Mrjmegson
Well-known member
Yeh definitely go for an Eddie if you're getting a Zappi. Totally agree.
But also definitely get a Mixergy tank, they sound incredible.
But also definitely get a Mixergy tank, they sound incredible.
Immersion boost with Tesla Powerwall
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johnb2713
Well-known member
I'm not convinced about the logic, why would I only want a tank a quarter full of hot water? If I'm using solarPV and/or off peak, fill it up completely. The heatpump ready bullet point is really a nonstarter, heatpumps use the indirect coil just like the gas boiler. Their 20% saving is only valid with a gas boiler thats cycling on and off and its an 'up to' 20%. I suspect the tank would be very expensive too, for something that offers no advantage in my eyes, I dont care about being able to heat the water up from my phone, all I want is when I turn on the shower, hot water is there.
I had a new standard insulated tank installed when I needed to fit an immersion heater ready for the solar (the old tank the immersion was u/s but seized in). Looking at the EDDI data my tank appears to lose less than 15w when the water is at 85 deg C. I run it at high temperature and have a blending valve on the exit to drop the temperature to 50 degC. I may install and extra tank after I've run with my second battery for a while, hot water cylinder does work very well as an energy store.
Mrjmegson
Well-known member
Totally valid points if you have lots of excess solar to heat all the water in the tank as an energy store, but that's not the USP of the Mixergy.
The idea behind the tank is economy, when you don't have bountiful PV energy.
It heats from the top using stratification, or thermoclines, and only heats what you need, which it learns. It has a control unit that learns your habits, as most people are habitual with things like showers. I have a shower at 1930 every night after we put our wee man to bed, and the Mrs has a shower at 0800 every day after breakfast. She uses 50L of water on average for her shower, so the tank will make sure it has a minimum of 50L of hot water ready for 0800 every day, and a staggering 100L (I loooovvvveee a shower) of water ready for me at 1930 every evening.
It's built in solar diverter will of course heat the whole thing with your excess solar, you can boost it when ever you like, it will hear direct from the mains, or from a gas boiler or heat pump, so massively flexible.
As you can tell, I'm a bit of a fan. Lol
The idea behind the tank is economy, when you don't have bountiful PV energy.
It heats from the top using stratification, or thermoclines, and only heats what you need, which it learns. It has a control unit that learns your habits, as most people are habitual with things like showers. I have a shower at 1930 every night after we put our wee man to bed, and the Mrs has a shower at 0800 every day after breakfast. She uses 50L of water on average for her shower, so the tank will make sure it has a minimum of 50L of hot water ready for 0800 every day, and a staggering 100L (I loooovvvveee a shower) of water ready for me at 1930 every evening.
It's built in solar diverter will of course heat the whole thing with your excess solar, you can boost it when ever you like, it will hear direct from the mains, or from a gas boiler or heat pump, so massively flexible.
As you can tell, I'm a bit of a fan. Lol
johnb2713
Well-known member
It seems like a solution trying to find a problem. Do you drive your car with just enough fuel to get to your destination?
I enjoy my shower too, hot water always being available not just at set times. What happens if patterns change, unexpected guests etc? Not exactly massive savings from an expensive product that gives no advantage other than a potentially small energy cost saving.
I really don't see the benefit of only heating the water you need apart from tank losses which are minimal. it may as well be replaced with an instant water heater 10kW like an instant shower.
Mrjmegson
Well-known member
Lol, you really don't like this system do you.
I think I said earlier, you can boost it if needs be, or you can set it to be like a conventional tank if you need to.
But the idea is that you only heat what you need, saving you money if you're running it off the grid.
If you have an abundance of solar, it will heat the whole tank.
If you're at home all day, using hot water at lots of different times, it will learn that, it will learn how you use it.
It heats up very fast too, can't remember the stats, but if you decided you want a shower and there is no hot water, you wouldn't have to wait long.
Anyway, we are going round in circles now, so let's leave it at I like it, you don't.
I think I said earlier, you can boost it if needs be, or you can set it to be like a conventional tank if you need to.
But the idea is that you only heat what you need, saving you money if you're running it off the grid.
If you have an abundance of solar, it will heat the whole tank.
If you're at home all day, using hot water at lots of different times, it will learn that, it will learn how you use it.
It heats up very fast too, can't remember the stats, but if you decided you want a shower and there is no hot water, you wouldn't have to wait long.
Anyway, we are going round in circles now, so let's leave it at I like it, you don't.
johnb2713
Well-known member
It's not a case of not liking it, its a case of I really dont see the point or any advantage for what I assume is an expensive piece of kit.
So no advantage there really is there?
My tank loses 0.45p - less than one penny per day in thermal loss assuming I use peak rate power to heat it. Off peak and solar will make it even less. So where and how is this white elephant going to save me money?
Again, no advantage here either
But really how is that an advantage? it really isnt.
I dont have to wait at all with my old fashioned system that costs next to nothing in losses. I really dont see any advantage of this system compared to EDDI and a conventional cylinder.
As I said youre preaching how wonderful it is yet all the points you raise don't stand up to scrutiny.
As I'm sure you will appreciate, I'd give a salesman a tough time on this one LOL.
Keep trying, you may find an advantage somewhere.
Just changed my order from PV panels plus Tesla Powerwall to PV panels, with solaredge isolators,solaredge battery and EDDI.
I’m still not entirely sure how the EDDI will work in my situation. Currently have gas boiler that heats large water cylinder and in winter provides the hot water that circulates in my wet underfloor heating on three floors.
I’m still not entirely sure how the EDDI will work in my situation. Currently have gas boiler that heats large water cylinder and in winter provides the hot water that circulates in my wet underfloor heating on three floors.
johnb2713
Well-known member
I assume you have a hot water cylinder and an immersion heater?
Assuming you do, EDDI has the ability to dump any excess solar energy into the immersion heater making good use of the excess energy you have from your roof.
Yes I have cylinder and immersion although currently have never used the immersion always used the gas boiler. If using the EDDI would the hot water tank always have to have the immersion switched on? If so then if the EDDI only partly heats the tank I am back to grid electricity heating the tank rather than gas.
johnb2713
Well-known member
Using off peak electricity it’s a good bit cheaper than gas to heat the water. My EDDI is configured to switch the immersion on between 00:30 to 04:30, it then switches off until there is excess solar available. The EDDI unit sends all of the excess solar to the immersion between 100w and 3kW until the hot water tank is heated. It’s very efficient in that it can use 100% of excess solar up to the max wattage of the heater and it can also control a second tank. Setting priorities is easy from the app it’s an absolutely great piece of kit.
Ok,I don’t have off peak tariff as on fixed tariff till Mar 24. In summer months I could use the gas to heat say night time and EDDI to switch on immersion during daylight hours to top tank up and minimise gas at nights. Winter as I have to have gas on for underfloor central heating it and the EDDI can heat the water hopefully reducing gas. Or as solar energy will be much less divert any excess into battery for evening use.
johnb2713
Well-known member
You have the complete flexibility to run it however you want, you can set priority to hot water first or battery first etc.
Some energy suppliers dont have a penalty for early ending a tariff, Octopus is one of them. My peak and off peak are 29.2p and 7.5p respectively, the battery is a huge money saver by charging up during off peak and then throughout the resulting in very little peak unit use.
