billt

There are 2 point to point wi-fi links here using TP-Link CPE210s. One's to the front gate about 45M away for 2 IP cameras and ones to a pump house about 30M away.. Once setup they have been completely reliable for the 3 years they've been working.

We've recently bought a Segway Navimow i108. It uses GPS so no boundary wires and it has a camera to help with obstacle detection. So far it's looking good. It can manage our 4 grassy areas totaling 700sq.m. in time. To all intents and purposes it is silent. It uses the internet for rain warnings and it stops mowing if it rains - seems to be working reliably enough at the moment. It should be autonomous; you set up a schedule and it will look after itself and you can check on it remotely if you wish. Setting it up needs a bit of trial and error, for instance if you've set the boundary too near an edge it can deviate a bit and get itself stuck - as it did yesterday while we're away so won't resume mowing until Thursday!. But I think all that needs is a minor adjustment to the boundary. It space under the house wouldn't be suitable as both the mower in its charging dock and the RTK receiver need to have a good view of the sky. (That will be the case with any RTK mower.) It remains to be seen how reliable it is and how long the battery lasts.

And lots of survivorship bias. The ones that have survived are the expensive ones that are attractive enough for someone to spend money on to maintain. (I don't see any reason why a modern stick built house shouldn't last hundreds of years if it is maintained.)

https://diysolarforum.com/threads/house-burned-down.83098/ The chemistry might be relatively safe but they still store a lot of energy and there are other potential ignition sources. I would never install batteries in a loft.

Jeremy Harris is long gone but he used a Sunamp for water heating.

Why not unless you're in an area that experiences extreme cold? Ours are outside and haven't had a problem with cold yet. I have installed heaters but they haven't been needed yet and the amount of energy that they would use is fairly minimal. Another alternative is just to switch them off during the infrequent cold spells.

Although the heatpumpmonitor data is interesting, I wouldn't attach much significance to the rankings. When you look at the detail differences between the installations you'll find that system design is much more important than the heat pump model., as JohnMo said. There are also a lot of environmental and setup issues that change the rankings. A system in the south in a sheltered location is going to have a better CoP than a system in a colder and more exposed location, all other things being equal. The best performing systems are designed to operate with very low flow temperatures, some of the systems have low room temperatures and low hot water temperatures (or no hot water heating from the heat pump), those will also improve the performance. There are too few systems with too many variables to be able to come to any accurate conclusions. You should also note that although the highest performing systems are dominated by Vaillant Arotherm+ (the most common heat pump in the list), a Samsung Gen 6 model is performing extremely well. The Gallt-y-foel, Gwynedd system has a Cop of 4.7 which is better than most Vaillant systems and not significantly worse than the best performing systems at a CoP of 5.1. You're well into diminishing returns territory here.

I'd guess that it's in a recessed down lighter fitting. If it is they tend to get warm which seriously reduces the life expectancy of LED bulbs.

It was still the case last year when I had to return an inverter. Even worse I had to get an EROI number to get it returned to the UK as we'd left the EU then.

That rather depends on the nature of the building. In my case there were few occasions when only one room would call for heat, so short cycling wasn't particularly an issue. I was merely pointing out the reasons for having "smart" TRVs, not recommending them.

You can change the room temperature from outside the room. You can set an actual temperature, rather than a vague number. You get a reading of the actual room temperature (and humidity). You can link multiple radiators in one room together. When used in a suitable setup system the boiler will fire when any room is demanding heat, not just the room where the thermostat is situated. Of course, if you have a near passivhaus where all the rooms are the same temperature and that temperature doesn't change much it's moot. My Drayton Wiser system is now retired as the Wiser system isn't suited to heat pump control. Reverted to the old fashioned system of setting and balancing emitters to match each rooms heat loss with one temperature sensor in the living room. It works OK but has to run 24/7.

None of my SMA inverters need to connect to the internet. (I wouldn't buy them if they did.)

That rather depends on particular circumstances. Here solar is crap from the beginning of November to the middle of March. Dorset is pretty far south so will have better insolation than most of the country and individual location has a significant effect on energy availability. Over sizing is not really a solution; if there's low insolation levels you won't harvest much energy however large the array. Ours is over 14kW peak and still produces next to nothing in the winter. Yes, panels are cheap but most people have limited space to put them. We've used all the available roofs, and I'm going to ground mount an extra 3+kW, just because I can; it won't make a meaningful addition to the energy produced in winter.

Lynne got caught with this. She lost 2 years of state pension which she could reasonably have expected to receive, so something like £10-12,000 in total. That's a significant amount of money. As far as I can remember she was not told about the change form an official (government) source. We knew it was coming because we took a serious interest in pension planning and saw news reports about it. The main cause for complaint is the lack of information (no doubt that was deliberate) and the relatively short notice given; too short to make serious plans to replace the missing money.

Sorry but I don't see what is piss poor about that report. A typical retrofit to a reasonable standard is quite likely to have a sticker price of £10,000+ before grant. Some companies are offering a £500 install after the grant. The reporting seems accurate to me as far as it goes. I've retrofitted an ASHP; it cost me a great deal more than £10,000 in parts alone. It's a journalistic story not an in depth analysis of domestic heat pumps and is accurate as far as it goes. Why whinge about journalist doing what journalists do? Anyone more seriously interested isn't going to rely on a space filling story like that.

And the following paragraph says: "But some energy companies are offering heat pumps as low as £500 with the government grant." So you can't fairly say that that is piss poor reporting. It is entirely reasonable to say that the cost of a retro fit heat pump installation is likely to be £10,000 more than a gas boiler replacement before the £7,500 BUS grant.

Another vote for put it in the middle. What's the advantage of "freeing up the worktop"? You look to have a similar length on the right hand corner and you've got a big island.

The dangers of asbestos have been known for a long time. The first medical paper was published in 1924 in the BMJ and there were suspicions well before then. That paper dealt with fibrosis of the lung and TB. Suspicions of a link to cancer started in the 1930s and were confirmed in 1955 by Richard Doll. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1742940/ My father had H&S responsibilities in an aluminium recycling company and he had to consider the danger of asbestos in the early70s. If we had a no fault compensation system then suing wouldn't be necessary, unfortunately we don't, so that's the course you may have to take in order to get compensation for something caused by others inaction. I agree that the dangers of asbestos to the general public are overblown, like many other issues.

The room remote isn't supplied with the heat pump, but it's not that expensive. https://midsummerwholesale.co.uk/buy/samsung-heat-pumps/Remote-Temperature-Sensor-MRW-TA I suspect that the spares you have are intended to control a mixing valve, if they have the right characteristics they'll work but they aren't pretty and I doubt that they are the same as the remote temperature sensor. The remote room temp sensor plugs into a connector marked 'ROOM' on the MIM controller board. You also need to enable it from the remote controller. I think its FSV 2093, but I'm not sure.

Exactly. Measure the leaving water temperature, the return water temperature and the flow rate and you can work out the heat that the heat pump is producing. To raise 1m3 of water by 5C (typical rates for a small heat pump) needs 5.8kWh. I'm not sure that the CoP provided by the internal Vaillant meters is accurate, they seem to sometimes generate very optimistic readings, but 600% with a low flow temperature isn't impossible. My Samsung can get over 5.5 at times, and that isn't as good as the Arotherm plus.

If there is a Mitsubishi integration I would expect that to be easier to set up than Samsung. Apparently there is a SmartThings add on which has been made to work with Samsung heat pumps. As it's Home Assistant I guess it won't be easy. In my (small) experience anything out of the ordinary is a pain to set up.

It's the number of days below 5C that matters and here we get about 50 of those a year, about 25% of the heating season. That's going to significantly affect the SCoP. And of course manufacturers figures for SCoP are about as useful as MPG figures. The number of variables in any particular installation is huge meaning that the variables used in the makers calculations are highly unlikely to be reproduced in any given system. In my case I don't think that the installation can be improved in any meaningful way. It's designed with a flow temperature of 35C at OAT of -3C, it's completely open loop with a large water content, no buffer and uses WC with room temperature add on.

CoP at 35 LWT 2C outside Arotherm plus 7kW 4.3 - Samsung 8kW 2.98 (Samsung 31% worse) at -2C outside Arotherm 3.8 - samsung 2.67 (Samsung 30% worse) At 7C outside Arotherm 4.9 - Samsung 4.71 so not much difference. At 16:00 today the outside temp here dropped below 4C, eventually to 1.5C. The CoP over that period was 2.9. The previous day it was 4.8. That's a significant performance drop off. We've had quite a few days so far this winter with temperatures below 5C and virtually 100% RH, the combination of poor low temp performance and frequent defrosts is pretty dramatic at the times when you need heating most.

You can buy and add on for the Samsung (https://midsummerwholesale.co.uk/buy/samsung-heat-pumps/samsung-ehs-wifi-controller-kit-mim-h04en ) which uses a SmartThings app. It interfaces with Alexa and Google Assistant apparently so should be able to talk to HA. It's a pretty simplistic app, but lets you turn it on or off and change the temperature in 1 degree C steps. 8kW sounds a little on the large size for a fairly small well insulated house. I have an 8kW Samsung and it just about copes with about 170 square meters of heated space but mediocre insulation. It's slightly undersized but has been performing OK so far. If I knew then what I know now i wouldn't use an R32 ASHP but an R290 want, specifically the Vaillant Arotherm plus. They perform much better at less than 5C outside temperature than R32 heat pumps. The 5kW Arotherm shoulc be more than enough for your house, but you need to get the heat loss assessed properly.

That is rather dependent on the house design. Here we have 12 heated spaces. Doing that with A2A would not be simple. A2A is arguably less comfortable than radiator provided heat and they definitely make noise which may or may not be irritating. I've installed an A2A unit for one room which has 3 and a bit external walls and no insulation, but it would not be sensible to use A2A in the rest of the house.