The water capacity of a boiler can be calculated from the boiler's power output (BTU), which is dependent on house size and insulation. Engineers normally use a typical formula to calculate the BTU and water capacity needed for a boiler but this is not an accurate estimate. Standard formulas normally calculate a water output too powerful for the house or, in the worse case, too low. An inaccurate estimation of boiler water capacity will result in boiler inefficiently and wasted resources.
Things You'll Need
- Measuring tape
Measure each room of your house in cubic feet. Use a measuring tape to calculate the width, length and height of each room and multiply these figures together. Note down all the room sizes separately.
If your manufacturer has left the individual power output for your radiators you can also add those figures together rather than measuring each room. You can skip to step 5 if you have the power output for your radiators.
Calculate the estimated BTU by noting down each room type, the amount of windows and type of windows in each room. Measurements for lounges and dining rooms should be multiplied by 5, bedrooms by 4 and kitchen areas by 3. Add 15% of the total to each calculation for rooms facing north, add 20% for rooms with French windows and deduct 10% for rooms with double gazed windows.
Add the individual room calculations together. This will give you the approximate BTU boiler output for the house rather than a standard engineer BTU output.
Divide the BTU by 10,000 and multiple by 4. This will calculate the estimated water capacity in gallons for your boiler -- for example, a home with a 50,000 BTU output would require 20 gallons of water.
Tips & Warnings
- You can use online BTU calculators (see resources) which will allow you to add other factors to the calculation (such as wall insulation and the average temperature of your area).
- Photo Credit white radiator image by Ekaterina Sidorenko from Fotolia.com
How to Size Hot Water Baseboard Heaters
A hot water baseboard heater uses radiated heat from heated water to warm a room. Essentially, hot water baseboard heaters work the...
How to Calculate the Size of Your Boiler
Calculating your boiler size is a challenging process. You can find the size of your existing boiler on the boiler's nameplate. However,...
How to Choose a Central Heating Boiler
A central heating boiler can provide warmth to your whole house, warming everything from the water to the rooms, and ultimately the...
How to Calculate the Efficiency of a Water Tube Boiler
Calculating the efficiency of any appliance is sensible if you want to get a handle on the energy footprint of your home...
How to Calculate Boiler Steam Flows
Modern steam boilers create easily utilized energy for many heating, processing, and mechanical and electrical power-generation applications. They can derive their incoming...
How to Tell What My Radiator Coolant Capacity Is
Knowing what your radiator coolant capacity is can mean the difference between keeping your engine at a safe operating temperature and overheating....
How to Size a Hot Water Boiler
Every aspect of installing a custom boiler must be sized appropriately for the house it will service. This includes the size of...
Boiler BTU Calculations
BTU stands for British Thermal Unit. Traditionally, one British Thermal Unit equals the amount of heat required to raise the temperature of...