pdf27

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  1. A guy I used to know now lives in Vietnam, teaching the locals English with a strong West Country accent. I really want to meet some of his pupils one day!
  2. Things aren't quite so clear cut. If you're exporting to the grid, you are meaning that fuel isn't being burned as a result - importing means that additional fuel is being burned. 90% of the time the difference comes out in the wash - it's gas plant with a reasonably fixed efficiency which is being turned up and down, so using the electrons provided by your own PV doesn't make much of a difference. What does have an effect is if a particularly dirty fuel (i.e. coal) is on the grid - mostly in winter at the moment: Not the easiest graph to read, but it's pretty clear from the middle chart that coal is mostly on during the day. So that means at this time of year (when admittedly you won't get much from your solar) you're better off running it at night. Octopus agile pricing is actually a pretty good proxy for how clean energy is - burning fuel costs money, so if it's cheap it's probably green too. I'd just run it whenever need to in order to stay comfortable, and not worry about it.
  3. It's worth noting that the Tesla system is claiming to compete with US residential solar systems on price - but those are hideously expensive compared to the UK. The US also mostly uses asphalt shingles for roofing, which have a pretty short life so their comparisons often include the cost of replacing those several times. I tried to do the maths on it a while back, but it was horribly expensive compared to something like the GSE system with conventional panels.
  4. Agreed with Ferdinand, I think you're going to need legal advice here and I also suspect that you would probably spend more on legal fees than you would ever recover. Looks like you've got (2) covered but fail with (1) and (3). If the church were to pay you your costs they'd get (1) and (2) but not (3). You **might** be able to claim against the church, but that will depend on exactly what they told you and how - and getting legal with them might not be the most effective route. I think your best bet would be to talk to them and point out that your report saved them a lot of money, and ask them to share the cost of the emptying, inspection and report - that would with luck get you 2/3 of your costs back without having to get legal and upsetting everyone. It's probably also more than you'd end up with going down the legal route.
  5. It's worth remembering that the rate of heat transfer is very strongly linked to the temperature difference between room and floor (the radiative component goes with the fourth power of temperature). If you can run the water relatively cool and still get enough heating on the cold side, you aren't likely to notice the additional heating on the warm side with a single zone.
  6. Another issue is applying the correct boiler efficiency - because a thermal store heats the water indirectly (you don't store the water you're using, but rather it's heated by a heat exchanger within the tank) then you typically need to store the water at a higher temperature. Since boiler efficiency is a function of flue gas temperature (itself a function of return temperature), running a cylinder hot will reduce the boiler efficiency even before you account for the increased losses of it being hotter.
  7. This sounds seriously shady to me - as in, I wouldn't be confident that this buyer would ever get the mortgage they've applied for. Have they got a seriously good reason for applying for a mortgage from an Indian bank on a UK property?
  8. Sadly the evidence of the past year suggests that they won't get any better, they'll just borrow a vast amount of money and funnel as much as possible of it to their mates, irrespective of if they know anything about the subject in question.
  9. The Bronze-Age population of the UK was at most 100,000 - and even that had a major impact on the environment. A handful of people living like that is OK, but too many of them would cause big problems for the rest of us.
  10. pdf27

    2nd Dec ASHP - or not

    "Not very eco-friendly" is really difficult to justify. If you look at something like Gridwatch, there is virtually no coal fired electricity left on the grid. That means any extra load on the grid is generated from gas at ~55% efficiency - so any heat pump with a COP of better than about 2 will be significantly cleaner than mains gas (i.e. it's cleaner to burn gas in a power station than at home). Drax is about 40% efficient, so if you're better than a COP of about 2.5 you're cleaner burning biomass for electricity and then using the electricity in a heat pump. A lot of people on here have noted that a professional/MCS install of a heat pump adds a LOT to the price - and certainly monobloc heat pumps aren't difficult at all to install. Work out the cost numbers for yourself rather than believing they're what a magazine article tells you they are. Electricity is always going to be more expensive than anything else per unit, but if you're already on the electricity grid then that isn't a true picture - paying for the extra on your bill is all you have to do in cost and time terms. Oil, biomass, etc. are somewhat more demanding, gas has an extra standing charge, etc.
  11. Shouldn't do - the meters sum across the three phases and are supposed to be able to cope with export on some phases and import on others. You're never going to perfectly balance across all three phases anyway.
  12. Assuming that the flow rate and heat capacity of the water is constant, then temperature difference is a pretty good proxy for heating power, and then multiplied by time gives energy. Essentially it sets the size of the lumps in which the heat pump delivers energy - the idea is probably to reduce short-cycling without affecting comfort too much, and changing the parameter allows you to vary whether you prioritise avoiding short-cycling (big number) or achieving a very stable temperature (small number). Basically you want the biggest number where you don't notice any issues with comfort.
  13. Burning a Range Rover every month is apt to get expensive though!
  14. This scheme? https://ecab.planningportal.co.uk/uploads/1app/guidance/guidance_note-larger_home_extension.pdf An adjoining neighbour has objected, so you need prior approval. Fair enough. However, that only means the planners need to determine that the effect on adjacent properties is not "acceptable" to refuse you. What reasons did they give for this?
  15. Does it actually need hot water, or is it just a case of "would be nice"? If it's a bit optional then an all-in-one solar system is probably a good bet. I'm assuming that most scout camping is in reasonable weather, and it'll be shut down in winter - this would be a doddle to drain down and cover over for the winter. Edit: clearer image