For those looking to be more sustainable in the hotter months of the year, we’ve put together this guide about what might be more sustainable ways to cool your home.
We include information across various aspects of cooling a house (or, preventing it from getting too hot), such as sustainable features that can be useful in the home, energy sources used for fans and air conditioners, individual cooling systems and methods, and more.
1. Consider Wearing Clothing That Keeps You Cool
The first thing you might consider in hotter weather is the clothing you’re wearing around the house
Wearing cooler clothing might help keep your body temperature lower, or, may help cool you down easier if you switch on cooling inside the house
Tank tops, shorts, skirts, and dresses might be some examples of clothing that keeps you cooler in the hotter months of the year.
It might also help if the clothing is made of a material and designed in a way that it allows your body to ‘breathe’, and leaves some skin exposed to cool air
2. Consider More Sustainable Home Construction Features
Some sustainable building/construction solutions might help keep a home cool compared to if a house doesn’t have them.
This might especially be true in hotter climates.
Some of these solutions might only applicable if building a new home, or, if you’re able to get renovations or modifications done to an existing house.
A few examples of that might include:
This involves proper insulation in the walls, and the roof or the loft, or even in the underfloor
Insulation can help keep the cool in, and the heat out.
Insulation with a higher R value may also have better thermal efficiency and may be better at keeping a house cool.
Different reports (from redenergy.com.au, sustainability.vic.gov.au, and thisoldhouse.com) indicate that insulation (wall insulation, attic insulation, and other types of insulation) may help save on heating and cooling bills by between 15 to 50% – depending on the house and the type of insulation installed/used.
But, home occupiers may want to consider the potential payback period on insulation first before making the decision to install it.
Some home owners say insulation is definitely worth the upfront cost for the heating and cooling benefits they receive later on, based on their experience.
– Orientating the house properly
In climates that are hotter year round, there may be options to orient the house in relation to the sun to help keep it cooler
– Using better insulating construction materials
Using better insulating construction materials for walls for example
– New modifications for an existing house
Some features or additions that might be made to existing houses to keep them cooler might be thermal shades and blinds that help keep heat out, treating external walls with a heat reflective paint that can increase heat reflection away from the house, and more.
3. Check The House For Spots Where Heat Is Getting In, & Cool Air Is Getting Out
There’s several ways that heat can enter the house, and cooler air can escape.
Doing the following things may help keep the cool in and the heat out:
– During the day, or when the sun is up, draw down or close curtains, blinds, shades and coverings for windows, doors, and glass exteriors, to minimise heat from the sun getting in
– Consider opening some windows and doors (if safe and secure to do so) at night when the sun goes down if there’s a cooler breeze that can come through the house
– Look for gaps and openings around the house where hot air could be getting through, and consider blocking them, or closing them up
These areas might occur at the bases of doors, or even at the joints of the building
As one example, a ‘door snake’ can be placed at the base of a door to keep cold air or hot air out to some extent
Be careful not to close off ventilation openings that are supposed to stay open and unimpeded though
4. Consider The Type Of Energy Your Cooling Device Or System Uses
Different types of cooling devices and systems use different types of energy for operation.
Many fans and air conditioners will use electricity, and that electricity can come from a range of different energy sources.
If the cooling device or system is getting electricity from the grid, it could be mostly fossil fuel energy, but some grids might be cleaner and rely less on fossil fuels energy sources.
A few things that might be done to change the type of energy a fan, air conditioner or cooling device or system uses might be:
– Consider changing energy suppliers to a cleaner energy supplier (where practical, and where one is available)
– Consider whether getting a home solar setup is practical and feasible
This may provide renewable energy for cooling (separate to the grid supplied energy)
Be aware of the costs, and what they potential payback period might be though before considering purchasing one of these set ups
– Consider whether geothermal heating and cooling is practical and suitable for your needs and your home
This is it’s own individual type of heating and cooling system that in the summer may draw heat from the air in the home, and transfer it into the ground (and in winter, transfers heat from the ground into your home)
Geothermal energy is considered renewable
One report from angi.com indicates that (paraphrased) some geothermal systems can lead to a 25-50% energy consumption reduction, and may be more efficient as a HVAC (heating, ventilation and air conditioning) investment
Be aware of the costs and any potential payback periods though – geothermal systems can be expensive as an initial investment, even with potential credits available (it’s worth checking if your local government or utility providers have any incentive programs to help offset the purchase price of these systems)
5. Consider How Much Energy Your Cooling Device Or System Uses
This point relates to, and is impacted several other points on this list.
But, the amount of total energy a cooling device or system uses over a specific period of time can be impacted by:
– The type of fan, air conditioner, or cooling method being used
– The brand and model of fan, air conditioner or cooling device/system (can impact how efficiently it uses energy for example)
– The settings the fan, air conditioner or cooling device/system is set to
– How long each day or night the fan, air conditioner or cooling device/system is ran for
– How insulated the space being cooled is
– The size of the space being cooled (larger spaces might require more energy)
6. Consider The Type Of Cooling Method, Or Cooling Device/System Being Used
Cooling can be categorised by the cooling method being used, and also the specific type of cooling device or system.
Both of these things are variables in the sustainability of cooling a house.
General Cooling Methods
Two of the main cooling methods might be:
– Central cooling
– Space, or room cooling
Space cooling may sometimes be more sustainable in instances where it’s only cooling one room, as opposed to a central cooling system cooling multiple rooms or an entire house at once (especially where this isn’t necessary or required)
Specific Cooling Appliances & Systems
Some of specific cooling appliances and systems that are commonly used around the house are listed below.
Note that the explanations given are generalisations – you need to confirm the potential performance or sustainability of a cooling appliance or system before you buy or use it:
– Table fans and floor fans
Come as smaller table fans, and larger pedestal or tower floor fans.
These fans consume electricity, however, some of them consume less electricity than larger AC units and AC systems.
sustainability.vic.gov.au also mentions that ‘Fans with DC motors have a lower power consumption than fans with AC motors’
The speed at which a fan is ran can also impact power consumption.
A benefit of these fans is that they are portable, and can be unplugged and used in different rooms of the house.
– Ceiling fans
A fan mounted to one ceiling in the house.
Several reports indicate that ceiling fans can use less energy than some AC units and systems.
– Floor standing AC units
Can be dedicated 2 in 1 fan and AC units, or can even be 3 in 1 units – fan, air conditioner and dehumidifier all in one.
Many manufacturers are usually transparent with how much energy or electricity the individual unit uses in the product label or description.
They also usually provide the energy star rating too.
In general, some floor standing cooling units might use a similar amount of energy as a split system or reverse cycle wall unit.
– Split system air conditioner (ductless)
Split systems come in two units (one inside, and one outside – usually on a wall in one room of the house)
Some split systems only do one of either heating or cooling, whilst some do both.
So, the difference between split systems and reverse cycle ACs is that not all split systems are reverse cycle (capable of both heating and cooling).
Split systems can be popular because they are easy to install, can be cost effective, and can use less energy than some bigger ducted systems.
– Reverse cycle air conditioner
Reverse cycle air conditioners provide both heating and cooling.
Some reports indicate that reverse cycle air conditioners are some of the most efficient and sustainable cooling units on the market.
– Evaporative air conditioner
Evaporative AC cools the air by evaporating water, compared to several other AC units and systems listed in this guide that use refrigerant gases and a chemical process to cool the air.
Several reports indicate that some evaporative air conditioners may use less electricity than refrigerated AC units – although, the cooling capacity and fan speed of the unit can make a difference to electricity consumption.
Evaporative AC also doesn’t rely on gasses.
– Central air conditioner (ducted)
Central AC (sometimes referred to as ducted air conditioning) usually uses vents and ducts to circulate and deliver air to most or all rooms of the house.
Several reports indicate that using one ductless air conditioning unit uses, on average, less energy than a ducted central AC system.
Floor fans and ceiling fan may also generally use less energy than large central cooling or ducted cooling systems.
However, using multiple ductless units or fans across a house will increase energy consumption.
Other Cooling Systems
– Air source heat pumps
Air source heat pumps are capable of both heating and cooling.
A range of reports indicate that they are both cost effective and energy efficient.
– Geothermal heating and cooling systems
We mentioned and explained geothermal heating and cooling systems above in this guide
They might be considered a renewable heating/cooling system, and may help save on energy consumption and increase efficiency in some ways
In comparison to air source heat pumps, geothermal systems might draw heat and transfer heat to and from the ground (instead of the air), and may use less electricity in some instances (according to some reports)
– New or recently developed cooling devices, systems or technology
There may be other cooling devices, systems or technology that get developed in the future that offer other sustainability benefits not mentioned here in this guide
7. Consider The Individual Brand & Model Of Cooling Device Or System
The individual brand and model of the cooling system or device can impact sustainability in various ways.
The individual design and features of the different brands and models obviously matters.
But, one of the key features that may play a role, apart from it’s cooling capacity, might be it’s energy efficiency.
Cooling devices and systems that have better energy efficiency might be the ones that have a higher energy efficiency star rating e.g. it might rate 4 or 5 stars, out of a total 5
The cooling device or system may also come with information about how much electricity they use per minute or hour they are in operation.
Apart from looking for the energy efficiency rating of a cooling appliance or system, a consumer may look for other energy saving or energy efficient technology and features, including but not limited to:
– The cooling technology the product uses
sustainability.vic.gov.au mentions that inverter technology may be more efficient than compressor technology:
‘Inverter air conditioners are generally quieter and more efficient than air conditioners that use the older compressor technology’
– Whether it uses smart technology
For example, some cooling appliances or systems might work with smart technology, which can help save energy via automation of some functions.
8. Consider The Sustainability Of Your Cooling Practices
Some cooling practices that might help save energy might be:
– Considering the number of cooling devices you’re using in the house at any one time
Are you using one, or multiple cooling units?
More cooling units in operation generally means more energy being used.
– Only cooling the room you’re using
This is instead of cooling multiple rooms or the whole house that aren’t being occupied or used
– Only using cooling devices and systems whilst you’re at home
i.e. make sure to turn cooling off when you leave home – especially when leaving for work
– Getting your cooling systems serviced periodically as required
9. Consider Sustainable Cooling Settings & Features
Some settings that might help save energy might be:
– Using a timer or auto shut-off feature
This is so the cooling device or system shuts off when you’re not there to turn it off manually
– Considering how the temperature the AC unit or system is set to impacts sustainability
The less an AC unit has to cool the air (i.e. the closer it is to room temperature), the less energy is might use on cooling in some instances
– Consider the speed of any fans
The higher the fan speed, the more energy it might use
The Potential Impact Of Cooling On Sustainability Around The House
Space heating and cooling can be the main activities that use the most electricity/energy around the house
There may be a carbon footprint and other environmental impacts that stem from this, particularly related to energy use
Some of the general sustainability factors to consider with different cooling methods might be:
Whether a cooling device or system uses energy excessively or inefficiently
Whether a cooling device or system uses energy sources or fuel sources that aren’t renewable – coal, oil, natural gas (all fossil fuels), compared to using more renewable energy sources
What the carbon footprint of a cooling device or system is – the energy source can play a role here too
Whether a cooling unit uses refrigeration gases and chemicals
What’s The Most Sustainable Or Eco Friendly Way To Cool A House?
Using methods that use no energy, or less energy, fuel and power/electricity might be the most eco friendly or sustainable.
But, they may not always be practical.
Of the powered cooling methods and options, fans, portable floor AC units, split systems, and reverse cycle systems can all be convenient, efficient, and sustainable in different ways for the cooling they provide.
Evaporative units may have the sustainability benefit of not using refrigeration gases.
Heat pumps can be cost effective, efficient and sustainable.
Geothermal systems can be sustainable and might be considered renewable with the way they operate (aside from a small amount of electricity they might use for their pump), but geothermal systems can be much more expensive to purchase/install that the options listed above.
Obviously, there’s variables to answering this question.
The individual cooling device or system brand and model matters – the total energy use and energy efficiency of the product/system matters i.e. how efficiently it converts energy to cooling, and how much energy it uses per unit of cool air it delivers
How the user uses the cooling device or system also matters.
List Of Factors That Can Impact The Sustainability Of Cooling A House
Ultimately, there may be no one ‘most sustainable way to cool a house’, or ‘most sustainable fan or air conditioner’.
There may instead be multiple things that can make cooling ‘more sustainable’ when used in combination with each other, such as:
– Wearing clothes that keep you cool
– Having a house that is reasonably well insulated or kept passively cool (heat kept out, cool air kept in)
– Using less energy, fuel and electricity where possible is generally more sustainable (i.e. using less power, but also using passive cooling methods where possible, and preventing the need to use active cooling and powered cooling as often)
– Using a reasonably energy efficient cooling unit or system
– Using a cleaner or more renewable energy for cooling units and systems
– Using cooling units and systems in a responsible way (and not wasting energy cooling excessively or unnecessarily)
– Making use of sustainable settings
– And so on
Potential Tradeoffs To Different Cooling Methods & Systems
It’s worth mentioning that sustainability doesn’t guarantee affordability, and not all types of heating suit all geographic locations and houses.
Homeowners should consider things like:
– The initial purchase cost of the cooling device or system, and how long until a setup pays itself off
Looking for grants, credits and concessions may sometimes help
– Operating cost
The costs can be different to run different types of cooling devices and systems
A basic pedestal fan may use less electricity than a large ducted central cooling system for example
– The space a cooling device or system needs
Some geothermal systems may need more room than a simple floor fan, just as one example
– The installation a cooling unit or system needs
A floor fan requires no installation (only plugging in), whilst split systems and reverse cycle systems might need to be installed into a wall, just as a few examples
– The climate conditions required
Some solar setups need certain climates or conditions with enough sunlight for example
– Plus other factors
Sustainable Ways To Heat A House
The guide above is complementary to a separate guide we put together on potential ways to sustainably heat a house.
1. Various ‘Better Meets Reality’ guides