1. What is an Unvented Hot Water Cylinder Sizing Calculator?

Definition: This calculator determines the appropriate size (in liters) of an unvented hot water cylinder based on the number of occupants.

Purpose: It helps homeowners and plumbers select the correctly sized hot water cylinder to meet household demand without unnecessary energy waste.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Size \) — Recommended cylinder size (liters)
• \( Occupants \) — Number of people in the household

Explanation: The formula allocates 50 liters per person plus a 25-liter base capacity to ensure adequate hot water supply.

3. Importance of Proper Cylinder Sizing

Details: Correct sizing ensures sufficient hot water availability while maintaining energy efficiency and preventing unnecessary heat loss from oversized tanks.

4. Using the Calculator

Tips: Simply enter the number of occupants in the household. The calculator will recommend the appropriate cylinder size in liters.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a +25 in the formula?
A: The additional 25 liters provides a buffer for appliance use and ensures adequate supply even during peak usage times.

Q2: What if we have multiple bathrooms?
A: For homes with 2+ bathrooms, consider increasing the calculated size by 25-50 liters per additional bathroom.

Q3: Does this account for power showers?
A: No, if using power showers you may need to increase the size by 20-30% as they consume more hot water.

Q4: Is this calculation suitable for combi boilers?
A: No, this calculator is specifically for unvented cylinder systems. Combi boilers don't require storage cylinders.

Q5: How does this compare to vented systems?
A: Unvented systems typically require slightly smaller cylinders as they maintain higher pressure and better flow rates.