Natural Gas Demand Apartments

Overview

Engineering reference data for Natural Gas Demand Apartments in combustion engineering.

Key Formulas

Heat Release

$Q = \dot{m} \cdot HV$

Fuel energy release rate.

Air-Fuel Ratio

$AF = \frac{m_{air}}{m_{fuel}}$

Mass of air per mass of fuel.

Excess Air

$EA = \frac{O_2}{21 - O_2} \times 100\%$

From flue gas oxygen measurement.

Variables

Unit Conversions

The natural gas demand calculations can be expressed in two common units:

• Cubic feet per hour (cfh): Standard imperial unit.
• Cubic meters per hour (m³/h): Standard metric unit.

Conversion Factor:

$$1 \text{ m}^3/\text{h} \approx 35.3147 \text{ cfh}$$

To convert a flow rate from m³/h to cfh, multiply by 35.3147. To convert from cfh to m³/h, divide by 35.3147.

Gas Demand Formula

The total hourly gas demand for a building with multiple apartments is calculated by summing the demand from all individual appliances and fixtures.

Primary Formula:

$$Q_{\text{total}} = \sum (N \times Q_{\text{appliance}} \times F_{\text{diversity}})$$

Where:

• $Q_{\text{total}}$ = Total building gas demand (in cfh or m³/h).
• $N$ = Number of each specific appliance type.
• $Q_{\text{appliance}}$ = Rated gas consumption of a single appliance (cfh or m³/h).
• $F_{\text{diversity}}$ = A factor (≤ 1.0) accounting for the probability that all appliances operate at peak load simultaneously.

References

• Original Source