18-0918 AS 1668.2 Requirements for Equivalence to ASHRAE 62.1 3.x

QUESTION

As per the Healthy Interior Environment Imperative, our project will create a Healthy Indoor Environment Plan that explains how the building will achieve an exemplary indoor environment, including compliance with the current version of ASHRAE 62, or international equivalent.

In Australia, the equivalent standard is called Australian Standard (AS) 1668.2: The use of ventilation and air-conditioning in buildings [AS1668].

The project team’s Services Engineer has reviewed both ASHRAE 62 and AS1668 and can confirm that ventilation rates required in each are equivalent.

For example, in Sales areas (the main occupancy type in our project), the required ventilation rate is 1.17 litres per second per square metre (l/s/m2) in the ASHRAE Standard, and even higher in the Australian standard - at 2.14 l/s/m2 in AS1668.

We have found four areas where ASHRAE 62 has requirements that are not stipulated in either the Building Code of Australia or the Australian Standards. We have listed these below and have stated how these will be addressed to align with ASHRAE 62 as follows:

ASHRAE Reference 5.1.3: Documentation

AS1668 does not have any specific requirements in relation to documentation. To address this, the project team will ensure that the Building Permit design documentation states the assumptions that are made with respect to ventilation rates and air distribution.

ASHRAE Reference 5.5.2 & 5.5.3: Rain Entrainment & Rain Intrusion

AS1668 does not specifically specify the design requirements to manage rain entrainment and prevent rain intrusion. To address this, the mechanical design for the project has been carried out to manage rain entrainment and prevent rain intrusion in line with ASHRAE 62. These will be noted on design documents in the final submission.

ASHRAE Reference 5.5.5: Bird Screens

AS1668.2 does not have any specific requirements in relation to a screening device to prevent bird nesting. To address this, the mechanical services design documentation (specification) nominates vermin proof mesh to be provided, which will achieve the same result.

ASHRAE Reference 5.10: Drain Pans

AS1668 does not have any specific requirements in relation to drain pans. To address this, the mechanical services design documentation includes the requirements for condensate trays beneath all cooling coils to achieve the same result.

We kindly request that the ILFI confirm that the project can use the Australian Standard (AS) 1668.2 as the international equivalent of ASHRAE 62, noting that the project team will address the four differences above as suggested, and include these in the project’s Healthy Indoor Environment Plan.

ANSWER

For purposes of compliance with Imperative 08 Healthy Interior Environment, Australian Standard (AS) 1668.2 plus the requirements specified under ASHRAE 62.1 for:

5.1.3: Documentation (re: ventilation rates, air distribution, air balance testing, and standards for measuring and balancing),
5.5.2 & 5.5.3: Rain Entrainment & Rain Intrusion,
5.5.5: Bird Screens, and
5.10: Drain Pans,

is considered equivalent to the current version of ASHRAE 62 (62.1).