How To Calculate CFH

CFH Formula:

\[ CFH = \frac{BTU}{HV \times Eff} \]

Cubic Feet Per Hour (CFH):

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1. What is CFH Calculation?

CFH (Cubic Feet per Hour) calculation determines the gas flow rate required to meet specific heating demands, taking into account the heating value of the gas and the efficiency of the heating system.

2. How Does the Calculator Work?

The calculator uses the CFH formula:

\[ CFH = \frac{BTU}{HV \times Eff} \]

Where:

\( BTU \) — British Thermal Units (required heating capacity)
\( HV \) — Heating Value (BTU per cubic foot of gas)
\( Eff \) — Efficiency percentage of the heating system

Explanation: The equation calculates the volume of gas needed per hour to produce the required BTU output, accounting for the energy content of the gas and system efficiency.

3. Importance of CFH Calculation

Details: Accurate CFH calculation is essential for proper sizing of gas lines, regulators, and heating equipment to ensure efficient and safe operation of gas-fired systems.

4. Using the Calculator

Tips: Enter BTU requirement, heating value of the gas (typically 1000-1100 BTU/ft³ for natural gas), and system efficiency percentage. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical heating value for natural gas?
A: Natural gas typically has a heating value between 1000-1100 BTU per cubic foot, though this can vary by location and gas composition.

Q2: How does efficiency affect CFH requirements?
A: Higher efficiency systems require less gas flow (lower CFH) to produce the same BTU output, as more of the gas energy is converted to useful heat.

Q3: What are typical efficiency values for heating systems?
A: Modern high-efficiency systems can reach 90-98% efficiency, while older systems may operate at 60-80% efficiency.

Q4: Why is accurate CFH calculation important?
A: Proper CFH calculation ensures gas lines and equipment are correctly sized for safe and efficient operation, preventing issues like insufficient heating or dangerous pressure conditions.

Q5: Can this calculator be used for propane or other gases?
A: Yes, but you must use the correct heating value for the specific gas type (propane has approximately 2500 BTU/ft³ heating value).