also guarantees that homeowners can make decisions that support their financial objectives.

Furthermore, the significance of careful planning and design for home insulation and heating is highlighted by the use of calculators for ventilation system parameters. Those who are proactive about these aspects of house maintenance can steer clear of common problems like uneven heating, bad air quality, and excessive energy use. In the end, taking the time and making the effort to choose the ideal ventilation system can result in long-term cost savings as well as increased family comfort.

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