MikeGrahamT21

Currently the unit is set to stop delivering power when it hits 10% SoC, and when the unit drops to 7% SoC (which happens quite often as my current model of inverter is powered by the battery ONLY) it does a force charge at 300W until it hits 10% again and so on. It does slow the charge as it nears 100% SoC as part of the battery firmware. Otherwise the ToU settings allow an Amp Charge and Discharge to be specified (which allows a low and slow charge which reduces wastage), but nothing more other than the time slot. I suspect the fact it charges to 100% probably doesn't help (i'd have to take a wild guess at the Amps and timespan to stop it going all the way), but again this particular model of inverter doesn't have the setting to stop it going above, say 90%. The Generation 6 Solis AC Coupled has all of the relevant features needed, but this would require spending yet more money, so for now its staying and when/if it dies, i'll see whats about at that point

With Octopus yes, but not with Eon, you have to use the bundled gas tariff so its not as flexible. Cosy/Go type tariffs would require ASHP or an EV, both of which I don't have, so that limits me just to flux, which was OK, but became rather expensive.

The degredation from grid charging was quite extreme, i'm down at 94% SoH now, which hasn't dropped a single percent since stopping charging from the grid. There is only 3-4 months of the year where the battery isn't useful, although that would likely be shortened if it were sunny, the gloomy weather hasn't helped. I'm locked in with Eon until this deceber, so can't do anything until then without paying fees, and i'll re-assess when the time comes. The trouble with the ToU tariffs is that you are instantly paying more standing charge for both electric and gas, and they stick you on gas rates which are quite high (they used to be much better), so that along with battery degredation it becomes less and less economically sensible. There is also the losses to content with too from conversion from AC to DC and back again, they are materially significant.

Yeah probably worth checking, can't see it being any different to it being sat on a shelf in a warehouse however? Have just done a quick google, and it seems they can, but actually need greater than 90% charge Pylontech US3000C batteries can remain disconnected for up to 6 months without needing a charge, provided they are stored at a high State of Charge (>90%). They have low self-discharge rates, but should be checked and topped up every 6 months to prevent the voltage from dropping too low.

Always a useful page i tend to use: https://www.moneysavingexpert.com/utilities/best-solar-rates-seg-tariffs/

Yes i noticed that the other day whilst searching, you can't be using one of their smart tariffs which is a bit naff, though I'm on fixed currently, was seeing how much difference there was between charging and not charging the battery over winter (taking into consideration battery wear which for some reason was quite high whilst grid charging, yet haven't lost a percent since just charging up from solar, almost a year, put me off a little from grid charging), and I think if I go down this route again which I may well have to, it might be wise to charge the battery to 50% in november and then switch the system off until mid Feb, as its consumed around 1.5kWh a day just topping itself up to the minimum charge, not ideal!

E.on's tariffs have also dropped, I moved to them from Octopus last August, for 16.5p/kWh, but their new tariff which I'll move to this August is now 13p/kWh 😭

You absolutely could, the ply would need to be screwed down in a tight grid format, through the insulation and into the floorboards. Ensure you aren't going all the way through in case of pipes/cables etc. Alternatively you could use something like a Marmox board along with their fixings. Any reason for not taking the floorboards up and insulating between the joists?

So you are saying the bulk of the price is for the initial install and those bits will remain viable for another HP? I guess if thats the case then a replacement HP would maybe only be slightly more expensive than a gas boiler, but would save money in long run (as long as electric prices come down). I wonder how much a company would charge to do all of the work for a replacement unit?

Does anyone worry about the thoughts of replacing the heat pump should it fail? Have just had a look at Vaillants which seem to have 7 year warranty, vs their gas boilers which have a 10 year warranty. Obviously the first install with conversion from gas/oil/lpg gives you the £7.5k grant, but if it should fail out of warranty then essentially its full price for another, the thought of that scares the hell outta me having one. Appreciate in 7 years time they maybe a lot cheaper, but only maybe.

I'm still curious if wet plastering the tape in would save all this parging and excessive taping? Or would these areas be lined with plasterboard? Living in a 60s bungalow, the 'cavity closers' on my place are L shaped blocks, so the whole reveal is solid and therefore wet plastered

And the benefit of air filtering too

It’s a good job the date is on both of those photos 🤣 Congrats, enjoy the fruits of your labour!

Totally agree, I suppose you can’t really show off low energy bills and great IAQ 😂 the lady I was on about doesn’t believe in climate change, she tells me that it’s a natural cycle, but I suspect a lot of it comes from her favourite TV channel, GB News

I mentioned it to one of my neighbours who is always going on about getting triple glazing despite having huge holes in her floor which she isn’t bothered about. asked her what she thought to the program and she said…why are they messing around blocking all the holes up and then putting a machine in to pump air around, isn’t that what a chimney is for? 🙈 😫 I enjoyed it but like watching his programs on anything, his enthusiasm is great and also speaks my language (Yorkshire), a good intro to passive house for the uninitiated, I doubt people will be rushing out to upgrade any time soon though, majority see it as unnecessary, and that it’s on the government to bring down energy prices.

Would it make a difference if the blockwork was being wet plastered? Fully embedding the airtight tape into the plaster. This is what i did, with the fabric type tape, was what the guidance suggested was the right thing to do. Blocks were primed with airtight primer before the tape. Just curious really, not much i can do about mine now if it is wrong lol

Looking at the bare side, to me it looks like wood fibre board, its entirely possible though the texture on the other side could be artex which could contain asbestos, get a test done and you'll know for sure

Any photos of the other side of the board? (Loft side)

So after around a week with the new fan speeds, it’s got the exhaust value down a couple of degrees without changing the supply temperature so that’s good, but the supply is still warmer than the extract. decided to get the thermal camera on it and it gives a similar reading extract pipe supply pipe observe the centre value as this was pointed at the plastic PVC pipe which is same on both and not reflective

I think you were right! Revisited this today. When i originally balanced it using the loan anemometer, was middle of summer, super dry and I’d just installed brand new filters into the Cleanbox which clearly had a much lower pressure drop compared to middle of winter when they’ll be holding a bit of moisture too. The figures i put up above i got wrong, they were 35% extract and 36% intake at normal speed. Got the specs up of both units and ran it all through Gemini which gave me figures of 42% intake with 35% extract at normal speed, and 59% intake with 50% extract at boost to compensate for the pressure drop. I’ve knocked a couple of % off of the normal extract speed in order to get the intake down to 39%, which suited the extract being at 32% apparently. I suppose this would be where a constant volume unit would come in handy which would sort itself out. So yeah, thanks for seeding the idea, I’ll keep an eye on temps etc and see if that cures it, I clearly didn’t leave it long enough the other day when i was messing

For clarification for my unit: Ext - External - Temperature of the fresh air coming into the system Exh - Exhaust - Temperature of the stale air once it has passed through the heat exchanger Int - Internal - Temperature of the stale air coming into the system before heat exchanger My unit doesn't have a supply temperature sensor, which is why i added some of my own, but they were only cheapy

Out of curiosity earlier I changed the fan speeds to 40% intake and 30% exhaust and it made absolutely no difference at all, temperature stayed identical on all including the controller of the MVHR, I left it that way for a good two hours as well, have put it back to how it was previously now. still curious as to what other peoples MVHRs are showing temperature wise for comparison?

I balanced it all last year and got both extract and supply at the same overall values, so should be fine on that front, and the fan speed is set to the same, 35% normal and 50% boost

No heaters in situ and like I said I’ve swapped the thermometers around and the error always stays the same, yes they are defo labelled correctly, have checked a million times myself months. They are only cheap thermometers agreed, so how about the readings from the unit itself, do they seem right? I’ve just nothing to compare against and this is the only MVHR I’ve ever owned.

Hi This has been bugging me for a while, but I’m still not sure if anything is wrong as I’ve nothing really to compare it to, but one thing stands out as odd, and defying physics. So MVHR system has been in around 4 years now, set the valves up last year. Unit is a Vortice HR200BP serving a small 79m2 bungalow, with all of the radial ducting in the loft under heaps of insulation. The inlet and exhaust ducts are preformed polystyrene type with a small amount of flexible ducting where needed, so as to create as little pressure drop as possible, and there is also a Blauberg Cleanbox 125 on the inlet, with G4, H16 and Carbon filtration in there. Couple of years back i bought some cheap temperature sensors off amazon just out of curiousity, as although the unit has its own temperature readings, they don’t include the temperature going back into the property, only extract, inlet and exhaust. Now I’m sure for a long time everything seemed feasible temperature wise, the extract was around the temperature of the bungalow, and the supply was slightly lower as you’d expect, some small losses. Now it’s constantly higher than the extract, which is obviously not possible, there is no magic heater or anything in the ducting. You’re probably thinking, just cheap sensors that aren’t reading right, i thought so too, so i swapped the supply and extract ones round and the ‘bad’ reading followed (and yes I relocated them on the wall correctly too! lol). Yesterday I had the unit all apart and checked everything, cleaned the G3 filter which is has on its extract side, and washed the heat exchanger out (though to be honest, aside from dust on the filter, it all looks like brand new in there), and it this point i moved the sensor which I had on the intake, to the exhaust just to see what temperature it showed compared with the units own sensors, and I was surprised to see it showing 17C, with an outside temp of 9C currently. Now the units own sensors shows 14C as the exhaust temp, and the sensors are literally next to each other, but could just be the poor quality sensors again? My main concern is the fact the supply seems to be warmer than the extract?! The air coming out of the ceiling valves using an IR thermometer shows between 18.8 and 19.5C depending on how far the pipe run is, which seems feasible. Does this all look OK compared with your units? Thanks in advance!