Does Insulation Help with Heat? Save Money on Your Power Bill This Summer

home insulation

Australia’s predominantly hot climate can make summers unbearable, while the “cooler months” can offer little rest in humid and subtropical zones. With both energy costs and average temperatures increasing, many rural and metro areas across Australia are suffering from a perfect storm of a changing energy market and a warming climate.

It’s therefore no surprise that many are turning to insulation to help regulate heat. 

Today we will look at the science behind insulation and heat transfer to demonstrate how insulation can help maintain comfortable indoor temperatures all year-round.

The science of heat transfer and insulation 

The secret to regulating your temperatures inside the home lies in the science of insulation and heat transfer. Knowing how insulation interacts with the three types of heat transfer – conduction, convection, and radiation – allows you to create a cool indoor sanctuary. With proper installation and consideration of factors such as the R-value, insulation can not only help keep you comfortable, but also save you money on energy costs. 


Conduction refers to the transfer of heat through a material or between two materials that are in close contact. For example, heat can be conducted through materials such as walls, floors and roofs. Insulation works to reduce conductive heat transfer by slowing down the movement of heat through the material. For example, fibreglass insulation works to reduce conductive heat transfer by trapping air in small pockets between the fibres, which slows down the transfer of heat.


Convection refers to the transfer of heat through a fluid (such as air or water) due to differences in temperature or density. In a typical building, heat can be transferred through convection when warm air rises and cool air sinks. This is why attics and roofs can become particularly hot during the summer, as the hot air rises and creates a convection current. Insulation works to reduce convection heat transfer by providing a barrier between the two environments.


Radiation refers to heat transfer via electromagnetic waves. Heat energy is emitted by a source of warmth and absorbed by a cooler object, regardless of whether or not they are in contact. An obvious example is the sun radiating heat onto the roof of a home. This is why reflective insulation is often used in attics and walls, as it reflects radiant heat away from the home.

Does insulation help with heat?

In short, Yes. But to fully comprehend how insulation works, it’s useful to understand how these three processes interact to generate heat transfers in your home. Heat naturally moves from high thermal energy areas (hot areas) to low thermal energy areas (cool areas), until an equilibrium temperature is reached. Insulation acts as a barrier and slows down this process, maintaining a cooler indoor temperature for a longer period.

Bulk insulation, such as insulation batts or rolls, functions by capturing billions of tiny air pockets within their structure. These pockets break up the path of heat transfer, impeding it and preserving a cooler home in summer and a warmer one in winter. It’s critical that bulk insulation is not compressed during installation since it will diminish its effectiveness.

Reflective insulation, on the other hand, reflects radiant heat from the sun away from your home. Typically installed in the roof, it features a thin foil layer that needs to be kept clean for effective reflection of radiant heat.

How can I improve the insulation in my home or business?

Many buildings in Australia are under-insulated, meaning a significant proportion of Australian families are not reaping the benefits home insulation offers. This is true particularly for older homes that may have been insulated decades ago. Other factors such as extreme weather, water damage or rodent infestation can also reduce the life of insulation. In these cases, damaged insulation should be replaced.

For effective home insulation, first ensure that your ceiling, roof and external walls are well insulated. The roof is responsible for up to 35% of your home’s heat loss and gain, while the walls are responsible for as much as 25%. It is important that you choose home insulation products with the right R-Value. 

Check out the table below for our recommended R-Values for ceilings and walls in Australian homes.

Where Ceiling/Roof External Walls
Perth, Brisbane, Northern NSW R4.0 R2.0
Melbourne, Sydney, Adelaide R5.0 or R6.0 R2.5

Insulation in the floors, internal walls and in between floors of a double-storey home can also make a significant impact on heat regulation. When these are insulated, you can achieve more energy-efficient heating and cooling. For added noise-reducing benefits, you may want to invest in specialised acoustic insulation.

What insulation should I choose?

With so many products on the market, it’s difficult to know what type of insulation is best for your needs. Here are some general types of insulation to consider using when regulating your building’s energy efficiency for hot temperatures.

Reflective foil insulation

This insulation comprises a thin foil layer on one side that reflects radiant heat from the sun away from the building. This makes it ideal for roofing and should be installed with a pocket of air below the reflective side in order to work effectively. Reflective foil insulation is useful in hot climates and can also help prevent moisture build-up.

Insulation rolls and batts

This type of insulation works by trapping billions of tiny air pockets to ensure that the heat transfer is slowed down to protect interiors from heat gain during the summer months and heat loss during the cooler months. Insulation rolls and batts like Earthwool, Pink Batts, Bradford Gold, Bradford Polymax and GreenStuf can be fitted on floors, ceilings, and walls. 

PIR insulation

PIR insulation is a type of thermal insulation that’s widely used in the construction industry due to its excellent fire performance and high resistance to heat transfer. Its structure comprises rigid foam panels that contribute to its superior thermal properties. A great example of PIR insulation is Primax, which can be used for ceilings, walls, roofs and underfloors.

Tips for selecting the best insulation solutions for hot climates

Insulating your home or business in hot climates presents unique challenges compared to other climate zones across Australia. Here are a few tips when insulating a home in extremely hot weather.

Opt for a high R-value

The R-value measures the insulation’s resistance to heat flow. The higher the R-value, the better the insulation’s thermal performance. In hot climates, look for insulation with a high R-value to prevent heat from entering your home.

Reflective is key

Reflective insulation is designed for sunnier and hotter climates and can effectively reduce the amount of radiant heat entering your home. Look for insulation with a foil surface that can reflect heat away from your home.

Prioritise ventilation

Proper ventilation can help remove hot air and moisture from your home, preventing it from becoming too hot. Consider insulation options that provide ventilation, such as batt insulation with ventilation channels or spray foam insulation that allows for airflow.

Location is everything 

Different areas of your home require different types of insulation. For example, the roof space needs insulation with a higher R-value than walls or floors. Consider the location of the insulation before choosing a solution to ensure maximum efficiency and performance in hot climates.

Long-term benefits of investing in quality insulation

When living in a hot climate, it’s easy to ignore the long-term benefits of installing insulation. But with higher energy prices, this is changing. 

As the cost of cooling homes rises, insulation is increasingly becoming a more affordable and sought-after solution. Often the up-front cost of installing insulation will be greater than a year’s combined energy bill. However, after a few years, most customers see a positive return on investment that will only grow over time.

Protect your building against hot temperatures with premium insulation

With average temperatures on the rise, equipping your home or business with insulation is essential. At Pricewise, our wide range of premium and trusted Australian insulation solutions are only one click away. Shop on our online store or contact our expert team for more details on what insulation type is right for you.

Thermal insulationBrowse All

3 thoughts on “Does Insulation Help with Heat? Save Money on Your Power Bill This Summer

  1. Shane Bond says:

    I have kauri pine floor old home over 100 years on stump in kitchen area 4 feet above the ground I can feel cold coming up thinking of the foam -what can you suggest

    • Pricewise Insulation says:

      Hi Shane,

      Thanks for your question. It really depends on where you live in Australia. We typically recommend R2.5 Polyester Underfloor Insulation or R2.5HD Earthwool FloorShield Insulation Batts. Polyester insulation is best in areas that are prone to moisture, as it does not absorb water.

      If you would prefer a foam product, then we would recommend Expol Insulation. However, this product has a lower R-value than the other products we’ve suggested.

      Feel free to give our team a call on 1300 729 639 if you have any questions.

      Kind regards,

  2. Olsen J. says:

    One additional tip I would suggest is to prioritize proper ventilation alongside insulation in hot climates. Ventilation helps remove hot air and moisture, enhancing the overall cooling efficiency of the insulation. Additionally, considering the location-specific insulation needs within a building can further optimize its effectiveness in regulating heat.

Leave a Reply

Your email address will not be published. Required fields are marked *

Reach out for a quote today