@transparent Morning. Just put a lengthy post on the ASHP forum. The house is 650m2 and very well insulated (although not to passive standards). We have two Nibe F2040-16 in cascade.

@jarlatheoin do put the MVHR in early it’s not an easy retrofit. Even if you save on the unit itself the ductwork is what is difficult to retrofit. Put in UFH pipe work with 100mm between pipes, and larger radiators for low temperature heating flow then you are ready to put in ashp whatever you decide near term. AsJames says don’t put in extra zones and active heating thermostats, since they will be obsolete for an ashp, and hence waste of money.

Solar PV definitely yes, the satisfaction of free electricity is great, the payback time is ~6-7years. No-one thinks power prices will come down much within that time. But easily retrofitted.

Hi, I'm Rich...

I have a Steibel Eltron GSHP (the one at the top of the table here)... https://heatpumpmonitor.org/ I live in beautiful Mid Wales and I also have Solar Thermal, PV, 2x EV's and loads of Battery Storage (some of which I built from Tesla Model S batteries, and other bits I have bought). I'm also a big Home Assistant user.

I used to do forums years ago, but not something I've done for a long time. I've been on a few Renewable Heating Hub videos and I'm in the new book. I love all things renewables and have done for the past 20 years.

Looking forward to contributing where i can @editor and being part of the community. 🏴‍☠️😎

Welcome in, @pirate-rich. Glad to have you on board and looking forward to hearing more about your setup.

Ahoy there, Captain @Pirate_Rich 🏴‍☠️⚓️ Welcome aboard!

For anyone who doesn’t know, Rich (Richard) isn’t just a fellow renewable enthusiast… he’s a full-blown controls geek. He’s been on the Homeowners' Q&A podcast several times, and every single time he drops pure gold that homeowners and installers can actually use.

So we’re absolutely chuffed to have you join the crew here on the forums and I know you’ll be a huge help to our community, and I’m looking forward to seeing your posts pop up all over the place.

For anyone curious, here’s the latest podcast episode Richard was on recently... well worth a watch (Richard's the one on the right of the thumbnail):

Posted by: @majordennisbloodnok

↑

Welcome in, @pirate-rich. Glad to have you on board and looking forward to hearing more about your setup.

Thanks for the warm welcome @editor and can't wait to be part of your brilliant community! 🏴‍☠️😎👍

Hi. I'm Iain. Our 1980 chalet bungalow in Shropshire has a mix of UFH and radiators, and is heated with a tepeo ZEB, with hot water from a Sunamp Thermino. There is a battery, PV and a couple of EVs as well. The house is an ongoing project, so the next thing I'm looking at is an air-air heat pump for summer cooling...

As I understand it @wully - the Tepeo ZEB is basically an electric boiler.

Thus the COP is 1

But if you have copious amounts of low-cost electricity from your own solar-panels...
plus importing from the grid on a ToU tariff...
and a sufficiently-large storage battery...

then a ZEB can be a great solution.

My next question is whether you have 3-phase from the grid?

Hi @transparent. Yes, and no.

The ZEB is not an electric flow boiler, that consumes electricity at the point in time when you need heat, nor is it a traditional storage heater.

It is a dry-core heat battery, that consumes electricity when it is cheap, and stores it as heat. That heat is then delivered to the hydronic heating system when called for by a thermostat. So while the CoP is indeed 1.0, as I have a time-of-use electricity tariff that means that the heat I use at 6pm in the evening cost me 7p/kWh rather than 27.8p/kWh, equivalent running costs to a CoP of ~3.9. And no need for a 3-phase supply; an 80A or 100A single-phase supply is sufficient to charge the ZEB and other clean tech overnight.

The ZEB can be a great route to decarbonising heating for those apartments and smaller homes that are challenging to install a heat pump in. The majority of homes in the UK are suitable for a heat pump, and should get one. For the rest there needs to be alternative solutions, and a heat battery can be one of those alternatives.

For full disclosure I work at tepeo. But I like to think I can be objective, and I'm happy to talk frankly about my lived experience with my ZEB and Thermino. Is there an appropriate sub-forum for thermal storage?

Posted by: @wully

↑

Is there an appropriate sub-forum for thermal storage?

There soon will be...
... because we'd very happy if you would start one 😉 

My comment about your 3ph requirement was related to you having two EVs.
Apologies I could've been clearer.

The present threshold at which your DNO is likely to require you to migrate to 3ph is 60A.
That's technically called an Engineering Recommendation.
It is a standard, but there are circumstances when the DNO's Planner for the area can decide differently!

@wully Yes, by all means, start a topic as it will be of interest to many I feel sure; I have an ASHP but due to space restrictions also opted for a Sunamp Thermino ePC210. We have 8.1 kWp of solar panels, 27 kWh of Powerwall, a MyEnergi Eddi and are on the OE Cosy tariff. Regards, Toodles.

Posted by: @wully

↑

The ZEB is not an electric flow boiler, that consumes electricity at the point in time when you need heat, nor is it a traditional storage heater.

It is a dry-core heat battery,

Sounds interesting. 

According to the website the capacity is 40kWh, so assuming you have cheap electricity for 7 hrs per day and can both charge and heat simultaneously (can you?) its enough for a home with a loss of 2.3kW.  Whilst charging plus heating you would be drawing 2.3+40/7 = 8kW

I suspect that there are plenty of flats with <2.3kW loss, not least because flats have a small area of outside wall.  Weight 375kg with an area 0.6mx0.6m is 1000kg/sq m, which well exceeds what I understand to be the typical design loading of between 1 and 2 kN/sq m, thus probably not structurally suitable for a flat other than on a ground floor.

Have I missed something and if not whats the target market?