Hello from a newbie - one with a Mixergy tank

[BristolBill]

Hi everyone,

 

a quick intro to say hello.

 

More a renovator than a self builder and very much at the end of a project to make an 1870s Bristol house suitable to keep us here for at least the next ten years with a growing family.  With a 2 year old and a now a two week old I had as an objective to reduce the carbon footprint of our energy use.  The project was principally a single story extension to make a kitchen diner in addition to various changes to other rooms such as a bathroom with some walls coming out in the process.  The opportunity was there to move the boiler and having had one too many showers turn cold with another tap being used, I decided it was worth doing something to the water system in toto.  This is where I owe this forum and certain contributors a huge thank you as I learnt a great deal from them whilst trying to decide where to go with the spec although it didn't quite follow the original plan.

 

The house is a narrow terrace with a couple of rooms on each of three floors and is topped off with a butterfly roof so less than ideal for solar.  So why join the forum now?  Well the principle threads I followed were around hot water and we've ended up with a 4kw array on the more favourable pitch, a Powerwall 2, and a Mixergy tank.  This last part I see mentioned here quite a bit so wanted to offer a bit of user feedback to those considering one if that might be useful.  There was much to'ing and fro'ing before arriving at this setup and the original intent had been a Sunamp Uniq 9 or larger.  Various things conspired to drive the spec as it stands and we're only in the first few months of use.   Very much learning as we go.

 

I hope this finds everyone well in these times.

 

Best,

 

Billy

 

 

Edited May 3, 2020 by BristolBill

[ProDave]

Hi and welcome to the forum.

 

Please go and start a thread about the mixergy tank.  I think we have discussed the theory but it will be good to hear from a real user of the product.

 

[Dan F]

Welcome! 

 

I'm also interested to understand your experience with Mixergy.  We haven't quite started our build yet, but were also initially looking at Sunamp but are almost decided on Mixergy.  How are you heating the Mixergy?

[BristolBill]

Of the many options I have the following:

 

1) an indirect coil to a system boiler that I try and avoid using to burn less gas.  The tank has authority to control the call for heat.

 

2) an electric element also controlled by the tank.

 

3) an electric element linked to an eddi diverter.  This is co-located with the other element. 

 

There is a third element at the bottom of the tank as an emergency standby.  Unwired.

 

As far as the tank is concerned the management of the 'hot layer' is independent of heating source.  It just injects water from the bottom of the tank to grow the hot layer as you heat it.  You can set the target temperature in the app.  I currently have a target temp of 60°C.  If the tank is being heated via the Eddi the cut off functions at about 75°C.  Instead of a blending valve near the hot flow we have them where required elsewhere.  Can catch out the unwary at the kitchen sink.