WATER TANK SIZING II PLUMBING DESIGN II OVERHEAD DOMESTIC WATER TANK SIZING II FLUSH TANK SIZING II

Introduction

This tutorial provides a comprehensive guide to water tank sizing for plumbing design, specifically focusing on overhead domestic water tanks and flush tank sizing. Understanding how to appropriately size these tanks ensures adequate water supply and system efficiency, which is crucial for any plumbing project.

Step 1: Determine Water Demand

• Assess the total water demand for the building:

  • Identify the number of occupants.
  • Calculate daily water usage per person (common estimates range from 50 to 100 gallons).
  • Factor in additional needs for appliances, gardens, or pools.

• Use the following formula to calculate total daily water demand:

  Total Demand (gallons) = Number of Occupants x Daily Usage per Person
  

Step 2: Calculate Tank Size for Overhead Tanks

• Consider the following factors for sizing overhead tanks:

  • Ensure the tank can hold at least one day's water demand.
  • Include a buffer for peak usage times (15-20% more than daily demand).

• Use this formula for overhead tank capacity:

  Tank Size (gallons) = Total Demand + (Total Demand x Buffer Percentage)
  

• Example Calculation:

  • If daily demand is 500 gallons, and you opt for a 20% buffer:

  Tank Size = 500 + (500 x 0.20) = 600 gallons
  

Step 3: Flush Tank Sizing

• Determine the appropriate flush tank size based on the type of toilets used:

  • Standard toilets typically use 1.6 gallons per flush.
  • Dual-flush toilets may have options for 0.8 gallons (liquid waste) and 1.6 gallons (solid waste).

• Calculate total flush tank capacity:

  • Estimate the number of flushes per day (average is about 5 flushes per person).
  • Multiply the daily flushes by the flush volume.

• Example Calculation:

  • For 4 occupants using standard toilets:

  Daily Flushes = 4 occupants x 5 flushes = 20 flushes
  Total Flush Volume = 20 flushes x 1.6 gallons = 32 gallons
  

Step 4: Other Considerations

• Ensure that the tank is built with appropriate materials to avoid corrosion and leaks.
• Position tanks to minimize the distance water has to travel to reach fixtures, reducing pressure loss.
• Check local regulations and guidelines related to water tank installations.

Conclusion

Proper water tank sizing is essential for efficient plumbing design and ensuring that water demands are met without waste. By following the steps outlined, you can accurately size overhead and flush tanks, ensuring your plumbing system operates smoothly. Next steps might include consulting with a plumbing professional to discuss installation options and maintenance plans.