When I first discuss an air-supported membrane project with a customer, I usually start with one simple question: what does the fan need to do every day, not just on the first day of operation? For a foundation pit air-supported membrane, the answer is quite important. The membrane needs a steady supply of air to maintain its shape and internal pressure, so the fan is not just another ventilation device. It is part of the system that keeps the whole structure working.

At Zhejiang Shangyang Industrial Fan Co., Ltd., we manufacture the Special Centrifugal Fan for Foundation Pit Air-Supported Membrane for projects that need stable and continuous air supply. We focus on centrifugal fan technology, and our factory produces both standard and nonstandard industrial fans. Over the years, our team has worked with customers in air-supported membrane systems, environmental protection, coating, boilers, kilns, dust collection, thermal energy, chemical processing, cement, food processing, and other industrial applications.

Our sales, engineering, and manufacturing teams have around 20 years of industry experience. That experience has taught us something very practical: a fan should be selected according to the actual system rather than simply according to a product name.

For an air-supported membrane over a foundation pit, the fan needs to provide the right amount of air at the required pressure. It also needs to operate reliably for long periods, fit the available installation space, and allow reasonable maintenance. Depending on the project, noise, temperature, weather conditions, power supply, and backup requirements may also need to be considered.

In this article, I will explain how we look at this type of fan, how the system works, what features matter, where the fan can be used, how we manufacture it, and what customers should prepare before asking us for a quotation.

1. What Is a Foundation Pit Air-Supported Membrane Fan?

A Special Centrifugal Fan for Foundation Pit Air-Supported Membrane is a centrifugal air supply fan designed for an air-supported membrane structure covering or enclosing a foundation pit. Its main job is to provide a controlled and continuous supply of air so that the membrane can maintain the pressure needed to stay in its designed shape.

The idea is quite simple. Unlike a traditional building, an air-supported membrane does not depend on a heavy steel roof to support the entire covering. The internal air pressure helps support the membrane. The fan supplies air continuously to compensate for normal air leakage through doors, openings, joints, and other parts of the structure.

This means the fan is closely connected to the stability of the membrane system.

We therefore look at more than the fan motor when designing or selecting this type of equipment. We consider the size of the membrane structure, the enclosure arrangement, the required internal pressure, air leakage, door operation, weather conditions, duct layout, and the expected operating schedule.

A foundation pit air-supported membrane fan may also be required to work for long periods without interruption. In some projects, the fan operates continuously because the membrane must maintain pressure throughout the day and night.

This is why reliability is one of the first things we consider.

Why the Fan Matters So Much

People sometimes think the membrane itself is the most important part of an air-supported structure. In practice, the membrane and air supply system need to work together.

If the air supply is too low, the internal pressure may not remain at the required level. If the pressure is too high, the system may not operate as intended and unnecessary energy may be consumed. The fan therefore needs to match the actual system requirements.

For us, the correct approach is to understand the complete operating condition before confirming the fan.

2. How Does an Air-Supported Membrane Fan Work?

The working principle is easier to understand than it may sound.

The centrifugal fan takes air from the surrounding environment and sends it into the membrane structure. The air enters through the fan inlet, passes through the rotating impeller, and gains energy. The fan casing then guides the air toward the outlet and into the air supply system.

The supplied air increases and maintains the internal pressure of the membrane structure.

Because the membrane is not completely airtight, some air naturally escapes. Doors may also be opened and closed during normal use. People, vehicles, and equipment may enter the structure. Every opening can change the amount of air the system needs.

So the fan must provide enough airflow to compensate for these normal losses while maintaining the required internal pressure.

1. Outdoor air enters the centrifugal fan.

2. The impeller rotates and transfers energy to the air.

3. The fan produces the required airflow and pressure.

4. Air travels through the supply duct or connection system.

5. The air enters the air-supported membrane structure.

6. Internal air pressure helps support the membrane.

7. The fan continues supplying air to compensate for normal leakage.

This continuous process is why we normally treat an Air-Supported Membrane Centrifugal Fan as an important operating component rather than an ordinary temporary blower.

Airflow and Pressure Are Both Important

When a customer tells us, “We need a fan for a large membrane,” that is not enough information for technical selection.

We need to know how much air is required and how much pressure the fan must provide. These two values are related but they are not the same thing.

Airflow describes how much air moves through the system. Pressure describes the force available to move that air through the system and overcome resistance.

Ducts, filters, bends, dampers, air distribution components, and other equipment can create resistance. The fan must be selected to match the complete system rather than only the membrane volume.

Source: Zhejiang Shangyang Industrial Fan Co., Ltd. fan selection and application experience, combined with general air-supported structure operating principles. Actual fan requirements must be confirmed from the specific membrane system.

3. Main Features of Our Special Centrifugal Fan

When we manufacture a Special Centrifugal Fan for Foundation Pit Air-Supported Membrane, we focus on stable air supply first. The fan does not need to look complicated. What matters is whether it can provide the required airflow and pressure and continue doing so reliably.

Stable Continuous Air Supply

The most basic requirement is continuous air delivery. The fan should be able to support the membrane system during normal operation rather than only work well for a short period.

For projects where the membrane needs to remain inflated around the clock, the motor, bearings, impeller, shaft, and other components need to be selected with the operating schedule in mind.

Reliable Centrifugal Structure

The centrifugal design is suitable for many industrial air supply applications because it can provide useful pressure while maintaining controlled airflow.

We manufacture different centrifugal fan configurations, so the final structure can be discussed according to the customer's airflow, pressure, installation, and operating requirements.

Low-Noise Operation Options

Some foundation pit projects are located close to residential areas, offices, construction management areas, or other noise-sensitive locations. In these cases, fan noise may become a practical issue.

Noise can come from the motor, impeller, airflow turbulence, vibration, and connected duct system. Depending on the project, suitable fan selection, vibration control, or additional acoustic measures can be considered.

Flexible Configuration

Not every foundation pit has the same layout. Some projects have limited space. Others require a particular air outlet direction or connection arrangement.

Because our factory produces both standard and nonstandard industrial fans, we can discuss different configurations according to the installation requirements.

Suitable for Long-Term Operation

Air-supported membrane systems often need the fan to run for long periods. We therefore pay attention to the operating schedule when discussing motor and mechanical components.

Continuous operation also makes routine inspection important. Bearings, belts where applicable, electrical connections, impeller condition, and vibration should be checked according to the actual equipment and maintenance plan.

Practical Maintenance

A fan may operate reliably for a long time, but maintenance is still part of industrial equipment management. We prefer a structure that allows customers to inspect important components without creating unnecessary work.

4. Technical Factors We Consider Before Fan Selection

One of the most common mistakes in fan purchasing is starting with the fan model instead of the operating condition.

When a customer contacts us about a foundation pit membrane fan, we normally want to know several basic things.

1. Membrane Size

The length, width, height, or approximate enclosed volume gives us an initial understanding of the project.

However, membrane size alone does not determine the fan. Leakage, door size, door frequency, structure shape, and required internal pressure also matter.

2. Required Internal Pressure

The membrane system normally has a specified working pressure. We need this information to understand the fan pressure requirement.

The actual value should come from the membrane system design rather than being guessed by the fan manufacturer.

3. Air Leakage

No practical air-supported structure is perfectly sealed. Doors, access points, seams, and other areas can allow air to escape.

The fan needs enough capacity to compensate for this normal loss.

4. Door Operation

This is particularly important for foundation pits used as construction or industrial working areas. Large vehicle entrances or frequently used access doors can create temporary air losses.

If the doors open often, the air supply requirement may be higher than that of a structure that remains closed most of the time.

5. Installation Location

We need to know whether the fan will be installed indoors, outdoors, beside the foundation pit, inside an equipment room, or in another location.

Outdoor installation may require additional consideration for weather protection, drainage, electrical protection, and maintenance access.

6. Power Supply

Voltage, frequency, phase, and motor requirements should be confirmed before production.

7. Noise Requirements

If the fan is close to people or residential buildings, the customer should tell us about any site noise requirements at the beginning of the project.

Source: Zhejiang Shangyang Industrial Fan Co., Ltd. project consultation and industrial fan selection experience. These factors are used for technical discussion and do not replace the membrane system designer's specifications.

5. Where Can This Foundation Pit Air-Supported Membrane Fan Be Used?

The most direct application is an air-supported membrane structure covering a foundation pit. However, similar air supply principles can be used in other large membrane structures where stable internal pressure is needed.

Foundation Pit Enclosures

This is the main application for this specialized fan. A membrane can be installed over a foundation pit to create an enclosed working environment while reducing the need for a traditional rigid roof structure.

The centrifugal fan supplies the air needed to support the membrane and maintain the designed internal pressure.

Construction Projects

Large construction sites may use temporary membrane structures to cover working areas, storage areas, or foundation-related spaces.

The fan can provide the continuous air supply required by the temporary enclosure, provided the system requirements match the fan configuration.

Industrial Storage Areas

Air-supported structures can also be used for certain temporary or semi-permanent storage applications. In these cases, the fan may operate for long periods, making energy use and maintenance important.

Sports and Large Membrane Structures

The same basic technology is used in air-supported sports facilities and large indoor membrane structures. However, fan selection should always follow the specific membrane system requirements.

Temporary Exhibition or Work Areas

Some large temporary structures require continuous air supply to maintain their shape. A suitable centrifugal fan can be part of the air supply system.

Agricultural and Industrial Enclosures

Air-supported membrane structures may also be used in selected agricultural or industrial applications. The fan configuration depends on the size and operating conditions of the structure.

Our company has experience in air-supported membrane fan applications as well as other industrial ventilation fields. This wider background is useful because the fan still needs to be treated as an engineered airflow device, even when the final application is a membrane structure.

Source: Zhejiang Shangyang Industrial Fan Co., Ltd. application experience. Actual suitability depends on the membrane structure design, operating pressure, airflow demand, and installation conditions.

6. How We Manufacture the Special Centrifugal Fan

Our manufacturing process begins with technical information rather than metal fabrication.

For a standard industrial fan, the production process can be relatively straightforward. For a specialized foundation pit membrane fan, we first want to understand how the fan will work in the customer's system.

Technical Review

We review airflow, pressure, motor requirements, operating schedule, installation position, inlet and outlet arrangement, noise requirements, and other available information.

If the customer has a system drawing, fan replacement information, previous equipment data, or photographs of the installation, these can be useful during the technical discussion.

Material Preparation

After the fan configuration is confirmed, the required materials and components are prepared.

Material selection depends on the operating environment. A normal air supply application does not necessarily require the same material as a high-temperature or corrosive gas application.

Impeller Manufacturing

The impeller is one of the most important parts of a centrifugal fan. It rotates continuously and directly transfers energy to the air.

We pay attention to blade positioning, welding quality, dimensional accuracy, shaft connection, and balance. Proper balance is particularly important because an unbalanced rotating assembly can create unnecessary vibration.

Casing Manufacturing

The casing guides airflow from the impeller toward the outlet. Its structure needs to match the confirmed fan design and installation arrangement.

Assembly

The impeller, shaft, bearings, motor, transmission components where applicable, casing, base, and other components are assembled according to the specified configuration.

Alignment and assembly condition are checked during the process.

Inspection Before Delivery

Before shipment, we inspect the equipment according to the agreed technical requirements. Depending on the order, this can include appearance, dimensions, rotation direction, assembly condition, operating performance, and accessories.

Our company also possesses multiple national test reports for specialized products and has obtained applicable certifications, including national explosion-proof certification and energy efficiency certification for relevant products.

7. Production Cycle, Delivery, Payment, Transportation and Packaging

For an industrial fan project, the customer normally cares about more than technical performance. Delivery time, packaging, transportation, and payment terms also need to be clear.

Production Cycle

The production cycle depends on the fan model, airflow and pressure requirements, materials, motor configuration, order quantity, customization level, and current production schedule.

Standard configurations can normally be processed more quickly than nonstandard fans. A customized foundation pit air-supported membrane fan may require additional time for technical confirmation, material preparation, manufacturing, assembly, and inspection.

We recommend confirming the main technical parameters before production starts. If the fan requirements change after manufacturing begins, the production schedule may need to be adjusted.

Delivery Standard

Before delivery, we inspect the fan according to the agreed technical requirements. The delivery scope may include the complete fan unit, motor, base, and agreed accessories, depending on the confirmed order.

The exact supply scope should be stated clearly in the quotation and technical agreement.

Payment Method

T/T is commonly used for industrial equipment orders. The deposit, balance, and payment schedule are confirmed according to the commercial contract.

Transportation

For domestic orders, transportation can be arranged by truck or other suitable methods. For international projects, sea freight, rail, truck transportation, or combined logistics can be considered according to the destination and equipment dimensions.

Packaging

Industrial Centrifugal Fans need protection during loading, unloading, and transportation. Depending on the fan size and shipping conditions, we can use protective film, wooden cases, steel frames, or reinforced packaging.

Special attention is given to the motor, impeller, shaft, casing, electrical components, and exposed connections. The final packaging method depends on the product structure and transportation method.

8. Why Choose Zhejiang Shangyang Industrial Fan Co., Ltd.?

When customers purchase a specialized industrial fan, we know they need more than a product catalog. They need someone who understands how the fan will actually be used.

Zhejiang Shangyang Industrial Fan Co., Ltd. is a national high-tech enterprise and a small- and medium-sized technology enterprise. Our sales company is located in Shanghai, China, and our manufacturing factory is located at No. 6-8, Bifa Road, Xinbi Subdistrict, Jinyun County, Lishui City, Zhejiang Province.

Our fan technology design, manufacturing, and sales teams have around 20 years of experience. We have continuously developed and improved our products through practical manufacturing experience and technical development.

Our product range includes centrifugal fans, High-Temperature Fans, induced draft fans, axial fans, Low-Noise Centrifugal Fans, High-Pressure Fans, stainless steel centrifugal fans, hot air circulating fans, mixing fans, and explosion-proof centrifugal fans.

Our products are used in coating, kiln, boiler, environmental protection, dust collection, thermal energy, printing, coating equipment, medical latex equipment, air-supported membrane, separation, cement, chemical, and food industries.

For the air-supported membrane field, our experience with industrial airflow equipment helps us understand that the fan must work together with the membrane, duct, doors, and other system components.

We also understand the importance of nonstandard manufacturing. A foundation pit does not always provide an easy installation environment. Space may be limited, the fan may need a special outlet direction, or the customer may have an existing air supply system that needs to be matched.

In these cases, a standard catalog fan may not be enough. We can discuss a customized configuration based on the actual project information.

Our company follows a practical approach to manufacturing. We take quality as an important part of production and use customer requirements as the basic reference for technical and service work.

9. Frequently Asked Questions About Foundation Pit Air-Supported Membrane Fans

What is a Special Centrifugal Fan for Foundation Pit Air-Supported Membrane?

It is a Centrifugal Air Supply Fan designed to provide stable and continuous airflow for an air-supported membrane structure installed over or around a foundation pit. Its purpose is to help maintain the internal pressure required to support the membrane.

Why does an air-supported membrane need a fan?

The membrane relies on internal air pressure for support. Because the structure is not perfectly airtight and doors or access points may be opened, air is continuously lost. The fan supplies additional air to compensate for these losses.

Does the fan need to operate continuously?

In many air-supported membrane systems, continuous operation is required to maintain the designed internal pressure. The exact operating schedule depends on the membrane system design and control strategy.

How do I select the correct fan?

Start with the membrane size, required internal pressure, expected air leakage, door operation, duct arrangement, and operating schedule. Airflow and pressure are the main fan selection parameters, but installation and environmental conditions should also be considered.

Can you customize the centrifugal fan?

Yes. We manufacture standard and nonstandard industrial fans. Depending on the project, we can discuss airflow, pressure, motor configuration, material, outlet direction, mounting structure, and other requirements.

Can this fan be used outdoors?

It can be configured for suitable outdoor installations, but the environmental conditions should be confirmed before production. Weather exposure, rain protection, temperature, electrical requirements, and maintenance access may need to be considered.

How can I reduce fan noise?

Fan noise can be influenced by speed, airflow, impeller design, vibration, motor operation, ducts, and installation. Depending on the project, suitable fan selection, vibration isolation, acoustic treatment, or a soundproof enclosure can be considered.

Can the fan work with a large foundation pit membrane?

Yes, provided the airflow and pressure requirements can be matched. A large membrane does not automatically mean that one specific fan size is suitable. We need the actual system information before confirming the configuration.

What information should I send for a quotation?

Please provide the membrane dimensions or volume, required internal pressure if available, airflow requirement if already calculated, door dimensions and opening frequency, installation location, power supply, operating hours, noise requirements, and any available drawings.

How long is the production lead time?

The lead time depends on the model, specifications, quantity, motor, materials, customization, and production schedule. Standard configurations can normally be completed faster than customized fans. We confirm the expected delivery schedule after technical requirements are finalized.

How is the fan packaged for export?

Packaging depends on the fan size and shipping method. Protective film, wooden cases, steel frames, and reinforced packaging may be used to protect the equipment during transportation.

What payment method do you normally use?

T/T is commonly used for industrial equipment orders. The specific payment schedule is agreed in the commercial contract.

10. A Practical Approach to Choosing Your Foundation Pit Membrane Fan

After years of working with industrial fans, I have learned that the best fan selection usually starts with a good technical conversation.

For a Special Centrifugal Fan for Foundation Pit Air-Supported Membrane, the key question is not simply “How big is the fan?” The better question is “What does the membrane system need from the fan?”

We need to understand the required airflow, internal pressure, leakage, door operation, duct resistance, installation conditions, operating hours, and environmental requirements. Once these points are clear, the fan configuration becomes much easier to determine.

Our team at Zhejiang Shangyang Industrial Fan Co., Ltd. can work with standard and nonstandard industrial fan requirements. We manufacture centrifugal fans and other industrial ventilation equipment for customers in China and overseas markets.

If you are planning a foundation pit air-supported membrane project, replacing an existing fan, or looking for a customized air-supported membrane centrifugal fan, you can provide the available technical information to us.

We can then review the application from the fan side and discuss the appropriate airflow and pressure range, fan configuration, motor arrangement, installation requirements, production schedule, delivery standard, packaging, and transportation.

For us, the purpose of a good membrane fan is simple: provide the air the structure needs, keep the operation stable, make maintenance practical, and fit the real working conditions of the project.

That is the approach we follow when manufacturing the Special Centrifugal Fan for Foundation Pit Air-Supported Membrane.