Although energy efficiency appliances have improved dramatically over the past decade, we’re always a little cautious about recommending highly rated energy efficient fridges to our eTool clients, as the main focus is on temperature performance to keep food fresh for longer periods, which can become problematic when looked at a little more closely.
Let’s explain what we mean exactly…some fridges save on energy by having longer “compressor-off cycles”, which causes the temperature inside to fluctuate. Ice-cream is a good indicator of temperature fluctuation, as it can partially melt during the off cycle and then form gritty crystals when it refreezes – we’ve all been there!
Poor uniformity may mean that there is a 3°C average in the fresh food compartment, but more than 5°C in other parts, such as the door shelf. This can result in milk going off much faster than you would expect or are happy about.
In terms of environmental impact, the embodied energy of the food is likely to be at least 10 times more than the energy consumed by the fridge, so sometimes a fridge which is actually less efficient and uses a bit more power can extend the life of food quite considerably, making it the more sustainable option! So what can you do to make a lower rated fridge even more sustainable?
Well, properly ventilated fridges can represent large savings in energy efficient houses and when considered as part of the kitchen design, it’s very simple to achieve. Clever options include sealing the fridge into the cabinets and making use of the cool air and exhaust ducting; the closed space keeps cold air inside and around the fridge, away from the kitchen. The air that becomes hot as it passes through the refrigeration mechanism is drawn either up to the ceiling and exhausted outside the house or over the top of the refrigerator and can be ventilated into an upstairs room such as bathroom or laundry to dry the towels.
The ability to increase the efficiency of a fridge with well designed cabinetry and ventilation is not related to the fridge specification, however, so is something that can be comfortably modelled in life cycle assessments.
In addition to being wary of the energy rating and trying to implement the refrigeration air flow in your home, we would always suggest buying the right sized appliance to suit your needs. A large model with the same star rating as a smaller model uses more energy and generates more Greenhouse Gas, and if you think about it, do you really need a gigantic fridge?
A cool cupboard will keep most of your fruits and vegetables in good nick in most climates, allowing you to choose a smaller fridge. Cool cupboards should be located in the coolest part of the house (usually your kitchen or pantry) and have good airflow in at floor level and out through the ceiling.
We know it’s become a bit of a habit in Australia, but try and think of a way to do without a second fridge to save on both the cost of buying and running it and the environmental impact of its use, manufacture and ongoing running costs can easily exceed the original purchase price of an appliance, so always add the purchase cost and the lifetime running cost together to get a more accurate picture of the total cost of an appliance. For example, a fridge that consumes 1kWh extra per day represents over $800 extra operating costs in a decade, without even considering potential energy price increases.
One last tip – especially if you have kids at home – hang a sign on the fridge door that says ‘Only open when necessary!’ Opening fridge doors only when you need to get something out or put something back in, as opposed to leaving it open whilst your make a sandwich, will save between 5-10% in running costs.
Guest Post written by Henrique Mendonca, LCA Engineer, eTool. For more information about life cycle assessment for buildings, please visit www.etool.net.au