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TerryE

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TerryE last won the day on January 22

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  1. We just bulk-buy the salt block and have to remember to check the unit once a week or so and add another couple of blocks when needed.
  2. How often do you need to descale your kettle etc.? We considered our water "slightly hard". Your local water authority should publish a water hardness by geo location report, and ours was harder that I thought. We have a Harvey Salt Ion exchange softener on all water as Nick suggests. Absolutely no regrets, as we next get scale in our appliances, taps, shower screens, etc. Remember that if you have any thermostatic mixers on any of your potable lines then these can fur up and fail if your water is at all hard. As Nick says, anything other than ion-exchange is just snake-eyes.
  3. On this one, a few of us have gone down a dissenting route and have been successful at it. I did the overall design for my house myself and spent a lot of time on the 3D visualisation to make sure that the internals worked as a whole. I then used a decent local architect technician to draw up the set of plans for planning submission, and put the money that I would have spent of architects fees into our TF and passive foundation by subcontracting a decent custom build TF passive house specialist firm (in our case MBC, though there are a few to choose from). I did all of the design validation myself. To be fair, I had recently retired when we started the build, so I could invest the time in doing the research and getting on top of all the issues. I do disagree with Mike on "PH experience doesn't matter". If you are going to invest in an architect's services then he or she should be competent to do what you require: although passive house design is any more difficult than classic UK build, IMO, it is just very different. For example, it is really hard achieving passive class performance with conventional foundations + beam and block floor + block and brick leaf walls. We used a warm slab (that is a floating reinforce slab with UFH in-slab on a structural EPS bed + twinwall TF with blown cellulosic filler: this technique achieves passive-class almost by design. Anyway have a browse of some of the blogs, and do your research. 😊
  4. You need an electrian, though TBH is you own a multimeter, then this is probably something that you could buzz out yourself -- so lonf as you understand and are confortable with all of the 240V safe working pactices.
  5. I would say one benefit. I think that the other major plus is that the plumbing is 1-1 point-to-point, so no hidden joins or branches. The "Clapham Junction" of runs in the ceiling running into manifolds is also worth planning out and routing properly to avoid getting into a rats' nest of pipework. Certainly in a new build pulling the Hep20 was a doddle: you just had to be careful to keep the pipe clear of any sharp edges such as EcoJoist webs. We used 15mm throughout for simplicity, but in retrospect we should done what Nick suggests and that is to plum the hot runs in 10mm. Oh dear, we loose an extra ½l of water and wait an extra 5-10 sec for the hot to run hot. 🤣 Picking up @Russdl's point, I went round carefully trimming all the flow rates before the final inspection, but our inspector never even bothered checking. However the only two that we changed back were kitchen and utility sink mixers. TBH, we doc't find the low flow rates on the ensuite basins an issue. If anything it's an advantage: before I fitted the regulators, if you turns the tap on full, then the flow was so strong, that it would shoot out of the sink and soak evertything.
  6. Broadly the situation on non-heating days is that the indirect heat sources (solar gain, warm bodies, waste heat from misc electricals) generally exceeds the fabric heat losses, so the house will steadily heat above your desired setpoint. Having your MVHR bypass its heat exchanger so the outgoing house air is swapped for unheated external air is one mechanism for dumping excess heat. However, you don't want to do this if the external air is warmer than the internal setpoint as you would want the heat exchanger running to keep heat out -- hence the min / max setpoints on the MVHR. You can do the sums on flow volumes + temp delta for your system to work out the kWh equivalent effects. Or you can set them by experimentation, but there is no standard "right" values -- these will depend on the characteristics of your house. My Ventaxia has a set of zero-volt contacts which can be used by a home automation system to fine tune all of this strategy, and I did initially plan to do this, but in the end we adopted my wife's strategy: we just open the odd window when needed. (We live in the country so the air quality is good, so long as the farmers aren't muck spreading. 🤣) However, we do exploit the fact that our 3 storey house is a sun trap on the principle SE aspect and the rear NW stays cool until mid-afternoon, so we crack a rear window in the morning and (if needed) a front one in late afternoon; this plus the roof light at the top of the hallway gives a very effective heat pipe to dump excess heat. I know that some members would regard opening windows in a house with MVHR as heresy, but as we don't have special needs (e.g. asthma suffers), we don't see why not when we want to dump heat.
  7. According to regs, compression joints in slab have to be accessible. No need for soldered joints once tested to be accessible. They fail because of cold spots / contamination preventing solder wetting / flow and so (typically) the flux residue is acting as a temporary seal that will ultimately fail. Ring fill have already got a 360° wet on the joint. So long as the pipe is clean and fluxed, then this will also wet forming a permanent seal. Same applies for elbows bringing pipe up from slab level. As Nick says, you can always pressure test before you pour concrete.
  8. I know the professionals like Nick make it look easy, but just about anyone who is modestly handy can do this So if you aren't familiar with soldering, then just buy 28mm ring-fills. You can dry fit and cut the pipe to length, then joint the pieces conveniently positioned out-of-place. Look at some YouTube demos of soldering ring fill joints. So long as everything has been cleaned to virgin bright copper and fluxed, and the area is clear of contacts / cold spots then you can heat the pipe uniformly and let the heat flow into the joint. Once the ring of solder wicks out under heat completely around the ring, then you know that the joint is sound. Clean. Ditto any end 90 elbows that are in-slab And remember that any piping in-slab must be decently lagged both for thermal reasons and to ensure that the concrete does not come into contact with the copper.
  9. I use a Sonoff Power-usage plug that I can control with my Home Automation system, but you can also get Android timer apps and they are also programmable with Google Home if you are happy letting Uncle Google control your devices.
  10. You can take smooth changes to the going (we have them on our staircases which have smooth 90° turns), but even the smallest variation in rise is a real trip hazard:
  11. Mortar has almost zero tensile strength. For more precise removal, use the SDS to drill a couple of holes side-by-side in the mortar course you want to yield, and bang a 25mm chisel in; a few sideways taps will loosen the brick. For rough removal a sharp bang with 3 kg sledge hammer works wonders though you will lose some bricks, so if you want to reuse them just work steadily breaking the mortar courses. What size digger needs to go through; just once or daily? I'd leave the brickwork to the RH side of the window alone if possible and remove the house side. If you do go the right try to keep 2-3 bricks intact on the turn, otherwise you could loose the end wall.
  12. This was my original intention. However as the convective radiator has to heat the air first of all, and then the air heats the structure to buffer the energy for later. It doesn't seem to work as well as directly heating an insulated slab. If we pumped in more heat the air temp would get too high and there'd be complaints! As it is we run the rad slightly colder during the night and turn it on again at about 6pm on a low setting to keep everything toasty. I agree that heating a lump of concrete in the 10s of tonnes does act as a good smoothing buffer, but I did play around with a simple thermal model to investigate the characteristics of the house dynamic. Do you have a digital spot thermometer? You can get them for under £20 now; borrowing one is even cheaper. Probably not wonderful in terms of absolute accuracy but good within ½°C or so relative. What is your total daily electricity use in winter? Let's just use 35 kWh as a strawman. You can really just about ignore the split between DHW, rad, other use because thanks to entropy every kWh you use (excepting perhaps HW that goes down the plughole) ends up as heat in the environment. And that heat is slowly lost externally through MVHR losses, radiation through fenestration, and radiation through other external facing surfaces. Let plug in some rough numbers, but you can do the exact ones. If 50% of the heat is lost through surfaces and you've say 400 m2 external surface, that's about 3½W per m2, so your external walls will be roughly ½°C cooler than the average air temperature. In other words 2 shades of bugger all. Try checking external and internal surfaces with a spot thermometer. I did. The worst I found in our house was along the edge of the reveals where the plasterwork meets the window frames which was maybe 3°C colder than room temp. Basically everything else was within a degree or so of the same temp. The lag transferring heat from airspace to surfaces isn't that great. Though local overheating can arise if you put the rad in a room and shut the door. That is why I suggest that you invest in a second rad, and as Nick suggests more child-safe digital timers. (Masking tape over controls to denote "do not touch" and whatever your favourite admonishment techniques should be effective with tinies.) A good location for the rad is a hallway, and leave some adjacent doors open. The MVHR can help circulate the heat throughout the house as well.
  13. @Iceverge, I would get too upset about the delta. As you say, there are a lot of reasons for the variation as we've also found, e.g. you find that you prefer a warmer environment than your PHPP set points; laxness about sealing the house on ingress/exit, ... Like us, you now have a baseline, and you really need to base any potential changes in terms of RoI and any assessment of increased benefit vs hassle and stress of change, and we've found that this sets a high barrier to change. However, a couple of thoughts: What sort of time constant does your house have? E.g. ours loses about 1°C per day in deep winter if unheated. With this sort of house response you can shift heating times without noticeable effect: you need to put X kHr into the house per day, and it really doesn't matter when and where you do it. I don't know if you use a dual tariff, but when we did the calcs this saved use about 40% on our cost of electricity: heating, DHW heating, dishwasher and washing machine are all on cheap rate. We have a larger (~260m2 IIRC) house, and use a 3kW Willis + UFH for our primary heating, but I also have a 2kW oil-filled rad on our 1st floor landing in the winter that I run for a few hours overnight to top up the heat in the upper floors. You could just run your heater overnight (or add another if necessary). To keep your house near setpoint, you just need to top up the heat daily. It does really matter where or when. You could consider adding a split aircon unit in a hallway or living room (something like this sort of unit). There are lots of choices at around 12K BTU / 3kW for around 600€. This can easily dump a few kW into the house at a CoP of around 4. Don't put in a bedroom, because they still generate around 30 dbA at a medium setting which is audible and you will probably want to run it at night for cheap rate pricing. Jeremy Harris fitted one and did a topic on doing this (here). He used a pre-charged one that can be fitted without any specialist certifications. So long as you do and seal the through-wall duct and run the external SWG feed (the internal unit is powered from the external), and mount the units physically, then paying someone to wire it in should only be in the 100€s. If you are looking at Home Automation, then HomeAssistant can be used to schedule your rad timing and control most WiFi enabled aircon units.
  14. My wife and I are both retired. We like wandering around in comfort and in bare feet etc. When we visit our kids' homes, we really notice how cold it can get when you wander from room to room, and the heating is on say during a daytime window, but the temperature drops rapidly when the heating goes off. Slippers and thick jumpers are pretty much mandatory in the winter. In our house, the temperature drops by about 1° C per day if the heating is off in the winter.
  15. Sounds like a load of marketing bollocks to me. Overall any house acts as a system that can be characterised and controlled given enough measurement points and data. However, I doubt that any acts as a linear system, and do it is still extremely difficult to realise as characterised control system. Some example: Most houses leak like sieves, to prevailing wind speed and temperature has a tremendous impact on air-exchange related losses Solar gain and direct radiant losses are critically dependent on the area and orientation of fenestration. We've got a top grade passive-class house and our heating system uses two main inputs: (i) the forecast daily average temperature, and (ii) how much the average house (actually central hall) temperature has deviated from the target set point. This give us a pretty stable 24×7 house-wide temperature with a ~1 °C ripple (all of our heating is done overnight). IMO, anything like this would be impossible to achieve with a minimum BReg compliant house.
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