ProDave Posted July 10, 2018 Share Posted July 10, 2018 Just now, newhome said: Yes but you probably ended up with a bargain eventually despite the time wasted. That new one would be way more that 455 I’m sure. List price about £2K I believe. 2 Link to comment Share on other sites More sharing options...
readiescards Posted July 11, 2018 Share Posted July 11, 2018 9 hours ago, ProDave said: And mine only £455 But I am now on No 2 which thankfully appears to work, unlike No 1 What failed? Link to comment Share on other sites More sharing options...
ProDave Posted July 11, 2018 Share Posted July 11, 2018 1 hour ago, readiescards said: What failed? It never worked to start with, in spite of being sold as new. Then when pushed (and they had to be pushed) they admitted it was an obsolete model and they could not support it, so they replaced it with a different make and model. 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted July 11, 2018 Share Posted July 11, 2018 Remember that when speccing an ASHP, you need to oversize them. Link to comment Share on other sites More sharing options...
newhome Posted July 11, 2018 Author Share Posted July 11, 2018 14 minutes ago, SteamyTea said: Remember that when speccing an ASHP, you need to oversize them. But only if you see it replacing the boiler surely? My intention was for an ASHP to ‘help’ not completely replace the boiler. I’m not sure the difference in cost between a smaller one and a larger one stacks up TBH and a larger one will cost more to run so if it’s oversized surely that’s wasteful? How do I find out how much energy they take to run? So for a 9kw one for example as that’s the one @readiescards has bought from the bay. Link to comment Share on other sites More sharing options...
newhome Posted July 11, 2018 Author Share Posted July 11, 2018 Interestingly a friend has just viewed a house and sent me the link this morning. It has an ASHP and an energy score of 83. I mentioned this and she ignored that and said that it was smaller than the last house they offered on and she wasn’t sure about the location so clearly an ASHP wasn’t worthy of a mention in her eyes lol. I might ask her directly if that is something that they would find attractive in a house or not. Is RHI transferable? Not that I’m thinking of an MSC install however, just curious. https://www.rightmove.co.uk/property-for-sale/property-73377239.html Link to comment Share on other sites More sharing options...
ProDave Posted July 11, 2018 Share Posted July 11, 2018 An EPC of C is nothing spectacular, our old house achieved that with oil fired heating. If our new house does not get an A I will be very disappointed. I do however generally agree it is important to get the fixed things right, like location plot size etc, everything else you can change so I personally would choose the right location with the wrong heating system in favour of the perfect house in the wrong place. Link to comment Share on other sites More sharing options...
newhome Posted July 11, 2018 Author Share Posted July 11, 2018 3 minutes ago, ProDave said: An EPC of C is nothing spectacular, our old house achieved that with oil fired heating. If our new house does not get an A I will be very disappointed. I have no idea what my house is TBH. I've never been asked for it. Link to comment Share on other sites More sharing options...
SteamyTea Posted July 11, 2018 Share Posted July 11, 2018 (edited) 3 hours ago, newhome said: But only if you see it replacing the boiler surely? That does complicate it a bit. With an ASHP you have 3 temperatures to consider. The temperature you want your house at, which is affected by such things as insulation levels, airtightness, solar gain, wind losses etc. External air temperature, this affects the overall performance of the ASHP and gets more complicated when the affects of humidity are taken into account. The delivery temperature, this is just what temperature you want the heat pump side of the ASHP to output. Too high and the advantage of any heat pump is quickly lost. This is related to to the type of refrigerant gas used (more later). 3 hours ago, newhome said: How do I find out how much energy they take to run? See above, you need to know the coefficient of performance at different temperature and RH levels for each output temperature. It is why an ASHP needs to be oversized. This is not a fault, it is just the way physics works. You can think of it as similar to the way that fossil fuels are made. Each year that organic matter grows to get laid down in the correct place on the earth for form fossil fuels, there is a variance caused by different weather. Some years more gets laid than others (bit like my love life). The end product, say natural gas, is just the store, same as a thermal store, in a way. 1 hour ago, newhome said: 2 hours ago, ProDave said: An EPC of C is nothing spectacular, our old house achieved that with oil fired heating. If our new house does not get an A I will be very disappointed. I have no idea what my house is TBH. I've never been asked for it. Find out, or work it out, otherwise you are just guessing and can never make an informed decision. I suggested that the forum could have a calculator, but apparently it is 'too hard' to do. So we shall just keep answering the same question with the same incomplete answer. Or get a copy of @JSHarris's spreadsheet. Detailed weather data is available here: http://data.ceda.ac.uk/badc/ukcp09/data/gridded-land-obs/gridded-land-obs-daily/timeseries/maximum-temperature/ http://data.ceda.ac.uk/badc/ukcp09/data/gridded-land-obs/gridded-land-obs-daily/timeseries/minimum-temperature/ So no excuses for not knowing what the temperatures are. Edited July 11, 2018 by SteamyTea Link to comment Share on other sites More sharing options...
SteamyTea Posted July 11, 2018 Share Posted July 11, 2018 31 minutes ago, SteamyTea said: type of refrigerant gas used (more later Forgot this bit. The gasses currently used are being phased out and are almost certainly going to be replaced with CO2. CO2 is a much better gas as you can get delivery temperatures up to 90°C. Though how this affects the physical size of the units and the frosting issue I don't know yet. Link to comment Share on other sites More sharing options...
PeterW Posted July 11, 2018 Share Posted July 11, 2018 2 hours ago, SteamyTea said: Forgot this bit. The gasses currently used are being phased out and are almost certainly going to be replaced with CO2. CO2 is a much better gas as you can get delivery temperatures up to 90°C. Though how this affects the physical size of the units and the frosting issue I don't know yet. I run a Sanyo CO2 ASHP and the CoP at 50c is about 2.3. The big issue is getting anyone to touch it as the gas pressure is a magnitude larger than a normal ASHP and no-one has the specialist kit to service it. Sanyo dropped out of the market with these units as they were expensive and difficult to service so until they sort those two issues I expect we are stuck with standard refrigerants. Link to comment Share on other sites More sharing options...
SteamyTea Posted July 11, 2018 Share Posted July 11, 2018 Except we have been told to get rid of the old refrigerants. It is legislation not company policy. Link to comment Share on other sites More sharing options...
ProDave Posted July 11, 2018 Share Posted July 11, 2018 1 hour ago, SteamyTea said: Except we have been told to get rid of the old refrigerants. It is legislation not company policy. I started to hear about this when I encountered the problem with ASHP #1 that some of the refrigerants were being phased out and were in limited supply, hence expensive. It would be a shame if heat pump technology is restricted by such issues. One wonders what the future will be? Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 12, 2018 Share Posted July 12, 2018 20 hours ago, newhome said: I’m not sure the difference in cost between a smaller one and a larger one stacks up TBH and a larger one will cost more to run so if it’s oversized surely that’s wasteful? A larger unit won't cost more to run The energy required by the dwelling dictates the cost of whats produced / consumed. If it takes, for eg, 24kW of energy to heat your TS then it won't take more from a bigger ASHP, it'll just shorten the time taken to get there. It'll still have only used 24kW The benefit of the bigger unit would be quieter running as it would be using a smaller amount of its capacity, eg fan running slower etc. 1 Link to comment Share on other sites More sharing options...
newhome Posted July 12, 2018 Author Share Posted July 12, 2018 29 minutes ago, Nickfromwales said: it won't take more from a bigger ASHP, it'll just shorten the time taken to get there. It'll still have only used 24kW And it switches off / sleeps during down time a la the electric boiler, or does it continually check if the temp has dropped to see whether it needs to crank back into life again? Or is it called to start up via the heatmiser like the electric boiler is? Is it master or slave? Apologies for all numpty questions ? Link to comment Share on other sites More sharing options...
Stones Posted July 12, 2018 Share Posted July 12, 2018 @newhome we sold our last house which HD n exhaust air heat pump fitted without difficulty. Virtually every new build here in Orkney has an ASHP, be it A2A or A2W - doesn't seem to have slowed a fast paced market. You should be eligible for an interest free loan to install renewables (MCS install) the beauty of it is you use the RHI income to pay off the loan. Should be info on the EST (Scotland) website. 1 Link to comment Share on other sites More sharing options...
newhome Posted July 12, 2018 Author Share Posted July 12, 2018 1 minute ago, Stones said: You should be eligible for an interest free loan to install renewables (MCS install) the beauty of it is you use the RHI income to pay off the loan. Should be info on the EST (Scotland) website. Thanks. I’m led to believe that an MCS install would cost a crazy amount more than a cheap eBay purchase plus non MCS install, and that the RHI wouldn’t pay for the difference? Haven’t costed that yet however. Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 12, 2018 Share Posted July 12, 2018 In a high-energy consuming property the balance shifts towards MCS / RHI, so you would need to 'do the maths'. That may also be a good marketing legacy as the RHI is over 7 years ( domestic ) so may get handed over to the new owners. Just need to be sure your not still paying the loan off in 10 years time Link to comment Share on other sites More sharing options...
SteamyTea Posted July 12, 2018 Share Posted July 12, 2018 I think in your case you would be better off fitting PV, it would be cheaper and you will offset a fair slice of your usage as you can store a fair bit. Ditch that ST while you are at it. Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 12, 2018 Share Posted July 12, 2018 2 minutes ago, SteamyTea said: I think in your case you would be better off fitting PV, it would be cheaper and you will offset a fair slice of your usage as you can store a fair bit. Ditch that ST while you are at it. 5 year plan, Nick. Link to comment Share on other sites More sharing options...
SteamyTea Posted July 12, 2018 Share Posted July 12, 2018 If it is genuinely a 5 year plan, do nothing. Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 12, 2018 Share Posted July 12, 2018 1 minute ago, SteamyTea said: If it is genuinely a 5 year plan, do nothing. Thats one of the options yes Link to comment Share on other sites More sharing options...
newhome Posted July 12, 2018 Author Share Posted July 12, 2018 46 minutes ago, SteamyTea said: If it is genuinely a 5 year plan, do nothing. Alongside the 5 year plan was a desire to see whether an ASHP might help sell the house when the time comes as it can be challenging to sell in this area and with the house on all electric I have @Nickfromwales’ snickers bar comment as an image I can’t unsee . Hence the reason for this thread to question not just the pound for pound return on costs vs energy savings but also to explore whether the installation might make the house ‘less scary’ to potential buyers from a running costs perspective . I’m already in Council tax band G that’s not cheap. If it ever works again I have ST so PV might not be feasible in possibly the best orientation. Link to comment Share on other sites More sharing options...
SteamyTea Posted July 12, 2018 Share Posted July 12, 2018 Doing a quick calculation, if you install PV at £1000/kWp, at the 5 year mark the power will have cost you 22p/kWh, so about the same as E7 day rate (slightly less than mine). If you do go down the PV rout, you will ditch the ST anyway. Probably worth getting rid of now and save yourself approximately £120/year maintenance. Generally, any 'improvements' only add a little to the value of the house, any renewables will add nothing and, in some circumstances, detract from a house. If you said to someone that your RE systems gave you an income of £5000/year and paid for themselves in 2 seconds, that would make people suspicious, if you told them the opposite, they would not buy, tell them the truth and they will not understand it. We tend to get sucked in to all the RE technology and low running costs of a house, most people want a good school near by and some shops/pub. Sell a dream, not a reality. Infact you could market it to dog owners, that way it is one less near to me. Link to comment Share on other sites More sharing options...
newhome Posted July 12, 2018 Author Share Posted July 12, 2018 19 minutes ago, SteamyTea said: Doing a quick calculation, if you install PV at £1000/kWp, at the 5 year mark the power will have cost you 22p/kWh, so about the same as E7 day rate (slightly less than mine). My heating rate is 8p so pretty cheap. Standard rate is 15p but there is a 27p standing charge. 19 minutes ago, SteamyTea said: Sell a dream, not a reality. Infact you could market it to dog owners, that way it is one less near to me. Ha ha, that made me laugh! I might move to Cornwall mind and bring my dogs with me ??? Link to comment Share on other sites More sharing options...
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