SUPPLEMENTARY AIR CONDITIONING SYSTEM SIZING FOR THE AUSTRALIAN MARKET

The term "supplementary air conditioning unit" in the context of building air conditioning system typically refers to an additional cooling and/or heating system installed in a building to supplement the base building's air conditioning system.

Here's a breakdown of some of the relevant concepts:

Base Building Air Conditioning System: This is the main air conditioning system installed in a building that provides cooling/heating and ventilation to the common areas and individual spaces within the structure. It is usually designed to meet the basic requirements of the occupants and complies with the local building codes and standards (NCC in case of Australia).

Supplementary Air Conditioning Unit: This is an additional cooling/heating unit that is added to supplement the base building air conditioning system. Supplementary units are typically installed to meet specific requirements, such as cooling a Comms room or a newly added boardroom within the building that may have needs beyond what the base system can provide.

In commercial real estate, tenants may have unique cooling and heating needs that go beyond the capabilities of the base building system, especially in spaces that house equipment or occupants emitting significant heat. In such cases, the installation of supplementary air conditioning units would be required. The terms of the lease might specify the parameters of the "allowance" for this supplementary air conditioning, dictating who is responsible for the cost, maintenance, energy consumption, etc.

SUPPLEMENTARY AIR CONDITIONING SYSTEM DEFINITION BY NABERS: A supplementary air-conditioning system is an airconditioning system, that is physically independent of and distinguishable from the normal base building air-conditioning system, that has been added in order to service a specific load requirement arising from the nature of occupant usage.

Supplementary air conditioning is a specific arrangement that ensures the additional cooling needs are met without overloading the existing system or violating building codes and regulations.

To size a supplementary air conditioning system, minimum three parameters are required:


• Cooling demand

• Heating demand (due to additional outside air)

• Outside air requirements 


True Partners Consulting Engineers introduces a unique online solution for Supplementary AC Calculations. This user-friendly online tool is a standout in the Aussie building services sector, being the only free tool of its kind. It’s crafted to make the process of calculating supplementary air conditioning requirements more straightforward and simpler.


TRUE PARTNERS SUPPLEMENTARYAC CALCULATOR

 

What distinguishes this calculator is its extensive coverage of calculation data for most major Australian cities. This aspect ensures that users throughout Australia can access precise, localised information suited to their unique needs.


Additionally, the calculator is exceptional in its capability to determine the air filter efficiency grade requirement. This feature is especially vital for minimising the use of outside air, in line with the AS1668.2 – 2012 standards. It's not just about complying with national regulations; it also supports energy efficiency and environmental stewardship.


In sum, True Partners Consulting Engineers’ Supplementary AC Calculator is an innovative tool that provides accurate, easy-to-operate, and region-specific calculations, essential for professionals in the Australian building services industry.

 

Please refer below worked example:


What is the supplementary cooling / heating demand and outside air requirement for a 14 PAX board room with internal area of 35sqm located on floor 18 of a commercial building in Melbourne CBD? We know that the boardroom will be used for periods longer than 30 minutes and base building allowance is 10L/s/person O/A with a density allowance of 1 person/10sqm.


Answer from the True Partners Consulting Engineers online calculator:

2,900 Watts Cooling / 2,100 Heating / 80L/s outside air with F5 grade air filter 

Traditionally, a building services engineer might spend 15 to 30 minutes calculating the required equipment size. With this advanced calculator, however, they can now obtain accurate results in less than a minute. This significant time-saving tool not only streamlines the workflow but also enhances precision, marking a substantial improvement in efficiency for the industry