Pump System Calculator

The NCC is a performance-based code, requiring all new buildings to meet minimum performance requirements.

A deemed-to-satisfy approach is the optional pathway for achieving compliance used by this calculator – which applies to Class 2 to Class 9 buildings.

This tutorial demonstrates using the pump system calculator to assist verifying compliance of a building’s heating, cooling and/or ventilation design with the NCC.

The pump system calculator is a non-mandatory guidance tool. It helps you apply the deemed-to-satisfy provisions of Clause J5.7 in NCC Volume One.

The calculator is a Microsoft Excel based tool and can be downloaded from the ABCB website.

Using an example, this tutorial covers the basic function of the calculator to assess a typical pump system.

When you first open the Calculator, you'll notice there's a customised ribbon.

The buttons within the ribbon link to each of the sheets within the Calculator.

The help guide is also available from here.

In order to achieve effective results, the calculator relies on entering accurate information.

Some information will be known by the project engineer, while some will need to be sourced from the pump supplier.

This information needs to be checked and verified against the design documentation for compliance assessment.

Let's step through the seven steps of using the calculator.

Step 1, enter the project information and system descriptions.

When the calculator is opened, the All Systems sheet will appear.

The gold shaded cells are input cells.

Enter the project information into the cells of the first row.

Below that, is the Systems section, where each row represents a separate system within the overall project. This needs to be completed for each pump.

The Calculator defaults to one row, but additional systems may be added by clicking on the plus icon.

Only one system will be active at any given time. The active system is italicised.

You can switch between systems by clicking on the rows, or using the ‘change to’ button on the ribbon.

In this example, a single system will be covered.

Step 2, system characteristics.

Navigate to the summary sheet using the ribbon.

This sheet serves as a hub for system-wide information and results.

You’ll notice the project information is prefilled from the previous step.

Select the system and pump characteristics using the drop down menus.

For the purposes of this example, we’ll select a distributive type pipe system...

…with a variable pump speed…

…and an operating time of 5,100 hours per annum – which shows as ‘more than 5,000’.

Next, enter the pump configuration details in the same way.

For this example, it is not a circulator pump so is considered an ‘other pump’.

The remaining pump characteristics – design, stages and speed – will be filled in later.

Step 3, the pipe details.

Navigate to the pipe details sheet.

This sheet provides two options for evaluating the pipe details – the simple or complex method.

The simple method allows designers, who have pre-calculated their pressure drop, to use this data.

The complex method allows the pressure drop to be calculated by entering the characteristics of the systems.

In this example, we’ll use the simple method.

The simple method requires two pieces of information – the piping diameters, under the piping details heading, and the average pressure drop.

Tick only the pipe sizes which are present in the system…

…and enter your pre-calculated average pressure drop.

In the Piping Summary, the calculator will then show if the entered pressure drop satisfies Clause J5.7 on a component level.

In this example, the red colour indicates that this component does not.

However, it can still form part of a compliant system when evaluated on a system level.

Step 4, pump characteristics.

Returning to the summary sheet, we'll finish entering the information for the first pump from earlier.

This pump is an own-bearing type pump, with a single stage, and a 4-pole speed.

This information was provided by the pump supplier.

Step 5, pump details.

Next, navigate to the pump details sheet.

Like the 'pipes' earlier, for 'other pumps', there are two options – the simple method or alternate method.

The simple method can be chosen if the minimum efficiency index is known.

If not, additional information about the pump’s characteristics will be needed.

In this example, the minimum efficiency index is not known, so the alternate method is selected.

Based on this choice, enter the water flow rate, system head and the efficiency.

And check the result.

This pump does not satisfy Clause J5.7 at a component level. However, it can still form part of a compliant system when evaluated at a system level.

Step 6, assess the results.

Returning to the Summary sheet, the results at the system level are shown.

This system doesn't satisfy Clause J5.7 and requires better energy efficiency.

Suggested ways to achieve this are shown in the Results section.

Alternatively, a different assessment method could be considered.

Let's look at improving the energy efficiency, with a more efficient pump, or changing the pipe specifications, to provide a system that satisfies Clause J5.7.

Using a different pump – first, update the information on the summary sheet to a close-coupled, inline pump, with a 2-pole option.

Returning to the Pump Details sheet, update the efficiency details to suit the new equipment.

At a component level, the green colour indicates that this pump now satisfies Clause J5.7.

The summary sheet now shows that while the pipe component does not satisfy Clause J5.7, due to the pressure drop, the new pump’s efficiency is sufficient to offset this.

Therefore the system now satisfies Clause J5.7 – at a system level.

Step 7, report the results.

The calculator can generate a report summarising the results.

On the ribbon, click ‘Go To Report’ to view it, or ‘Print Report’ to print it.

Remember, this information needs to be checked and verified against the design documentation for compliance assessment.

Further details about the Pump System Calculator – including additional examples – are provided in the Energy Efficiency Volume One Handbook, and other resources from the ABCB website.