Refrigerant based HVAC systems have typically used chemical refrigerants for heat transfer.
Some refrigerants, such as R22, are hydrochlorofluorocarbons (HCFC’s) which damage the ozone layer. Others, such as R410A and R32 are hydrofluorocarbons (HFC’s) which are potent greenhouse gases. In fact, one kilogram of R410A has the same greenhouse impact as two tonnes of carbon dioxide. This is the equivalent of running your car for six months.
Refrigerants leak into the atmosphere from faulty or ageing equipment. The phase out of HCFC’s (i.e. R22) commenced in 1990 and finished in 2015. They are no longer permitted to be imported into Australia. The Australian Government started the phase down and phase out of bulk hydrofluorocarbon (HFC’s i.e. R410A and R32) imports in 2018 in accordance with the Montreal Protocol global agreement. As the HFC’s are phased out, their cost will increase.
These chemical refrigerants suffer many limitations, including:
You can replace chemical refrigerants with natural refrigerants such as ammonia, carbon dioxide or hydrocarbons. These are the most energy efficient and environmentally safe refrigerants.
There is a shift away from chemical refrigerants and growing pressure to accelerate this change. For instance, The international Consumer Goods Forum, comprising 400 of the world’s largest companies, is calling for the use of natural refrigerants exclusively in all HVAC and refrigeration applications.
The parties to the Montreal Protocol stated that Natural Refrigerants are “the most cost effective and tangible global measure to address climate change”.
High efficiency domestic refrigerators already use a natural refrigerant (R600A) to meet MEPS minimum energy performance standards and to achieve a higher efficiency star rating. There is an estimated 700 million domestic refrigerators globally using natural refrigerants.
A fundamental reason to switch to natural refrigerants is for the electricity cost savings. Hydrocarbon refrigerants are approximately 50% more efficient conductors of heat than fluorocarbon refrigerants and their operating pressures are 20-35% lower than that of fluorocarbon refrigerants. These lower operating discharge pressures reduce the work that the compressor has to do thus reducing wear and tear and electricity consumption. There is less pressure on pipe work, joints, hoses, fittings etc, reducing the likelihood of leaks. This extends the working life of your equipment.
When changing refrigerant we take into account that refrigerants are flammable, particularly with the mixing of oil, and ensure appropriate application. The volume of refrigerant used in an enclosed building space needs to adhere to regulatory levels. We fit gas sensors to all HVAC or refrigeration units that contain more than 1kg of hydrocarbon refrigerant, to isolate the power in the event of a leak. This ensures best practise safety. Hydrocarbon refrigerants have the identical flammability classification as the latest chemical refrigerant, R32.
To summarise, the benefits of natural hydrocarbon refrigerants over chemical refrigerants include: