Cool Heads, Warm Homes: Cracking the Heating and Cooling Code

[Sarah] (0:00 - 0:09)
So basically, if you have a gas heater in your home and you have a reverse cycle air conditioner on your wall, it's much, much cheaper to use that air conditioner than it is to use that gas heater.

[Jimmy] (0:10 - 0:10)
Unequivocally, yes.

[Sarah] (0:16 - 1:06)
Welcome to the Good Energy Guide. No jargon, no guesswork, just better energy choices. Brought to you by Ausgrid, electricity distributor for Sydney, the Central Coast and Hunter region.

Hello, I'm your host, Sarah Aubrey. Today, we're talking about a part of the home that quietly drives up energy bills more than almost anything else, heating and cooling. We'll explore why reverse cycle systems are now one of the most efficient ways to stay comfortable, what they really cost to run compared to gas, and which settings actually save you money.

To help us break it down, we're joined by Jimmy Lee, co-founder and technical director at ZapCat. Jimmy specialises in making clean energy choices simple, and he's here to help us understand what actually works in the real world. Welcome, Jimmy.

[Jimmy] (1:07 - 1:08)
Thanks, Sarah. Great to be here.

[Sarah] (1:09 - 1:13)
Heating and cooling use a big chunk of household energy. Why do people underestimate that?

[Jimmy] (1:14 - 1:51)
That is a really great question. And when we say a great chunk, we're talking about maybe 40%. That's so much.

It really is. It's the single largest source of energy usage in the home, inside the home. And it's a big reason for that is it just generally takes a lot of energy to heat things.

And you know, you're heating your whole home, there's a huge volume of air. And if your home is not well insulated, for example, there's a huge amount of heat loss between your home and the outside environment. So, you just have this appliance that's constantly, it's just always hungry for more power to kind of keep it at the temperature you want.

[Sarah] (1:52 - 1:57)
And if you have a leaky home with not very much insulation, it's working harder and harder and harder to heat that space. 

[Jimmy] (1:57 - 1:57)
That's right. Yeah.

[Sarah] (1:58 - 2:03)
So reverse cycle systems are now seen as one of the most efficient ways to heat and cool a home. What's changed?

[Jimmy] (2:04 - 2:32)
I think in the past, air conditioning was associated with just cooling, because it's the same principle as a fridge, right? You're taking heat from one place and you're moving it somewhere else. So, you can take heat from inside your fridge and move it outside, or you can take heat from inside your home and you can push it outside your home.

And so over time, as a technology evolved, air conditioning units became reverse cycle in that they could both heat and cool, they can move to temperature both ways.

[Sarah] (2:33 - 2:41)
And that technology must have improved and improved. So, an air conditioner from 20 years ago would be quite inefficient compared to an air conditioner made today, correct?

[Jimmy] (2:41 - 2:55)
Yeah, absolutely. So, if you look at the energy stars on your air conditioner or compare it to older air conditioners, you can see that in the past you get one or two stars and they're very standard. And it's very common to see six or seven star air conditioners now.

And that is just a function of technology improving.

[Sarah] (2:55 - 3:16)
Actually, if you're looking for a new air conditioner, because I even did a spreadsheet because I like that, you need to look for the EER and the COP rating. Is that correct? 

[Jimmy]
You can.

[Sarah]
The EER is the cooling and the COP is the heating rating, but that's the star rating. So, the higher that rating is, the more efficient that air conditioner is, and therefore the cheaper it is to run.

[Jimmy] (3:16 - 3:54)
That's right. So, I'll explain what they are really simply. EER and COP are just ratios explaining for every unit of power you put into the air conditioner, how much heating or cooling do you get?

So, for every one kilowatt of power you supply to the air conditioning unit, it actually gives you five kilowatts of heating. So, it's like a five for one discount. 

[Sarah]
That's huge.

[Jimmy]
It is, it is. And the reason that's possible is because you're not directly using that one kilowatt to heat, you're using that one kilowatt to move heat. So, you take advantage of all the ambient heat that's already around in the atmosphere.

[Sarah] (3:55 - 4:27)
And that's different to say a space heater on those little heaters that you'd be heating a bedroom with or probably a rental. They're a one for one for every one kilowatt you put in, you get one kilowatt back. Is that right?

[Jimmy]
That's right. Because you're just... 

[Sarah]
They're 100% efficient, but that's not actually that great.

[Jimmy]
Exactly. A hundred sounds good, but no, we want 500. 

[Sarah]
It is 500% efficient with an air conditioner. That is absolutely extraordinary. So that's why they're so cheap to run or efficient. 

[Jimmy]
That's right.

[Sarah]
I think a lot of people think a gas heater is cheaper to run than an air conditioner. Is that true?

[Jimmy] (4:27 - 4:28)
No.

[Sarah] (4:30 - 4:32)
Please take note. It's not true.

[Jimmy] (4:32 - 4:38)
So, there are historical reasons for this. Because in the past, gas was a lot cheaper.

[Sarah] (4:38 - 4:39)
Yes.

[Jimmy] (4:39 - 5:18)
It was a lot cheaper for a number of reasons. We were exporting less gas, for example. And we had access to easier to extract sources of gas.

So, gas prices have definitely gone up steadily over the course of time. And what cheap gas prices masked was the fact that gas heating is not very efficient. It wasn't very efficient, but it was cheap.

So, you don't notice that it was expensive. 

[Sarah]
Kind of like petrol. 

[Jimmy]
Just like petrol. Exactly, exactly. And now that gas prices have gone up and the unusual era of cheap gas is over, you have a much more like-for-like comparison with how much does an appliance actually cost to run. So now you notice that gas costs a lot more.

[Sarah] (5:18 - 5:27)
So basically, if you have a gas heater in your home and you have a reverse cycle air conditioner on your wall, it's much, much cheaper to use that air conditioner than it is to use that gas heater.

[Jimmy] (5:28 - 5:28)
Unequivocally, yes.

[Sarah] (5:29 - 5:33)
What do people commonly misunderstand about heating and cooling and how it actually works?

[Jimmy] (5:34 - 6:37)
I think people often don't think of how to zone their homes. And what I mean by that is if you're heating, are you heating just a room or are you actually trying to heat your entire home? So, if you're just in the living room all day and you're just heating that room, it'll be way more efficient than if all your doors are open and all your hallways are open.

Whatever you have heating in that one room is leaking out to the rest of your home. So, the volume of space you're trying to heat and cool is a huge factor in how much expensive it's going to be. Now, by extension, if your home is really leaky, if it's poorly insulated, you have lots of drafts, you have gaps and cracks, doors and windows, thin windows.

And if you have a heater on anywhere in your home, you're not just trying to heat your home, you're kind of trying to heat the whole world because there's not much barrier between your home and the rest of the world. So, you have so much heat just escaping. And so, the more you can control where the heat stays, the less it'll cost.

[Sarah] (6:38 - 7:11)
I think people don't realise, I mean, you might electrify your house and put in all these energy efficient air conditioners. I'm not sure that people realise you also have to insulate. You also have to put good wall coverings over your windows, which are a hole in your thermal envelope because it's essentially a hole in your wall.

And those things work in conjunction because if you've got good insulation and the house isn't leaky, you close up all those gaps and cracks and then you turn on an efficient air conditioner. It doesn't have to work so hard and it just retains the heat. That's how you really bring down those bills, isn't it?

[Jimmy] (7:12 - 7:48)
That's right. They're two sides of the same coin. So, when we think about how energy efficient a home is, we often think about how much heat is required to keep this home in a comfortable temperature.

And the better insulated your home is, the better your thermal envelope, the lower that figure, right? And the lower the figure, you know, the cheaper it'll be. So that's one side of the equation.

And on the other side of the equation is, what is the most cost-effective way to get that amount of energy? You know, you could get it through a recycled air conditioner or you could spend more and get it through gas.

[Sarah] (7:49 - 8:11)
So, if I was going to renovate my house or make it more efficient, is it better to put in ducted air and heat the whole home or is it better to zone that? Or is it better to put in individual wall splits or units in each room? So, my understanding is that it's better to put those individual units in.

Is that correct? Is it more efficient to have individual units in each room?

[Jimmy] (8:12 - 8:31)
Well, efficiency is one consideration, but there are other considerations too that you need to balance. For example, if you have a split system, if you have multiple split systems, one thing that you have is redundancy. So, if one breaks or stops working, the rest of them still work.

[Sarah] (8:31 - 8:32)
Yeah.

[Jimmy] (8:32 - 9:09)
So that's one advantage. But then on the other side, if you have five individual split systems, each of those needs to have its own external, um, compressor on the outside. So, you take up a lot of space and a lot of noise.

It can get really ugly and, you know, really noisy and inefficient. So how do you kind of balance these sort of trade-offs? Um, one way of balancing it is you might have a multi-split system where you have a single outdoor unit that's connected to multiple indoor units.

So, you know, you might have three, uh, they call them heads. So, three indoor units that...

[Sarah] (9:10 - 9:11)
The bit that goes on the wall.

[Jimmy] (9:11 - 9:15)
The bit that goes on the wall that gives you your cold and hot air, but they're connected to the same unit on the outside.

[Sarah] (9:15 - 9:17)
So, you only have one unit outside.

[Jimmy] (9:17 - 10:02)
Exactly. So, but then that's an example of trade-off because, okay, you have three times less units outside, but now you have three units depending on the same thing. Right.

Right. And so, ducted is just a more extreme version of that. You have one unit outside for everything in your home.

And so, I think as in the real world, it often comes down to practicalities, which is do you have space for all these multiple units outside? How important is having redundancy for you? There's often a point at which adding more split systems just becomes less cost effective than just putting in a multi-split or putting in a ducted system.

Right. So, you want to not go into it blindly saying one is better than the other, but just evaluate what would happen if I did this? What would happen if I did this?

And what actually makes most sense for me?

[Sarah] (10:02 - 10:25)
So, you should speak to your installer and say, I would actually say, what are the running costs going to be for this? Because often you'll get an installer come around and go, oh, you should just put inducted or because they just look around and go that would work best here. But I don't think we often ask tradies enough, which is going to be cheaper to run?

What's going to give me the best bang for my buck in terms of ongoing running costs?

[Jimmy] (10:25 - 11:40)
I would say tradies who do air conditioning installations often don't know or really think about the efficiency side too much. One reason is that air conditioning is a product that actually can be quite tricky to install sometimes. You need to drill through brick walls.

You have physical space considerations. And what they're really good at is figuring out how to make something work. So, I feel like it's the homeowner who needs to drive that conversation more.

So, I really want this or I really want this. How can you make it work? Because if you ask them for a recommendation, it's often that they'll figure out what's most easy to install, which is not a terrible thing because you want something that's easier to install is cheaper.

And often your options are limited by your physical constraints. Most apartments, if you live in an apartment that doesn't have ducted, you probably can't put in ducted. It's just not going to do it.

Whereas if you have a freestanding house, you might have more options. So, what I would say is just ask your installer for, say, a ducted option versus a split option and see what the costs come back. That already might just be a deal breaker for you because it could be thousands of dollars difference between the two.

But in terms of efficiency, I would say that ducted is generally slightly less efficient than split systems.

[Sarah] (11:40 - 11:45)
Okay. So in simple terms, how does a reverse cycle system produce heating and cooling so efficiently?

[Jimmy] (11:46 - 12:26)
Well, a reverse cycle air conditioner is a form of a heat pump and all heat pumps, like your fridge, all of them, what they do is they just move heat from one place to another. And so, because they are moving heat around, they're not creating heat. They're making the most of what's already there.

That's why it's more efficient because you're borrowing what's already there and you're directing it to the right place. And that's where the... 

[Sarah]
You're not producing something.

[Jimmy]
You're not producing something. And that's when we say you're inputting one kilowatt of power, that one kilowatt is just being used to move things. It's not being used to produce something.


[Sarah] (12:27 - 12:30)
Right. How do running costs compare between reverse cycle and gas heating?

[Jimmy] (12:31 - 13:13)
I would say that gas is maybe three to four times more expensive on a per square meter basis. 

[Sarah]
Really? 

[Jimmy]
Yeah.

[Sarah]
That is heaps. 

[Jimmy]
It's heaps. And actually having a resistive heater is actually probably four to five times more expensive.

So even more expensive. 

[Sarah]
Wow. 

[Jimmy]
So that is partially a contributor to why people think gas is cheaper because, yeah, your gas heater might be slightly cheaper than your electric resistive heater.

But that doesn't mean gas is more efficient or better. It just means that the unit cost of gas is slightly less, which is why it seems a little bit cheaper. But the most efficient method by far is reverse cycle air conditioning.

[Sarah] (13:13 - 13:17)
Yeah. Why do gas systems tend to cost more to run now?

[Jimmy] (13:18 - 13:33)
It's because the cost of gas has gone up. That's the short answer. And because gas was, I would say, unusually cheap before, it masked a lot of the inefficiencies of old gas heaters.

So, it was always expensive. You just never noticed it because gas was cheaper than it should have been.

[Sarah] (13:34 - 13:37)
Just to clarify, what is an electric resistive heater?

[Jimmy] (13:38 - 14:05)
When we use the word resistive, we mean that there is a heating element somewhere. So, if you imagine your kettle, that's resistive because there's a heating element that's heating your water. So most electric heaters that aren't hot water heat pumps, they have some sort of heating element that's just producing heat through raw energy.

You know, you're just turning electricity into heat. 

[Sarah]
And they're expensive. 

[Jimmy]
And it's expensive too.

[Sarah]
Or inefficient. 

[Jimmy]
It's inefficient to do it that way.

[Sarah] (14:06 - 14:08)
What drives big bill spikes in winter and summer?

[Jimmy] (14:09 - 15:13)
Well, firstly, most people don't really think about energy in their home that too much. But when they do, they think of it in terms of when they use things. And often they're not thinking about how is everyone else using things.

And so, if you imagine a really hot summer's day, and in the middle of the day, everyone's blasting air conditioning, right? And to a large extent, you don't notice that. The electricity grid doesn't notice that because there's so much solar kind of counteracting that.

But let's say it hits 6pm, 7pm, and it's still super hot. But while the solar stopped generating, but everyone's got their air cons on, suddenly, you have really high demand for electricity on the grid. And that causes a lot of problems for the electricity network, which most people don't really think about.

And the network has to compensate for that somehow, right? So often you might have a type of tariff on your energy bill from a retailer. That's your retailer attempting to reflect the true cost of electricity based on the time that you're using it.

[Sarah] (15:14 - 15:25)
Trying to encourage you to not use as much electricity at that particular time. 

[Jimmy]
That's right. 

[Sarah]
Interesting. What everyday mistakes do people make that push heating and cooling costs up without them noticing?

[Jimmy] (15:26 - 15:54)
We could think of it in terms of zoning again. And maybe a visual way of approaching it is, let's say you're in your bedroom, you've heated your bedroom through whatever form of heater you have. What you've done is you've converted money to heat.

So, floating all around you is basically money. And if you open your window, your heat leaves, but your money is going out the window. 

[Sarah]
Bye.

[Jimmy] (15:54 - 16:40)
Goodbye.

So, if you think about it in those terms, your annoying dad telling you to save energy makes a bit more sense. But also, it helps you visualize how to make your home more efficient and spend less money because you can just imagine where this heat is going. So, a couple of mistakes that people often make is just letting that money float out the door.

So, for example, you might heat your bedroom, but leave the door open. Bye. It's going away.

You might have gaps or cracks under your, you might have a big gap under your front door, or you might leave your window open, or you might have gaps in your windows. 

[Sarah]
Or not close your curtains. 

[Jimmy]
Not close your curtains.

That's your money just going out the window.

[Sarah] (16:40 - 16:41)
Drifting through the glass.

[Jimmy] (16:42 - 16:55)
Exactly. And so, everything you can do to save bills on heating and cooling revolves around how do you kind of keep that heat or keep that money inside your home or keep it where you need it.

[Sarah] (16:56 - 17:08)
Okay, so that's the big picture. Let's get into the practical stuff people can do right now to save money. I think closing curtains is a big one.

What do you think?

[Jimmy] (17:08 - 17:27)
I agree. So, there are a few behavioral things that are completely free that you can do. You can close curtains in winter to keep the heat in.

Totally true. But on the flip side, you can also close curtains on western facing windows in summer to block heat from coming in. So, it works both ways.

[Sarah] (17:28 - 17:31)
Or outdoor. A shade outside the window so it doesn't hit the glass.

[Jimmy] (17:31 - 18:09)
That's right. Putting an awning or something outdoor, or some pot plants or something that creates some shade, that helps a lot as well. Another thing is if you have a recycled air conditioner, you can mess with the thermostat settings.

For example, in winter, you don't want to crank the heat up to 30 degrees, even though it feels really nice and toasty. It gets exponentially harder because the temperature difference between your home and the outside is just so great. So, it gets much harder to convince your money slash heat to stay inside your home.

So, in winter, you could heat your home to, say, 20 degrees. In summer, you could cool your home to, say, 25 degrees.

[Sarah] (18:10 - 18:13)
So that one degree even changing it on your thermostat can make a big difference.

[Jimmy] (18:13 - 18:23)
It will make a difference. A number that's commonly thrown around is every one-degree change in a thermostat is about 10% difference in the running cost. 

[Sarah] (18:23 - 18:53)
Wow. A biggie I learned about was dry mode. That's a big one for me. So, in summer, as it becomes more humid, particularly in Sydney and surrounds, we're not quite so used to the humidity.

I've noticed with dry mode, it actually uses about a third of the electricity of having it on cooling. I've had lots of reports of people following that advice. I had one guy who said his partner was working from home all day and just in one month, they saved $60 on their energy bill just from switching to dry mode.

[Jimmy] (18:53 - 18:55)
I actually did not know that. That's interesting.

[Sarah] (18:55 - 19:30)
Yeah, and it's not as full on as cooling. So even if it's a really hot day, I've noticed you can cool, put it on cooling and then switch to dry mode if you feel like dry mode isn't quite cutting it or get the air conditioner on a bit earlier in the day and keep it on dry mode. We've noticed as well with our air conditioner that it's good to, when you say 20 degrees in winter, we tried that and we just couldn't get the room warm.

But what we initially then did was sort of blast the room for about 20 minutes, get that temperature up and then reduce it down to 20 degrees. That was the way we sort of learnt to heat the space better.

[Jimmy] (19:30 - 19:48)
Absolutely. There's a term out there called pre-conditioning as well. Pre-conditioning using your air conditioner.

And this especially applies if you have something like solar where you have very affordable electricity or free electricity during the day. You just blast it when you have energy to spare, right? Cool your home down.

[Sarah] (19:48 - 19:49)
Get it to the temperature you want.

[Jimmy] (19:49 - 20:00)
Exactly. Because much of the energy use will be in that initial blast where you're trying to change the overall temperature of the room and your air con won't be running at full blast afterwards.

[Sarah] (20:00 - 20:08)
Yeah. What about turning things on and off all the time with your air con? Is it better to leave it on or turn it off, turn it back on?

[Jimmy] (20:09 - 20:46)
I think some people like to mess with things and I would say, I'll give a really practical answer which is I don't do it for my air conditioning because I'm more worried about the wear and tear of turning it on and off constantly than I am about maybe small efficiency gains. So, if I try to turn it on and off, I'll do it more in larger chunks. For example, you know, blast it during the middle of the day and then leave it off for a few hours during the peak.

And I think many people also don't really have time to constantly fiddle with the controls as well. So, it's not something that would be my first line of defense.

[Sarah] (20:47 - 20:54)
Yeah. So, what temperature settings work best for comfort and affordability in winter and summer? What should I set it to in winter?

[Jimmy] (20:54 - 21:44)
I think 20 in winter and 25 in summer is a reasonable balance. It's art more than a science because it's not that you set to 26 and then suddenly everything drops off a cliff, right? It's all kind of goes along a scale and many people find that 25 is tolerable in summer and 20 is tolerable in winter.

So that's a good starting point to try. And you find that it's not powerful enough for you, then fiddle with it. At the end of the day, we want our homes to be comfortable.

So, you don't want to be too extreme with all your energy efficiency measures to the point where your life is miserable. So, you know, this 20, heating the 20 and cooling the 25 is a rule of thumb. It's a guidance, right?

And it's guidance as to what temperature is you might be okay with. And so, if you want to get there faster, absolutely.

[Sarah] (21:45 - 21:48)
Is it better to keep a system at a steady temperature or switch it on and off?

[Jimmy] (21:50 - 22:07)
I think that you would want to make bigger changes when the electricity is cheaper. So, if you have solar, you'd want to make the most of solar during the middle of day when it's blasting. And then you might leave it off during the evening peak when electricity is really expensive.

[Sarah] (22:08 - 22:11)
And if you've got a house that's well insulated and not leaky.

[Jimmy] (22:11 - 22:11)
Exactly.

[Sarah] (22:12 - 22:21)
My old air con, we used to have ducted air and it was 15 years old and you'd turn it off and the house would be freezing again after 20 minutes. So that wouldn't work so well in that situation.

[Jimmy] (22:21 - 22:30)
Exactly. If your home is quite leaky, then you're probably just leaving it on constantly because you need to replace that volume of heat that you're losing all the time.

[Sarah] (22:30 - 22:41)
Yeah. So, what small adjustments can have the biggest payoff? I think curtains, curtains and blinds, closing those window coverings, your hole in your thermal envelope.

What else?

[Jimmy] (22:41 - 23:07)
Well, I'll talk about some small adjustments and I'll mention some big ones too. So, for small adjustments, curtains, yes. And the way curtains work is you want to insulate your home from the outside world.

And the way you do that is you want a layer of still air between your curtain and your window. So, it works best when your curtains aren't too thin, when your curtains perhaps have a palmette. So that's another thing.

[Sarah] (23:07 - 23:07)
Yeah.

[Jimmy] (23:09 - 23:25)
Draft roofing. So, most people have gaps under their front doors, external doors. They might have small gaps in their windows.

They might have gaps in their floorboards or in their ceiling. 

[Sarah]
And skirting boards. 

[Jimmy]
Skirting boards.

[Sarah] (23:26 - 23:26)
Get out the caulking gun. Yeah.

[Jimmy] (23:27 - 23:35)
So going back to the energy is money analogy, you're holding all this money hostage in your home. They're trying to escape. So, you're going to block off all the escape paths.

[Sarah] (23:35 - 23:35)
Yeah.

[Jimmy] (23:35 - 23:57)
So, then you don't need to use more energy to create more heat. In terms of the small changes, it's draft proofing and curtains are honestly the main ones. But the most impactful thing most people experience is putting in ceiling insulation.

That's where you tend to lose most energy in your home. And it's often the most practically feasible place to do it as well.

[Sarah] (23:58 - 24:23)
I've actually got a good one for renters for saving money. The heated throw. The heated throw is so amazing.

You heat yourself rather than the room. And they're really cheap to run, but they're really cozy and really fantastic. So, it's a really, not just for renters even, it's just a lovely, cheap, affordable way of keeping warm.

If you know that you're sitting in front of the TV, you're not going to be moving. You're going to be sitting there for a few hours. It's just a great way to stay warm.

[Jimmy] (24:23 - 24:25)
Absolutely. Yeah. You're heating yourself, not the room.

[Sarah] (24:25 - 24:31)
Yeah. For households on gas heating, what should they think about before switching to reverse cycle?

[Jimmy] (24:32 - 24:49)
Depends on what type of gas heating you have. So, if you have a gas ducted system, for example, which is pretty common in some parts of the country, like Victoria, the ducts you have might not be of the right size for an equivalent ducted air conditioning unit. So, there are practical considerations there.

[Sarah] (24:49 - 24:55)
And that's the most expensive way to heat your home, isn't it? That gas, the ducted gas.

[Jimmy] (24:55 - 25:10)
Ducted gas, yes. It's very expensive. 

[Sarah]
Yeah, it's a real shame.

[Jimmy]
I wouldn't say, it depends on the climate as well, but I would say, if you have a whole bunch of electric panel heaters all around your home as well, and that's what you're doing, that's pretty bad too. 

[Sarah] (25:12 - 25:19)
That is pretty bad. And unfortunately, that's the only thing that some renters have, isn't it? Because I've lived in lots of rentals where there was absolutely no heating or cooling in the property.

[Jimmy] (25:19 - 25:19)
Exactly.

[Sarah] (25:20 - 25:30)
So, if someone was replacing their gas heating, which can be very cozy, is air conditioning as comfortable? Would you be just as cozy in your home?

[Jimmy] (25:30 - 26:05)
I think one characteristic gas systems can have is sometimes they're really large, they're really powerful, they're really oversized. And so, blasting your gas heater on a really cold day in a cold part of the country, it can mask a lot of other problems in your home. So, if your home is really leaky, you might not notice it because the gas is just compensating for it.

And so, we do have some homeowners talk about how when they switch from gas to reverse cycle air conditioning, that it feels weaker or it's less comfortable. But that's not really... but I feel like the root cause there is not that there's anything wrong with the air conditioning.

[Sarah] (26:05 - 26:06)
It's the leakiness of the house.

[Jimmy] (26:06 - 26:07)
The leakiness of the house.

[Sarah] (26:07 - 27:06)
And the lack of insulation. All right. Well, thanks very much.

Thank you. So, three things to remember. Heating and cooling eat up a big chunk of energy use.

Reverse cycle systems are one of the most efficient options available. And small setting tweaks and smarter habits can dramatically cut running costs. Heating and cooling systems are the largest energy consumers in Australian homes, typically accounting for around 40% of total household energy use.

Depending on the climate zone, housing construction and energy efficiency, this usage can range from 20 to 50%. It is often the biggest contributor to electricity bills. 

That's it for this episode of The Good Energy Guide, brought to you by Ausgrid.

You can  find more episodes on Apple Podcasts, Spotify and YouTube. And  head to our website at goodenergy.ausgrid.com.au for practical tools and resources to help you make smarter energy choices.