Tests reveal huge energy penalties of common faults

Oct 24, 2022
Brett

The most frequent equipment defects and their major effects on energy use will be revealed by a government-led study to quantify the advantages of HVAC&R maintenance.

A preview of the findings was given to attendees at the ARBS 2022 Seminar Program last week by Deepthi Worthing from the Department of Climate Change, Energy, the Environment, and Water. As the crew nears the finish line, Worthing outlined the progress of the research and the findings.

The project’s origins can be traced back to the 2014–2016 evaluation of the Ozone Protection and Synthetic Greenhouse Gas Management Program. Working with industry to create information that better educates equipment owners on the advantages of good equipment installation and routine equipment maintenance was one of the review’s suggestions. This would reduce refrigerant leakage (direct emissions) and energy use (indirect emissions).

Quantifying the advantages of HVAC&R maintenance was crucial to this programme, and this significant task was divided into three initiatives.

First, in order to determine the most prevalent and avoidable flaws in refrigeration and air conditioning equipment, the Expert Group carried out a global desk study. It also attempted to calculate the energy costs associated with these defects.

Leaks, maintenance, and emissions, the ensuing study, was well-received by business when it was released in early 2021. It was discovered that unclean condensers and mechanical problems, dirty evaporators and mechanical problems, and wrong refrigerant charge (over or under owing to refrigerant leakage) were the most frequent failures in HVAC&R equipment.

The study team then set out to gather actual Australian data on defects and energy fines. The Expert Group, Refrigerants Australia, and Grosvenor Engineering Group collaborated closely to analyse a set of the company’s maintenance data that had been anonymized.

Published in late 2021, Air Conditioning Faults – An Australian Analysis confirmed the prevalence of frequent faults that cost equipment owners money in energy costs while also offering insights into the prevalence of faults that do not cost money in energy costs but do cost money to repair and cause service interruptions.

It demonstrated the requirement for the creation of common nomenclature and the use of fault trees in fault reporting. It also made clear the necessity of conducting more targeted inquiries into specific equipment flaws and defects.

The government organised a series of bench tests on typical HVAC&R equipment to better gauge the impact of the most frequent defects as the final component of the quantification puzzle. This testing has engaged both CSIRO and SuperCool Asia Pacific.

A remote walk-in coolroom, a refrigeration display cabinet, a single non-ducted split system air conditioner with an inverter, and a three-phase rooftop package air conditioner without an inverter were among the evaluated devices. Four typical faults—blocked condenser, blocked evaporator, refrigerant undercharge and overcharge, and contaminated refrigerant—were simulated for each piece of equipment.

Even while the findings for all of the equipment haven’t been finalised, some critical figures are now available and they’re fascinating to read.

For the majority of fault test situations, all equipment experienced efficiency losses or increased energy usage. The majority of the tests showed average energy losses of 14–20%. Energy demand is anticipated to rise significantly and there is a chance that equipment failure could occur when multiple faults or maintenance problems coexist in a system.

Some transgressions and the corresponding sanctions stood out. Refrigerant contamination in walk-in coolrooms at 20% led to an increase in energy use of up to 69.1% above the baseline test.

Condenser blockage at 40% in chilled display cabinets caused an increase in energy use of up to 15.7% over the baseline test.

Additionally, a 70% rated refrigerant charge lowered the cooling cycle and heating cycle capacities of non-ducted split AC units by 16.8% and 19.3%, respectively (heating cycle). Additionally, cooling EER was decreased by 11.5%, while CoP was decreased by 5.8%. (heating). In addition to the 70% rated refrigerant replacement, indoor and outdoor air inlet blockages were examined, and the results showed that the unit’s cooling and heating capacities were lowered by 18.3% and 19.6%, respectively (heating). EER was decreased by 19.6 percent and 13.9% (cooling) (heating).

In the upcoming months, the definitive results are anticipated. When the information is available, it will be utilised to collaborate with business to create a programme to enhance awareness of the advantages of routine maintenance in both businesses and families.