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SteamyTea

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Everything posted by SteamyTea

  1. SteamyTea
    I am sure with a bit of thought and planning, brick or stone slip panels could be made in a factory, transported to site, craned into place and fixed easily. No good for a small builder as they would hate paying for a crane and will convince themselves that working in mud and rain they are 'doing the job cheaper'.
  2. SteamyTea
    My new rate is now 20p/kWh I think. EDF has pushed the price up 8% on average, but for my usage (sub 4,000 kWh/year), they are as competitive as anyone. Just as an example, if I go away for a few days and the cylinder cools to about 30°C, it only takes half and hour with the top immersion (3kW) to heat up a baths worth. So if you set the thermostats right, and someone does take a very long shower, there will almost be enough put back in for the next one.
  3. SteamyTea
    Basically what I did. 150mm of insulation and a 3 kW heater probably only needs 4mm2 cable, and that is probably what you would use anyway to reduce voltage drop.
  4. SteamyTea
    I think any DC route is going to be troublesome. An extreme example would be the creation of hydrogen and oxygen in the cylinder. I know Scotland wants to join the space race, by Cornwall is much better suited to it. (https://www.newscientist.com/article/dn25897-spaceport-uk-locations-for-launch-sites-unveiled/) One has to be careful when designing a system not to get carried away. We have gone from about a £1000 DIY system (my idea) To a £2000 plus system (Nick's idea) To a £4000 plus system (Terry's idea) (all figures are bad estimates to make me look good )
  5. SteamyTea
    The immersion is not a problem, just needs uprated wiring to it. Easy to check: http://myelectrical.com/tools/cable-sizing-calculator As an example
  6. SteamyTea
    Out of context to your last comment, but worth remembering just how cheap E7 is really. Even if it goes up 25%, it will still only be 10p/kWh for a cheap to install and maintain system. So if you need 10 kWh for all the DHW (including standing losses), it would still only be £1/day. Sometimes the law of diminishing returns comes into play.
  7. SteamyTea
    May have to set up a thread in Koffins Korner about this. I just get the feeling that there should be an easy and cheap way to monitor airflow.
  8. SteamyTea
    Just don't do it. I worked with this stuff 30 years ago and the risks where known about then. Have you thought of secondary insulation around a thermal store/DHW cylinder.
  9. SteamyTea
    How easy would it be to make a 'hot wire' mass flow meter to work with a RPI. They are only a warmed thermistor, a Wheatstone Bridge and a temperature sensor. So there would need to be an AD in there somewhere (or use an RC circuit for timing). Just thinking if they could be made cheap enough, one could be fitted in each duct and then adjust till all the numbers are right. Got to be better than running around the house all the time (and up in the loft).
  10. SteamyTea
    I think they work on 50% of the PV energy being exported. What annual yield did the EST calculator show for your system?
  11. SteamyTea
    Your more likely to get swamp gas than radon on your plot
  12. SteamyTea
    Eh Crofter, get Jeremy in as your first booking, he can do all the snagging Foot down, nothing, nothing, nothing, whoops. Why I got a 205 GTi
  13. SteamyTea
    Do UVC need a separate expansion vessels? If they still do (I have no idea), then the heat loss and leak problem is about the same as a vented cylinder I would have thought.
  14. SteamyTea
    I think there has been one recorded incident of someone being directly hit by a fragment of comet/meteorite in my lifetime (as opposed to secondary damage). So that is 1/(55 x 5bn) 3.6 x 10-12 chance. I suspect that lead poisoning from a soldered joint is a lot higher. Car driving is a lot more dangerous, even on lead free fuel.
  15. SteamyTea
    Not sure about the acidity of the water down here, but my element is probably the original, so 30 years old this year. This is the inside of my ten year old and ten quid Tesco kettle (and it has a lot of use in my house).
  16. SteamyTea
    Nick Is there any reason, other than personal preference and cost, to just vent a UVC. That way you get the built in heat exchanger (only a coil of pipe after all) and you can then just plumb in as normal. I know you very much like UVC as it saves a bit of plumbing up to a tank, but that seems to be all it saves. I almost agree with you on the G3 inspection on rented places, which is why I disagree with you on a gas hob, just something else that needs inspecting and can go wrong (I can see a visitor not bothering to twist a valve to the on position and the husband pulling the installation apart to 'fix it'). A two 'ring' induction hob is probably all that is needed for a holiday cottage. Flick the switch on the wall and it is ready to go. Might be worth getting one of those pyrolytic ovens though. A clean oven says a lot (says you can't cook generally, or your staff need more training, says someone that has a dirty oven at home and a spotless one at work). This is an alternative for the shower, very cheap to fit, about as efficient as you can get, probably could be modified to work as an inline heater, and the user will not be able to say much when it fails.
  17. SteamyTea
    There is no reason why they should not work (never answer a question with a negative, but hey ho). As long as there is a good stable water supply they should perform as expected (not difficult physics). Would make the plumbing in a new build or major refurbishment easier too. Just for a laugh, and not having done a Silly Sunday Experiment for a while, I just filled up my 2 litre water jug from my kitchen tap, too 5 seconds, so 24 litres/minutes flow, took 6 seconds on the basin tap. So 20 lt/min flow there. So even allowing for some losses (friction, pressure and generally efficiency), I would think that a shower with a flow of 15 lt/min would be quite possible at my house. That is almost 50% greater than what I have (and I have no real complaints with the shower). Knowing that leads nicely into sizing a cylinder. I have 200lt of water at 50°C, which is probably closer to a mean of 40°C, but as Crofter will be running his at a minimum of 65°C, his mean would be closer to 50°C overall I would think (there are ways to reduce the temperature gradient to get a greater capacity from the same size cylinder). As a shower does not really need to be hotter than 40°C, 90% cold water would need to be added (almost 50/50 mix as it depends on mains temperature). This would give an equivalent of a 420 lt store of water for showering. At 15 lt/minute, that would give 28 minutes of showering (all these figures are a bit rough). Might not sound much, but that is before any extra energy is inputted, and working from a 200 lt cylinder (and about what my old lodger did before I educated her, with a stick). This might cause problems when on E7/10 only, but an extra 10 kWh of energy at day rate would be about £2/day. As I suspect the place will not be rented out at 50 quid a week, not really a real problem. Just let the secondary immersion heater deal with it via the thermostat (say set 10°C lower than the main E7 one).
  18. SteamyTea
    I just had a look too. Seems you can get then from about £300, so no real price difference. Be nice to see one in action.
  19. SteamyTea
    I did not even think about it ten years ago. I am not sure what they cost or how easy they are to fit. I did not want to do any major work to the party wall (casing in pipes) or pulling up flooring. When I did it, I think the total cost was less than £200 including the DPS, the DP RCD, pipe and fittings (sill have a load of the pipe left), new mixer tap with the shower attachment and pump. If I was building a new place, I may well do things differently, not sure. I like the simplicity of my system, and the reliability has been excellent. Without having ever seen, let alone tried a venturi system, I cannot really comment on them.
  20. SteamyTea
    The main problem is making sure there is enough space around the cylinder to add insulation. But that is a problem with all insulation. Just treat it as you would a house, insulate and make airtight. The other thing I have noticed about all the cylinders in all the houses I have had, the immersion heater has always been fitted at 90° to the opening. So basically, up against a wall. This makes adjusting the thermostat hard, and in this house it would be impossible to remove and replace the element without removing the cylinder first.
  21. SteamyTea
    Basically yes. But if you insulate it well, then the losses are reduced. They are probably small compared to the cylinder losses though. It is all do to with surface area and temperature differences after all.
  22. SteamyTea
    You will. and should, put a pump in for a shower. Gravity fed showers need a lot of head, and generally have increased flow, which kills your storage capacity. There is a noticeable difference between winter and summer with my shower temperature settings. My header tank is in the loft, which gets warmer in the summer, means I turn the leaver down a bit. I am not convinced that fitting the header tank inside the heated envelope would make a huge difference overall. With a rental place you will be running the cylinder at 65°C anyway (legislation for legionella), so just work with that. It is easy enough to work out the heat losses, and how to mitigate them (just add 200mm of celetex inside the airing cupboard, make a larger cupboard, and don't forget the base and the top). Make sure the wiring is correct too. I like to keep things simple when designing; a header tank, an vented cylinder, an immersion heater or two, simple controls (on or off) and a shower pump. Can't get much easier than that for a DIY project.
  23. SteamyTea
    No, that is the whole point. I have a very basic vented cylinder for the hot water. From that a hot pipe goes to the bathroom for the basin and the bath. The pump goes after the Tee to the basin and just pumps the hot water to the bath mixer tap. A secondary cold pipe had to be fitted from the header tank to the cold side of the pump (as the cold was originally mains pressure). It seemed odd at first to have a pump running when filling a bath, but I got used to that. I could have fitted a separate shower mixer, and if it was a new installation I would have, but this was a quick and cheap solution to not having a shower. In a soft water area like mine, there is no need to ever worry about plumbing. Scaling up just does not happen and I think that is one of the biggest problems with plumbing. Scale is akin to having a huge variable resistor fitted to your electricity supply, and ever day you turn it down a notch. If you have hard water, you have to fit a water softener. No argument.
  24. SteamyTea
    My shower delivers at 11 lt/min. If I had plumbed it in separately from the bath, and fitted a different (larger) shower head, it would probably deliver 20 lt/min, as that is what is pumped out of the bath taps. I don't have a thermostatic mixer, just a cheap mixer tap with a shower fitting. Something like this: http://www.screwfix.com/p/swirl-deck-mounted-bath-shower-mixer-tap/41966 It does not give me any trouble at all. The pump is similar to this: http://www.screwfix.com/p/stuart-turner-showermate-eco-s-positive-head-shower-pump-1-5bar/58337 I fitted it over ten years ago and have not done a thing to it. Was a easy half days work to install, including running the cold feed from the header tank and fitting the RCD and DPS outside the wet area.
  25. SteamyTea
    You can get a system now that will do it remotely via your phone. Would it be possible to fit a larger IWH supplying water hot enough for a shower and with a large enough flow. Then, using that same IWH, pipe of to the kitchen and ad another inline water heater to boost it up a bit further. I would seriously consider an E7/10 (or funny Scotch tariff) for DHW. The standing losses from an ordinary cylinder can easily be reduced by fitting secondary insulation. Not a hard job if you do it at the time of fitting (not that hard to retro fit either). Just seen your post Crofter. I fitted a small shower pump from Screwfix (the smallest they do) and I have a good shower. My system is a vented one and so far has not given any trouble at all. A Header tank and 200 lt cylinder, a hot pipe off it to the bathroom, tee'd off to the basin and the bath/shower, an inline pump under the bath (does hot and cold), to the bath taps and the shower. Easy and simple.
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