Making Air-Duct Calculators

Calculadoras de conductos de aire son herramientas muy útiles para utilizar al dimensionar el conducto. Puede utilizar estos cálculos para encontrar el tamaño de conducto adecuado según los CFM o FPM. Los cálculos también hacen que sea muy fácil encontrar el equivalente cuadrado de un conducto redondo o el equivalente redondo de un conducto cuadrado.

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Fórmulas de tamaño de conductos de aire

Utilice la siguiente fórmula para dimensionar un conducto para el CFM adecuado:
CFM = Área * FPM

Ejemplo: conducto 12 * 12 a 750 FPM; 12 * 12 = 1 pie cuadrado.
1 pie cuadrado * 750 pies por minuto = 750 pies cúbicos por minuto

Utilice la siguiente fórmula para cambiar la forma de un conducto de redondo a cuadrado:
Área de un círculo = πr²
Área / largo = ancho

Ejemplo: convierta un conducto redondo de 12 ″ en un cuadrado de 10 ″ de profundidad o
conducto rectangular.

Área de un círculo de 12 IN de diámetro = π6² = 113 IN cuadrados (redondeado)
113/10 = 11,3
Un conducto redondo de 12 ″ = conducto rectangular de 10 * 11,3. Utilice un 10 * 12
conducto rectangular.

Utilice la siguiente fórmula para cambiar la forma de un conducto de cuadrado a redondo:
2(raíz cuadrada [área / π]) = diámetro

Ejemplo: Convertir un conducto cuadrado de 10*10 en un redondo equivalente
conducto.
Área = 10 * 10 = 100 pies cuadrados EN
2(raíz cuadrada [100/3,14159]) = 2(raíz cuadrada [31,83])
= 2(5,6418) 5 11,28

Un conducto cuadrado de 10 * 10 = conducto redondo de 11,28 ″. Utilice un estándar
Conducto de 12″ de diámetro.

Pautas para el tamaño de los conductos

Calcule el área de un cuadrado o un rectángulo usando (largo * ancho).

Calcule el área para la ronda usando (π * radio²).

Al calcular los tamaños de los conductos, recuerde que los conductos no se fabrican en forma redonda de 11,5" o rectangular de 12,375" * 14,24" como estándar, por lo que debe redondear al número par más cercano para un tamaño, lo que da como resultado una ronda de 12" y una de 12 *. 14 conducto rectangular.

Siempre que se cambie el tamaño de un conducto del tamaño indicado en el diseño del ingeniero, debe ser con la intención de mejorar la constructibilidad. Siempre que sea posible, es recomendable utilizar el diseño del ingeniero a menos que no pueda hacerlo debido a las condiciones del campo. Si las condiciones de campo no permiten un tamaño diseñado, entonces deberá escribir una solicitud de información (RFI) para informar al ingeniero sobre el cambio que se está realizando.

FREQUENTLY ASKED QUESTIONS

What are the benefits of using air-duct calculators in HVAC system design?

Air-duct calculators provide a quick and accurate way to size ducts based on CFM or FPM, ensuring that the ductwork is properly sized for the HVAC system. This helps to prevent issues such as inadequate airflow, increased pressure drops, and reduced system efficiency. By using air-duct calculators, designers and engineers can also easily convert between round and square duct shapes, making it easier to design and install ductwork that meets the specific requirements of a building or application.

How do I choose the right formula for sizing a duct based on CFM or FPM?

To choose the right formula, you need to determine whether you are working with CFM (cubic feet per minute) or FPM (feet per minute). If you know the CFM, you can use the formula CFM = Area x FPM to calculate the required duct size. If you know the FPM, you can rearrange the formula to solve for Area. It’s essential to understand the relationship between CFM and FPM to ensure accurate duct sizing.

What is the significance of the πr² formula in air-duct calculations?

The πr² formula is used to calculate the area of a circle, which is essential for converting between round and square duct shapes. In the context of air-duct calculations, this formula allows you to calculate the area of a round duct based on its diameter. This value can then be used to determine the equivalent square or rectangular duct size, ensuring that the ductwork is properly sized for the HVAC system.

How do I account for duct fittings and transitions when using air-duct calculators?

Duct fittings and transitions can significantly impact airflow and pressure drop in an HVAC system. When using air-duct calculators, it’s essential to consider the effects of these components on duct sizing. You can do this by using fitting loss coefficients or equivalent lengths to account for the added resistance in the ductwork. This ensures that the duct size is adequate to handle the increased pressure drop and maintain proper airflow.

Can air-duct calculators be used for both residential and commercial HVAC systems?

Yes, air-duct calculators can be used for both residential and commercial HVAC systems. The formulas and calculations remain the same, regardless of the application. However, commercial HVAC systems often require more complex ductwork designs and larger duct sizes, which may necessitate more advanced calculation methods or software tools. In either case, air-duct calculators provide a fundamental understanding of duct sizing principles and can be used as a starting point for more detailed designs.

Are there any limitations or assumptions to consider when using air-duct calculators?

Yes, air-duct calculators are based on idealized conditions and assumptions, such as uniform airflow and negligible friction losses. In reality, ductwork is subject to various sources of pressure drop, including fittings, transitions, and surface roughness. Additionally, air-duct calculators may not account for factors like duct leakage, thermal expansion, or acoustic considerations. It’s essential to understand these limitations and consider them when applying air-duct calculator results to real-world HVAC system designs.