AdamfromReigate

Thanks, yes we plan on in screed electric mats. I recognise the lack of future proofing so need to think about that.

Thanks Dan, this is great - I hadn't realised this was possible.

Hi Dave, I had a look and couldn't find a YouTube video. I did also look at their website and found references to infra red heating under an article on low temp heating, but it was overall positive on radiant heating. Could you post the link pls?

Thanks for this. So I get the value of heating the slab that sits inside the insulation, rather than heating the air inside the house. What i'd like to understand better is whether there is a benefit of electrically heating water and then flowing that through the pad, Vs embedding electric pads directly in the slab and heating it that way. Isn't it achieving the same result with the same energy balance but just with less kit? We have high hopes for the air tightness, insulation and thermal bridge free design aspects of the house (fingers crossed), so don't anticipate a high peak load requirement - and hence are trying to avoid over-engineering the heating system.

Thanks JohnMo. Will the custom UVC be much cheaper than the Mixergy 300l? We don't plan to fit an air to water heat pump, as we are not going with wet UFH. I love the idea of a DHW cylinder with heat pump in it. I haven't been able to find any online other than from LG which didn't have any details. I couldn't figure out where the source is coming from - you must need an external loop outside of the thermal envelope is that right? We have put our DHW cylinder at the centre of our hot water users so is at the centre of the house and away from any external walls, so may be tricky. Interesting to look at!

Thanks Jimmyjazz. I really liked what I read about the Mixergy at first and am still considering them and great to hear about positive experiences. The query I put to mixergy was: if my system will be looking to PV divert to DHW, Electric Battery, EV and consumer board how can I make it all work easily? The answer seems to be that the Mixergy own brand diverter would have to be set up with a timer - it cannot work on a priority sequence or user defined logic with other diverters. If you install it with the third party alternative and, say, a MyEddi diverter then that will enable better diversion logic to each load but you lose some of the smart features of the Mixergy tank as the diverter is then bypassing the mixergy logic board. I think this is right but Mixergy seem to have lost enthusiasm to respond now! So the advice from others here to go with a standard UVC but with multiple immersions at different heights may replicate the Mixergy set up at lower cost, less lock in etc....

Thanks for this, super helpful. I will investigate the a2a option. We have a small a2a built into the inlet/outlet side of the MVHR but that will provide a bit less than half of the peak load heating demand, so a second recirculating a2a unit could be a good alternative to direct electric plus would have benefit in summer for cooling as well (particularly if my automated shading plans prove too complex!). Your point about extra DHW volume: I was thinking this was another benefit of Sunamp as 2 X 300l equivalent units would fit easily in the space of 1 x 300l UVC and would have similar thermal leakage when full (despite twice the available volume). I am thinking of this as an emergency upgrade option when the teenage years hit🤣

Thanks for this. We are thinking that the heating demand won't be large enough to justify the capital cost of wet UFH. The residual electric heating should be quite modest. Great to get views on downside of radiant panels. I know they are best installed at height (so cannot be touched and have a larger swept area, 45 degrees arc from edge of panel etc) so was thinking of them for high ceiling rooms. My thinking was that they get the sustain from the objects they hit e.g. the floor if not a human, so no worse than electric pads under the floor (although more expensive per W installed)? And extra benefit of being quicker to react - given the 'turn on the sun and you feel warm' even if the air temperature is still low. Am I missing something here? I really appreciate the wisdom on this forum 😀

Thanks for this. I hadn't heard of Genvex before. The housing system we are using will use a Zehnder MVHR. We will have the Comfoclime 36 unit attached to the main MVHR which adds a modest air to air heat pump for heating and cooling. But I don't think we have the option of integrating the DHW into this like the Genvex can. We haven't yet finalised how much additional heating we will need from the towel rails etc. yet but should be fairly small.

Hello all, I am new to the forum and have been studying a few threads, but couldn't find answer to our question so I thought I'd post it here - feel free to direct me to other posts if easiest! We are building a passive house and now need to specify the DHW tank. The house will have a large PV array, a battery, and direct electric heating (combination of small underfloor pads, electric towel rail and infra red panels). I have been going back and forth between a sunamp Thermino ePV 300 and a Mixergy with a 3rd party PV diverter. I plan to use home assistant which may give me an option of overcoming some of the short comings of each system. I like the sunamp because of its low heat leakage and small footprint. While the Mixergy has better ability to ask it to just heat 30% etc with a family of five and the kids yet to go through teenage years I expect we will be wanting the tank full each day for some time to come. What I like about both of these relative to a standard invented cylinder is the speed at which I think they can recharge from empty to give, say, 50 litres of 40 degree flow at an outlet. Whereas a standard cylinder needs to heat the entire volume both the sunamp and the mixergy should focus all the heating in a smaller volume that you can then use a lot quicker. However I cannot find any data on this. It would be great to get any advice/pointers/opinions on this choice and what I should take into account. Cheers! Adam