This is the number one factor in our lives it seems. Kids as well. I can do lukewarm.
So true! Get a name brand and be happy.
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10 000 years ago, a woman looked for a man that could protect her and the kids from natural dangers. Now she’s looking for a man that can pay the heating bill!
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Would be intresting to see how the spreadsheet compare if you also add a heatpump option vs gas ans normal electric.
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OK fine. This I do simply by dividing the (e) cost by 3.5 (which is roughly the COP of a heat pump). And I made it a bar chart.
The heat pump is indicated as (h).
gas-vs-electricity.xlsx (10.1 KB)
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My intrest was purely for bragging rights. 
With some of the gas installation costs quoted above being more than what I paid for my heatpump install 4 years ago, I am very glad I made that choice.
The only “maintenance” I had to do up to now is to wash the bottom tray clean from alge and dust. 5min diy job.
Lugging gas bottles up the hill and steps where I live would not have been fun.
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One thing I think a lot of people forget is that using gas also helps to diversify your energy usage making one less reliant on one single source.
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What I found, having had EV tubes for 9.5 years, after having had a look at heat pumps to replace said EV system, the costs involved after having enjoyed the savings for 9.5 years, did not add up.
On top of that, a heat pump with maintenance, info obtained from various suppliers, would not last 9.5 years.
So I got 4 more panels, 2kw elements “en basta met dit alles”. Their is no cheaper way I know of, If you have a system in place already, to heat water.
If I had NO system in place, hell, I would got for a heat pump first!
Cause EV tubes, they don’t make them like they used to.
It probably depends. My neighbour, where I used to live, installed a heat pump around the same time I installed the SWH. Around 7 years later, it needed work done. The same unit came back however, it was not replaced with a new one. It was an ITS unit though, which is the same as the one I have now.
I had several York air conditioners too, which work overtime in summer. They were there when I moved in in 2010, and they were still there, without even requiring any gas added (only cleaned the filter occasionally) 9 years later. Since a heat pump is essentially an air-conditioner that puts the heat into water, I conclude that 7-10 years is probably what one can expect.
In that time, two Kwikot’s will have bursted… which is also the weak point of any retrofit system (such as mine). That is the part that is going to fail and cost money…
Agreed.
2nd hand ones I found on Gumtree needed extensive maintenance. They where 5 years old. That is what triggered me to phone around a bit.
Both my aircons leak gas. 
Fact that the EV tube system lasted as long as it did, surprised the both the accessor and plumber.
So I agree, it depends … on what “day of the week” model one gets. 
A heat pump is not equally efficient when it’s cold outside right?
Correct. The COP comes down when it gets cold. In our area of the world, where we rarely see temperatures below 5°C, it’s not something you have to worry about too much 
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It’s also not very efficient if you want to get very hot water. Takes a lot longer to heat the last few degrees and mine is set to 55 I think.
Yup, I feel that lately. I’m the last guy to take my shower in the evening. Even with a 200-liter tank, I end up with a lukewarm shower towards the end. Some combination of water mixing and the time it takes to heat. But it’s still fine for a 4-person household. And I still have gas as a backup.
I have found it is worth while to match your shower rose/head with your geyser. That would make even more sense for a gas geyser.
I have a 150L geyser with heatpump. It works fine for showers for 4 people if they don’t open the mixer full throttle and keep with the idea of saving water. That is something the regulars can be taught. But with visitors that is not so easy.
We have a sewage tank that must be pumped and I found it was filling to fast to my tast. So I did some tests up swopped the shower rose with a water saver version to save on waste water, but this had the knock on effect that we can all shower much easier now and a tank will even last for 6 people or more.
Intrestingly those shower heads that claim to be water savers are not the most effecient. I found those cheap showers heads with the small holes works best.
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Depending on the model. Most heat pumps can only heat the outlet water to a maximum of 60 deg. ITS sells a Super 5kw that can heat the outlet water to 70deg. It uses a different refrigeration gas that can run at higher degrees.
We are doing exactly this on one site. The client is using a Evac tube system to heat the water in a normal geyser, he installed a Rinnai (Intelligent) gas geyser. If the water feeding the geyser is over 55 deg, the gas geyser does not switch on. Should he experience a cold cloudy day and the evac system only reaches 40 deg, the gas geyser will only top ut the temp to 55 deg. In effect, he is only using the gas as a backup.
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That’s the idea, based on cost though. We have one quote at “18k”, gas guy got back to me and asked what do you want to pay . Take it it is negotiable. My own calculation came to 10k based on:
Gas Geyser R5000
Gas Cage 19kg - R2000
Gas and Plumbing Install R3000
Waiting on a call from Geyserwise to merely upgrade the existing 2 panel system. As mentioned before, try to make the best of the system you have haha :). Will get back to you on what they have to say.
We have one similar to this:
Cape Town, we all about the water saving. Even after the fact.
