Boiler Sizing Calculator

Introduction

You can use this page to help estimate the size of boiler suitable for your needs.

Before proceeding please read the instructions on this page to familiarize yourself with how to use this calculator. When you're ready please click on the 'Start Boiler Sizing Calculator' button.

Disclaimer

The Biomass Boiler Sizing Calculator is provided to help give you an idea of the size of boiler you are likely to need. The results are not perfect and make assumptions that may not be correct for your particular requirements.

If you are thinking of investing in a Biomass Boiler system we strongly recommend that you contact us to discuss your requirements and get a more detailed and accurate assessment of the best solution for you.

While every effort has been made to make this calculator accurate neither Asgard Biomass Systems or R D Associates Ltd. can accept any responsiblity for losses incurred following the advice provided by this tool.

Instructions

In order to use this calculator you need to divide the building(s) you want to heat into logical blocks. Each block needs to be square (or rectangular) and you should ignore any loft conversions or roof spaces. The diagrams below should make this clear.

For each block you will need the following information (described in more detail in following sections):

1. Depth in metres
2. Width in metres
3. Room height in metres
4. Number of Floors
5. Number of external walls along the depth
6. Number of external walls along the width
7. Number of heated blocks that are directly above or below
8. Total window area in square metres
9. Type of window
10. Type of wall construction
11. Type of roof construction
12. Area of the country

When you have this information you can click on the 'Start Boiler Sizing Calculator' button and you will see the following window:

Enter the information for the first building block (use the description field at the top of the window to give the block a descriptive name, such as 'Office').

Click on the 'Save' button to save that block. You will see that the main page now displays a table similar to the following:

Add each building block in turn to calculate the total boiler capacity required.

This calculator makes the assumption that 20% of your requirement is needed for hot water. This is a very general average and may not be correct for your requirements.

Biomass boilers vs 'conventional' gas/oil fired boilers

You will see from the results that are given that a smaller biomass boiler is required compared to the more traditional oil or gas fired one (we give both figures in the results table).

The smaller sized boiler is required to compensate for the different mode of operation that biomass boilers have. Generally they are run continuously at a lower heat setting as compared to the on/off flash heating of oil and gas boilers.

Depth

The internal distance, in metres, from the front of the building block to the back.

Width

The internal width, in metres, of the building block.

Room height

The internal height of the floors in metres.

If the various floors in a block have different heights it is advised that you divide this into smaller sub-blocks, perhaps one for each floor.

Number of floors

The number of floors within the building block.

This may not be the same as the number of floors in the building if it has been subdivided into smaller blocks.

Number of external walls along the depth

The number of walls at the sides of the block that are either external or adjacent to buildings/blocks that have no heating.

Where an adjacent block is smaller a partial figure should be given.

(for example, in the diagram above the annex is only ¹/₄ of the size of the office. In this example the office has 1 ³/₄ external walls along the depth.

Number of external walls along the width

The number of walls at the front and back of the block that are either external or adjacent to buildings/blocks that have no heating.

Where an adjacent block is smaller a partial figure should be given.

Number of heated blocks above or below

Whether heated blocks/buildings are either directly above or directly below this one.

Window Area

The total window surface area in square metres for this block.

Type of window

The type of window and frame installed in this block.

Type of wall construction

The type of wall construction used for this block.

Type of roof construction

The type of roof construction used for this block.

Area of the country

The area of the country that this building is in (should be the same for each block).