Heat Pumps vs. Electric Hot Water Debate

okay today I've got a debate for you we're talking about the difference between a heat pump and a good old fashioned hot water tank with an element in it a real basic one I've brought in Kyle Jensen today from iStore Carl Jensen uh is on I reckon every Forum that you can get that's got anything to do with renewable energy yeah I've been doing it for a long time like yourself so I'm really passionate about the industry and I'm passionate about saving emissions for Australians and saving the money and how long you been working for iStore now uh 12 months and you're a massive advocate of heat pumps and you know for a long time I've been a massive advocate of not doing a heat pump so this is going to be fun it's going to be a good debate let's start off with a really basic um explanation of what we're talking about heat pumps versus elements so that old tank that heats up your hot water that you've had forever unless you're using gas or something like that this is how simple it is right you've got a tank a big tanked like a kettle you know Stan says tall and then you've got an element in it and you have a thermostat attached to it so when when it gets hot enough it switches off that's how simple a tank is and Carl this is why I love a tank is because you know you're an Europe Aircraft engineers your background right you understand that Simplicity just works right yep indeed however uh we're at the point now where the uh the Technology's there to make hot water far more efficiently so um everybody's familiar with air conditioners um not many people have air conditioners fail that often and ultimately they provide hot water with four times less energy than a resistive element can they use about a quarter of the energy which is obviously why the argument the simple argument for heat pumps kind of works but um I think I want to go through all the factors because you know the fact that it uses less energy is and everything because how long do they last and so Carl why is it that every every plumber down to a T and I reckon there's been sort of 10 over the last several years that I've asked and plenty in the last couple of weeks leading up to this debate every single pump plumber hates heat pumps a lot of them thought they needed a refrigeration license in order to be able to install a heat pump which isn't the case um most heat pumps are either all in one or they use hot water transfer via a pump between a separate unit and a tank so they don't actually need a refrigeration license to install one yeah and then second to that is that they didn't have this they thought that they didn't have the skills to maintain them whereas in reality the heat pump itself um will run for 15 000 hours before it's physically worn out and that's the same kind of Lifetime as you've got out of a normal tank and we're talking sort of you know that depends where you are but maybe 15 10 or 15 years you're talking yeah so in Melbourne family of four something around 11 11 and a half 12 years and up here in Queensland probably closer to 15 years so we're talking about fairly big Financial savings would be the first point but we need to talk about the cost of the tank but we'll get that to that too and your biggest reason for heat pumps is more about the environment absolutely so uh last year Australia's emissions didn't go down they still climbed and Australia's Got 11 million households 11.5 million households which is a hell of a lot half of those are using gas to heat their hot water in the other half are using resistive electric elements and we can reduce Australia's emissions by around 10 if we take all of those old Technologies out and replace them with a pumps you know and I'm probably not even going to argue on this point I reckon even if I said that a heat uh heat pump lasts half the time of a tank which I'm not going to go that far uh then you win the argument the environmental argument hands down anyway right so if you're buying a hot water system for environmental reasons and you're not too concerned about financials I'm going to agree with Kyle and just say get a heat pump but I think there's a lot more into it to that not everyone just buys you know throws extra money out for environmental reasons okay yep I don't disagree on the same token um you know we talk about batteries a lot in our industry as well um a heat pump or any hot water service can be considered the same as a battery because we can use it as a solar sync during the day yeah put energy into it and then use it later on at night obviously resistive electric beats gas in that scenario because you can't use solar system to generate any gas but we can use it to put energy in the hot water service so we've got if we've got an abundance of cheap solar energy then resistive element doesn't look so bad yeah exactly exactly and we'll sort of get into that and I think that might be a little bit where we differ um so okay I'm just let's talk about the different factors and I've done up a calculator we've both put in our figures here and we're going to show it up on the screen as we talk um I'm gonna by the way I'll put this um calculator online there'll be a link below and it'll be in my blog it might do a little bit of a Blog about this debate as well but if you want to use this calculator to put your own figures in you can get to it but what I want to do is talk about the main factors so one of them is how much hot water do you use right so very important yeah so ultimately um Australian standards is that everybody uses 50 liters of hot water a day so I'm going to start inputting our figures into the um this calculator as we go along and we are only using seven kilowatt hours a day take in mind we're in Brisbane the water isn't as cold up here down in Melbourne indeed now let's divide that by four if you're using a heat pump simple maths we both agree on so you'll use 1.75 kilowatt hours of power a day okay now the other factors that come into play is the price of power so the price of grid power we're just going to set this as standard over the next 10 years obviously who knows whether compared to your wages electricity is going to go up or down but we've agreed that we're just going to look in a price ultimately as the cost of energy goes up a more efficient devices and more efficient means of using energy becomes more and more cost effective yeah but you're you're going to concede and you're just going to go along with me and say we're just going to call electricity even you can jump into this calculator and put your own figures in if you want with the link below but solar feed and tariff I'm going to say eight cents we've agreed on that you know number the percent that it's supplied by solar so I've got at home I've got 17 kilowatts of solar I've got a fronius hot water diverter so what that does is it says um okay I'm sending back one kilowatt back to the Grid at the moment no no we're going to send that to the hot water tank now I'm sending three kilowatts we'll send that to the hot water tank so it follows your X excess and effectively all it's doing is saying I'm only sending excess solar power to my hot water tank so because I've well I didn't pay for this but because I've got the luxury of having a really expensive hot water diverter um in my case I'm using I would say 95 of my hot water is heated by solar power I'm going to say and I'm going to be a little bit generous in my case and say that if a customer puts a catch relay in which is a smart timer let's just call it right so so the the hot water turns on when you've got enough Surplus solar power but it doesn't follow that curve I'm going to say that 80 will be heated by solar okay sounds good we're going to keep on going down and uh the cost of the tank over 10 years now this is interesting Carl so how long is uh life store Gonna Last istor's been in the market already for eight years we've used the same tank manufacturer for 12 years now we've never had a tank failure never had a tank failure okay okay but what about so this is my um simple grief I guess is a heat pump is basically bolting an air conditioner onto a tank uh and then expecting that heat pump to last what are you saying 12 15 000 ounce yeah yeah 15 000 hours which is 10 to 15 years or something yeah we've got them installed in commercial applications as well and things like um hotels and in those scenarios where they're running a lot more um the warranty is 15 000 hours so we can use that in five years if you want right okay sure so it really depends use case on use case okay so what I'm going to do here and in my calculation I'm going to say that uh ice door heat pump is going to last 10 years sure which is double the length of the warranty which I think is sort of fine yeah and I'm going to say a tank tanks used to last um 20 25 years over prepared one you pointed out to me that was a good old copper tank yeah um and when I was talking to my mate Julian well we were both talking to Julian Saxby who's a expert solar uh hot water installer and repairer so he's got a lot of experience on fixing these things you know he's sort of saying yeah agreeing with you that maybe maybe they're not lasting as long and I'm going to go out there and say 15 years I go so far as to say even if the heat pump did fail there's a backup element there and if you couldn't afford to replace it it was physically worn out you've made your savings three times over and if you made your savings three times over you can buy another one but if you can't there's an element there and it'll last just as long as your electric element yeah exactly that is that is a really good point I think let's say I'm right and your system a thousand ten years and my system fails in 15 years what I'm saying failing I'm only saying about the heat pump part the air conditioner that's bolted onto the side sure you've still got an element down the bottom and as long as that tank lasts it's going to last as long as mine theoretically so it can last 15 years anyway won't be running as efficiently you'll be going old school like me we'll be using four times as much energy yeah yeah and uh if power bills will go up so you might want to go and buy another one at this stage okay so um we've put in put into our calculator our differences there 10 versus 15. um I'm going to throw in here that I need to put a hot water uh diverter on there or not a hot water kind of like a timer which is a catch solar relay I'll link to a video explaining what that is up there but basically like I mentioned before it's a smart timer uh that will come on and turn on when you've got enough but let's say then you go and turn on your oven or a cloud comes over it'll see that you're not sending enough power off so it'll switch the system off and on and so my calculation is saying fourth hot water including the tank including the the relay and everything like that that catch relay is going to cost the customer four thousand three hundred and ten dollars in 10 years for the heat pump it's going to cost 4152 so obviously those figures are so so you win by 200 bucks there's not much in it you know that's just so arbitrary but basically about the same right um with my figures of using fairly conservative amounts of hot water and rigging all the figures in my favor right sure in Brisbane cold water inlet temperatures warmer uh you don't need this longer shower uh you have more sun available for your solar system oh man don't tell Carl but I actually just found an error in my formula uh the cost of old school hot water was more like 5 600 was over 10 years so Carl wins even better but let's go on to your figures um and we'll go we'll just go through this really quickly right we understand how our calculator Works you're going to say 14 kilowatts 14 kilowatt hours in uh in Victoria for sure yeah you've got to keep the people in the house 200 liters of hot water a day yep sure and that's that's another way of looking at it it's fair right and so if you're doing that with a heat pump you're using a quarter of that three and a half kilowatt three and a half so three in summer and four in Winter and that's just because the cold water inlet temperature in Winter is 10 degrees cooler uh you're going to agree with me on the price of power as we've said now what do you think is realistic for um the percentage that you're going to do if you're installing a resistive tank and a catch relay or a timer or something like that yeah in Victoria it's much less so we have 180 days of overcast weather a year and in overcast conditions in Victoria are a solar system will only make 1.3 kilowatt hours per kilowatt installed on the roof so if I had a five kilowatt solar system in Winter it'd only make six and a half kilowatt hours whereas yeah in Brisbane up here what system or six kilowatt system yeah yeah we're still doing way more than that you know 15 kilowatt hours for that sort of um uh you know even in winter so excuse me the economics enormously excuse them massively so you're going to say you had put in here 0.7 I reckon that's a little bit too generous on my side okay for Queensland 0.7 we'll we'll give you that down in Melbourne I'd say it's more likely 0.2 you're yeah okay point two right but you're going to be generous on this right because it's going to work for you anyway yeah yeah we're we're good we're uh generous with with everything okay and in my we won't explain exactly how we've worked this out but you're gonna say 12 years okay and versus maybe 15 years from a tank we're still talking fairly similarly right so pretty close um yeah okay so uh the cost of a timer for me you've still got to throw that cost in the 800 bucks now this is interesting check this out the difference in price so for hot water if we were to do it with your maths cost of my hot water is going to cost me pretty much eight grand seven thousand nine hundred bucks the cost of your hot water drum roll is gonna cost just over half that four thousand eight hundred dollars pretty compelling case uh so um I didn't think the numbers would be as different Queensland to Melbourne but I'll definitely accept that because the sun shines here yeah yes exactly doesn't it Melbourne just to add insult to injury I made the same same area here it's more like nine thousand nine hundred dollars for 10 years for old school hot water so Carl off really enjoyed this last week thinking through this and talking to people that I respect in the industry Julian Saxby and I've got to give him a plug from Brisbane solar repairs uh who works in Brisbane a great heat pump Advocate um and I trust him because as I sang before he does a lot of maintenance on systems so he gets to see what goes wrong with different systems he's a big fan of iStore compared to other heat pumps I've got to say as well look at the end of the day the eye store is built to be a tractor it's a very simple machine it's the simplest form of uh heat pump that you can get has an AC induction motor which is very simple the same as your swimming pool pump yep everyone's familiar with and in terms of its design it wraps the evaporator coil oh sorry the condenser coil around the outside of the tank which means that there's no heat exchanger it can get calcium buildup and there's never any chance that a failure of the heat exchanger would put gas or compressor oil into the water so it's very safe and there isn't a uh a simple heat exchanger it's physically wrapped around the outside of the tank so it's tough to see that wearing out Carl I think we have a we're not here so ultimately um you know everybody's probably seen me on socials and they uh I know that I'm a bit a big advocate for electric vehicles because they're just so cheap to run and there's so little maintenance so anything that we can do to accelerate the transition and save people money so that they can get to that end goal of having an electric car is uh is of advantage and if we've got something like a heat pump that can save the same amount of energy as what their electric car uses every day we really are transforming Australia's Energy Future yeah I guess where my mindset and I've sort of reflected on why I've been stubborn about this is that I've seen a lot of heat pumps come and go right and plumbers hate them and part of the reason that plumbers hate them is cheap rubbish heat pumps are installed and they fail you know this was also before solar so before we could throw in the figures of solo and you know and get the whole picture together as we have now I think we're living in a different age where heat pumps have developed especially if you're dealing with a decent brand like I store they're not going to foul on you in three or five years like they maybe used to I'm sure Mark you've read the book by Saul Griffith called the big switch and that is the goal of electrifying everything that we do so we've got a lot of gas in use in Australia half of the hot water services in Australia are fired by gas and obviously you can't make energy with your solar system to feed a gas hot water service so anytime you've got a gas hot water service should definitely change it out for a heat pump yeah I'd totally agree with that like even on my conservative figures which are pretty even I reckon switching to a heat pump anyway just for environmental reasons even if you don't want to pay for that well you're not really paying more even on my numbers so so thanks for coming Carl all right I reckon we should head out for lunch eh absolutely okay thanks for having me thanks man

Channel: MC Electrical

Views: 88,931

Keywords: istore, heat pumps, karl jensen, mc electrical, hot water tanks

Id: Mz2QaWodrzw

Length: 17min 12sec (1032 seconds)

Published: Mon Aug 14 2023