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SteamyTea

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Everything posted by SteamyTea

  1. Your house is a similar size to @joe90s, he fitted his own I think. And yes to UFH if you have a decent amount of insulation under it.
  2. I laid my own, was not that slow, or hard to do. An angle grinder with a sanding disk is your friend.
  3. Not got zoom, but I know it goes on mute quite often. I shared a flat with a Kiwi Sax player. I had to move out. Though he did do a good version of Bowie/Mercury Under Pressure.
  4. My house used about 85% on the cheap rate. The price difference is 12p/kWh. So in my usual usage of about 11 kWh/day, upping that by 13% would save me a whopping 13p/day. If all my power came in free, then I would save £1.3/day, £465/year. Sometimes it pays to use more.
  5. All comes down to the nature of heating and cooling. With a cooling curve.
  6. The main one is power, it is no good having a really good CoP but only delivering 500W. One of the problems with heat pumps is that people forget what they do, and how they do it. Then get bogged down in details like thermal stores, flow rates different temperatures for different jobs. Main thing to remember is that space heating and DHW are done at different temperatures, different times and different flow rates. The 3Ds.
  7. Well you have a lot more than 1kg of air to get rid of, but that also means it does not get so hot. But if you do fit a very large fan, and grow mullets, you can make so old school video. The only people that say they don't understand today's music, are the ones that don't get it. I don't get it.
  8. Yes, they were only a little disaster. My house has 200mm of mineral wool insulation and good airtightness. It was a pre-production model constructed for testing. The plastering is crap though.
  9. It is all to do with the low specific heat capacity of air. Air is around 1 kJ/kg.K. In more understandable units, that is 0.00027777777777778 kWh/kg.°C So if you have a system that is drawing 500W (a small fan heater) and it runs for 1 hour, that is 0.5 kWh or 1800 kJ. Now a kg of air has a volume of around 0.83 m3. So to keep the air at the same temperature (assuming no other losses), you have to shift that air away at a rate of 1500 m3/hour. It is more usual to use the litre/second as a unit, so that is 417 litres/second. Quite a lot.
  10. It is all to do with the condensation risk. The risks are different for different climate regimes. I think this caused a few problems when the UK built TF in the 1980s. Since then a lot has been learnt (my place is a late 80's TF and not a problem here as far as I know).
  11. This is really a failure of the auctioning system we currently use, with better management, it should become a thing of the past.
  12. Can you put all the electronic stuff in a ventilated area, then pump the excess heat out. Or go capella. Being someone that 'speaks' BSL, hours of fun can be had singing in a public library.
  13. If there are 5 if you in there, and you all generate about 300W, then that is the same as a fan heater going. Have you thought of playing at a slower tempo.
  14. Mould maybe. If the affected area is mainly in shadow, has poor airflow and little temperature rise above ambient, moulds can easily grow. They don't have to be just on the surface either, they can survive in the substrate.
  15. Different climate. Very cold and dry winters, very hot, and sometimes humid summers. Not much spring or autumn.
  16. Temperature is not heat (heat is the old word for energy). The reason you can adjust the temperature is that there is sweet spot for effective heating, or reheating, the cooler returning water after it has been though the radiators. This sweet spot is generally after half the energy has been removed. So say your water leaves the boiler at 80°C and returns at 60°C, then the radiators, on average, should have a temperature of 70°C. [to get the ° sign, hold the Alt key down and then put in the number 248] So my estimate of 8kW sizing was a bit low, this is the problem of working with averages, rather than actual data. I also probably under estimated the DHW needed, I forgot you had a large 5 bed house. When using a heat pump, it is more normal to have them running constantly, or as close to that as possible. This is generally not how a thermal boiler is set up. They tend to put is a lump of energy, then none, then another lump. This is partly why they are not that efficient at converting chemical energy to thermal energy. The stated efficiency of a boiler is the maximum it can achieve in ideal laboratory settings, real life knocks a few percent off that figure. So it seems your boiler is a bit oversized as it it set to the lowest temperature. I don't know if it is possible to downgrade your boiler to a lower output, some can be changed with smaller jets. That would reduce the fuel used. I do not have much against oil boilers, they are pretty good and the emissions are not as bad as people think. There is price volatility in the fuel costs which can be an issue as we have got used to relatively low heating oil prices over the last decade. Generally electricity prices are less volatile and new generation capacity from renewables are now the cheapest method to increase capacity. So that should suppress prices long term.
  17. That will be about 10.5 MWh (assuming boiler is 80% efficient). How water usage will be about 2.5 MWh a year. 7 kWh/day (for a bath and a shower a day). Ideally you want to heat water fairly quickly, say 3 hours. So 2.5 kW. So that leaves 8 MWh/year for space heating. Assuming you heat the house for 8 months of the year, that is 1MWh/month. As a rough average, that is 33 kWh/day. This is a power delivery of 1.4 kW. Now you hardly need the heating on between May and November, so that is probably really only serious heating for 6 months, with the greater heating needed in December, January and February. A bit of spare is needed for extreme conditions, so let us tripple the power delivery to 3.5 kW for space heating, plus the DHW of 2.5 kW. This gives you a rough size of 6 kW for a heat pump. Now it is normal to oversize a bit, somewhere between 15 and 30%. So somewhere around 8 kW is, from these rough estimates, is the size of heat pump needed. It is very tempting to install an ASHP that is only just large enough, as this is the way that traditional boilers a sized. Traditional boilers tend to work best when they are at maximum power, this is because they have less losses per power delivered. Heat Pumps are not like that, they tend to loose efficiency the closer they get to maximum power, and can even rely on an inbuilt electrical resistance heater. They also rely on the outside air being dry. This leads to a quirk where the CoP can be lower at a higher air temperature. This is because air above 0° C can be more humid, and at 4°C can have the largest amount of water in it (water has greatest density at 4°C). By over sizing an ASHP, there is a larger area of the heat exchanger (just a car like cooling radiator), This allows for a bit of frosting up while still allowing energy to be transferred (the energy is gained by a cold liquid expanding into the radiator and turning to a gas, and then being warmed by the outside air, some designs are different, the the theory is the same). If you look at your boiler, it should state how large it is. This may be in kW (kilowatts, not KW, killa wot or the big sin, killer Watts per hour) or BTUs, British Thermal Units. A BTU is an odd unit, but 1 kW is equal to 3412 BTU/hr (this is where the confusion of with power and energy come from I think). So if you can have a peak at it sometime and see if you can find a number, that would be useful.
  18. I rewrote the words to The Laughing Policeman once. Good luck with that.
  19. Removal of all the mess made mixing up mortar, broken blocks, etc.
  20. Put in some really powerful UV LEDs, that will kill all the germs. And like all boys in the shower, spending too long in there 'washing', will make you blind.
  21. I have nothing more to add.
  22. Should not be hard to do All the hardware and data is already in place, just need someone to organise it all.
  23. Without knowing what your heat losses are, you cannot possibly say that your ASHP is the correct size. So I suggest you ask the installer to show you the calculations, then you can work out if the system is designed, and working as it should. Or you can keep thinking that everything is 'just wrong'.
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