A collection of historical timetables from the early days of railways in India to the recent past.
These timetables have been generously provided by various IRFCA members. See acknowledgements.
All timetables will open as PDF in a new browser tab. Many files are large (~50MB), please allow time to load.
Length, width, height, and total square footage of each zone. Occupancy: Number of people regularly using the space.
Where: ΔP = pressure drop (Pa) f = friction factor L = duct length (m) ρ = air density (kg/m³) v = air velocity (m/s) D = duct diameter (m) A = duct area (m²) Q = airflow (m³/s)
Ultimate Guide to Using an HVAC Calculation Excel Sheet Accurate sizing prevents equipment short-cycling, high energy bills, and poor humidity control. An streamlines this complex process into an automated, step-by-step workflow. 🛠️ Essential Components of an HVAC Excel Sheet hvac calculation excel sheet 2021
Standard Excel sheets treat a home or building zone as a single thermal block. For complex multi-story properties with independent thermal controls, execute separate spreadsheet worksheets for each individual zone.
Specialized formulas for moisture gain from fresh air, occupant humidity, and equipment. Sizing & Airflow: Length, width, height, and total square footage of each zone
Excel sheets have become a widely accepted tool for HVAC calculations due to their flexibility, ease of use, and widespread availability. Some benefits of using Excel sheets for HVAC calculations include:
Whether you are a professional mechanical engineer, a field technician, or a diligent property owner, leveraging an can streamline your design workflow. This comprehensive guide details the mathematical foundations of these tools, how to use them, and why they remain relevant for modern system design. The Core Science Behind HVAC Load Calculations An streamlines this complex process into an automated,
Using the Darcy-Weisbach or Altshul-Tsal equations, a 2021 sheet automates:
By 2021, the benefits and limitations of these spreadsheets were well-understood by the engineering community.
Where: Q = heat loss (kW) U = overall heat transfer coefficient (W/m²K) A = area (m²) ΔT = temperature difference (°C) V = infiltration rate (m³/s)
These sheets allow users to handle both sensible and latent heat loads, ventilation, and fresh air calculations efficiently. Core Components of a 2021-Ready HVAC Excel Sheet
More historical timetables can be found on the IRFCA Photo Gallery.