Factory ventilation is now mandatory for today’s factory. There are many different ventilation measures used in the factory system. Depending on the investment costs of the business owner, appropriate ventilation measures will be taken. The following article , P69 Company will share with you how to calculate the air flow in the factory using the standard formula.

Why ventilate the factory?

Installing a factory ventilation system helps:

• Eliminate harmful gases and unnecessary gases inside the workshop to the outside environment. Normally, CO2 is the gas that needs to be eliminated most in human living spaces.
• Ensure that the air quality in the workplace is always clean and well-ventilated.
• Remove excess moisture and heat to the outside.
• Produce the required amount of oxygen for people working in the workshop.
• In some more special cases, ventilation systems are installed to overcome unexpected problems in the production process such as leakage of hazardous substances.

Currently, businesses are using two ventilation systems for factories, namely the ventilation system in the air-conditioned environment and the ventilation system to create cool ventilation.

The formula for calculating the design of factory ventilation flow

One of the important stages in the process of calculating and designing the factory ventilation system is determining the required air flow. Thereby, the new team of engineers can make a suitable design and select equipment that brings high efficiency. Refer to the two popular ways of calculating air flow below.

1. How to calculate the ventilation volume according to the volume of the workshop

Based on the volume of the factory or factory, the enterprise applies the following formula to calculate the air flow:

Tg = X*T

In there:

• X is the number of times the air in the workshop needs to be replaced (times/hour).
• T is the volume of the factory or factory (T = DxRxC), (m3).
• Tg is the total required ventilation volume for the factory (m3/h).

2. How to calculate the factory ventilation volume based on the number of people

How to calculate the second factory ventilation system flow based on the number of workers working in the factory.

In Vietnam, the government stipulates that each worker needs to provide 20m3 of fresh wind in an hour. Therefore, the amount of fresh air to be supplied to the factory is calculated by applying the formula:

Tg = N*20

In there:

• N is the number of employees working in the factory (N = Area/0.7).
• Tg is the total required ventilation volume for the workshop (m3).

The formula for calculating the design of the factory ventilation system

After calculating the amount of wind to provide, the enterprise calculates the design of the fan system, ventilation pipe and the number of Cooling Pads in the factory accordingly. Here are 3 formulas and calculations for factory ventilation that you can use to find the above values.

1. How to calculate the number of factory ventilation fan equipment

Determining the number of fans to use is an indispensable step in the design calculation of the factory ventilation system. When determining the exact number of factory ventilation equipment needed, businesses can measure costs quickly. The simple calculation formula is as follows:

M = Tg/Q

In there:

• Tg is the total amount of fresh air to be supplied to the factory (m3/h).
• Q is the wind flow of the fan unit (m3/h).
• M is the number of exhaust fans required.

2. Calculation formula for factory ventilation pipe design

Currently, to calculate and design the factory ventilation pipeline system, businesses can use many different ways, but in general, the ways are reduced to the method below.

Step 1: Determine the wind speed of the first pipe section (ω1), then based on the wind flow (L) to calculate the cross-sectional area (f) of that pipe section according to the formula:

f = L/ω

Step 2:  Continue to calculate the wind speed of other pipe sections of the factory ventilation system according to the formula:

p*[(ω1)^2 – (ω2)^2]/2 – p12 = 0

In there:

• ω1:  Wind speed of the first pipe section.
  ω2:  Wind speed of the second pipe section.
• ∑Δp122.:  Total voltage loss calculated from branching point 1 to branching point 2.

Then based on the wind speed and flow of the next section to determine the cross-sectional area of ​​that section:  f2 = L2/ω2.

Step 3:  Repeat the calculation in step 2 until the speed and size of all remaining ducts in the factory ventilation system are determined. The total length of the main pipe is equal to the sum of the lengths of the pipe segments plus the length of the elbow.

3. Formula to calculate the number of Cooling Pads to use

Cooling Pad  is an important part with the role of heat exchanger in the factory ventilation system. To calculate the number of  Cooling Pads  needed to design a factory ventilation system, the following steps should be followed:

Calculate the total area of ​​the Cooling Pad:

S = V*X/9000

In there:

• V is the volume of the workshop (V = DxRxC), (m3).
• X is the number of fresh wind changes.
• S is the total area of ​​the Cooling Pad (m2).

How to calculate the number of fans by area, ventilation fan capacity for the factory

You can refer to how to calculate the total air flow to install the appropriate factory ventilation fan

Step 1  : Calculate the volume of the space:

( V ) =  Length  x  width  x  height

Step 2  : Calculate the total amount of air needed

(  T  ) =  X  x  V  (m3/h)

Where:  X  is the number of air changes.

       V  is the volume of space.

Step 3 : Calculate the number of fans needed for the space.

(  N  ) =  T  /  Q

Where:  T  is the total amount of air required.

               Q  is the air flow of the fan (m3/h).

Instructions for construction and installation of ventilation in the workshop quickly

Normally, it will only take 1 month to install a ventilation system for a 10,000m2 factory. Fast construction time will save you a lot of time and labor costs. Each unit of construction and installation of factory ventilation systems will have different working processes. However, there are basically the following main steps.

Step 1: Receive information from customers

Customers with installation needs request services, costs, and desired type of ventilation. After that, the receiving unit will conduct a factory survey and record the actual characteristics of the project.

Step 2: Make a drawing of factory ventilation, give a quote

Based on the actual information about the surveyed works, the construction unit will sketch, build the installation design and arrange the ventilation system. Then send the factory ventilation system price to the customer.

Step 3: Build detailed 2D and 3D drawings

The construction unit will complete the detailed 2D and 3D drawings and estimate the project completion time. The drawing shows the most intuitive image of the factory and ventilation system after completion, helping business owners easily visualize and evaluate. After the customer agrees with the design, the two parties will sign a service contract.

Construction and installation of ventilation system: The construction unit will arrange and install all kinds of suction and ventilation equipment as shown in the design drawings. Installing an industrial factory ventilation fan is an extremely important step, affecting the ventilation and cooling efficiency of the system.

Measurement and adjustment for project acceptance: After the ventilation system is installed, the project staff will measure and calibrate to ensure the details are accurate and of good quality. best.

Step 4: Acceptance of the project

The project has completed the installation and commissioning process, the construction unit will hand over it to the customer for acceptance.

Warranty after the project: The construction unit continues to monitor and support to solve problems about the ventilation system after it has been put into use.

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