DR AS/NZS 5141:201X: Standards keep a cool head
Standards Australia has released a new draft version of the proposed Standard covering residential climate control systems. Adelle King reports
Standards Australia has released another draft version of DR AS/NZS 5141:201X Residential climate control systems –Minimum applications and requirements for energy efficiency, performance and comfort criteria.
The draft Standard sets out the requirements for the design, selection, installation, commissioning and maintenance of residential climate control, heating, cooling and air conditioning systems. It aims to maximise the energy efficiency of these systems, as well as the safety and comfort of building occupants.
“The draft Standard seeks to guide the application of vapour compression air conditioning and heat pump systems for residential air conditioning,” says a spokesperson for Standards Australia.
“The purpose of the Standard is to specify minimum requirements for the design, selection, installation, commissioning and maintenance of residential climate control heating, cooling and air conditioning systems. The purpose of these requirements is to underpin the existing work in energy efficiency associated with residential air conditioning.”
According to the Climate Council of Australia, Australia’s 2017/2018 summer was the second hottest on record, while the 2016/2017 summer broke 205 weather records and saw extreme weather events of all types across the country. As this extreme weather becomes more frequent, particularly heat waves and record high temperatures, air conditioning units are coming under increasing pressure and demand.
Poor sizing, faulty installation, poor service procedures and inadequate maintenance can affect the performance and efficiency of air conditioning systems, putting additional strain on electricity systems already at ‘peak demand’ on hot days.
Despite this, there are currently no Australian standards covering correct installation, sizing and on-going maintenance for residential air conditioners. There are best practice guidelines in place for air conditioning suppliers and installers but no Australian standards that offer consumer protection.
The Australian Institute of Refrigeration, Air conditioning and Heating (AIRAH) was concerned about this and in 2010 proposed the development of a new Australian standard to cover the full requirements of residential air conditioning systems.
“There is all this work being done addressing minimum energy efficiency performance standards (MEPS) but all the benefits of having efficient equipment can be lost due to poor installation and poor sizing,” says AIRAH executive manager of government relations and technical services Phil Wilkinson.
According to AIRAH’s report, Future of HVAC – in a net-zero world, there hasn’t been much attention given to improving the efficiency of heating, ventilation and air conditioning (HVAC) systems in residential buildings until now. The report states that between 2005 and 2015, building energy intensity only improved 5% across the residential sector. This is despite Australian households being directly responsible for approximately one fifth of the country’s greenhouse gas emissions, according to the Department of Environment and Energy. As stated on the Australian Government’s Your Home website, heating and cooling account for 40% of household energy use so regulation to improve the efficiency of residential climate control is overdue.
As a signatory to the Paris Climate Change Agreement, Australia has committed to the global transition to net-zero emissions and to reaching net-zero emissions nationally by around 2050. AIRAH believes net-zero buildings, which produce more energy than they use, will help achieve this and are therefore the future.
However, for these buildings to become reality, HVAC systems will need to be more efficient and targeted to occupant needs.
This is where DR AS/NZS 5141:201X could have a significant impact.
In 2015, AIRAH and a range of industry and government organisations began working with Standards Australia to develop the new Australian standard DR AS/NZS 5141:201X, specifically covering the installation of residential climate control systems.
Although residential air conditioning units have been subject to MEPS since 2004, these target the equipment only, while DR AS/NZS 5141:201X also covers selection and installation.
“Both over-sizing and under-sizing occur regularly within the residential sector and there is a view that current practice in this area does not adequately address accurate unit sizing,” says the spokesperson for Standards Australia.
“Over-sizing and misapplication of residential air conditioning units is a barrier to improving system operating energy efficiency and reducing residential electrical demand. Accurate sizing of the air conditioning unit is viewed as critical to the continued energy efficiency operation of systems. Poor design and installation practices can often result in poor overall system efficiency, even when high energy efficiency units are installed.”
The proposed Standard will support existing energy efficiency initiatives, such as MEPS, and demand limiting initiatives for air-conditioning equipment. It is intended to reduce the energy losses that can occur when poor installation of heaters and air conditioners occurs.
“The Standard, in its goal of addressing the quality of residential air conditioning design and installation, is an essential step to fully realise the potential benefits of the existing schemes that address energy efficiency. Without a standard, these potential benefits may not be realised due to poor design and installation practices,” says the spokesperson for Standards Australia.
Since space heating and cooling account for a large portion of household energy use in Australia, the Standard will help to reduce overall energy consumption. It will also address the handling of refrigerants, many of which have a high global warming potential.
DR AS/NZS 5141:201X complements the handbook A guide to good practice for energy efficient installation of residential heating, cooling and air conditioning plant and equipment and is based on deemed-to-satisfy requirements. To meet minimum performance requirements there will be a series of implementation guidelines regarding proper mounting, appropriate air flow around systems and access for maintenance.
“The Standard represents a consumer protection approach, with clients able to refer back to it to ensure their system meets minimum performance and installation requirements. It is a critical first step that provides a national, cohesive outline of what is required of climate control systems design, selection and installation,” says Phil.
The Standard was released for public comment in October 2017 but has since gone through a restructure to bring it into line with the way other standards work. It will now go back out for public comment before it gets published.
Phil says an increase in the number of people interested in the content of the Standard has contributed to the delay in getting it published.
“With the cost of electricity continuing to go up, people are starting to realise how relevant this Standard is going to be and as a result more people are providing comments and feedback. We want to make sure these comments are taken into consideration so that’s why there have been a few restructures.”
Standards Australia says any change to the industry as a result of the draft Standard is not yet clear as the Technical Committee still has work to do before publication.
“Standards Australia will advise industry of the introduction of the Standard when it is published, with comments around any implication it may have on the sector,” says the spokesperson.