Post and beam Posted March 15 Share Posted March 15 4 minutes ago, Gary68 said: it works well at the -2C design temp it has to run 24/7 to keep the house at 21C but works right down to the -7C I may well have misunderstood something about this line? If your pump has to work 24/7 to keep you happy at -2, how does it work at -7 Link to comment Share on other sites More sharing options...
George Posted March 15 Share Posted March 15 5 minutes ago, Post and beam said: I may well have misunderstood something about this line? If your pump has to work 24/7 to keep you happy at -2, how does it work at -7 Presumably at -2C it wouldn't be running full power. They can modulate output as well as reducing running time. Link to comment Share on other sites More sharing options...
Gary68 Posted March 15 Share Posted March 15 (edited) It defrosts less at -7C so increased running time at higher flow temps Edited March 15 by Gary68 Link to comment Share on other sites More sharing options...
PhilT Posted March 15 Share Posted March 15 1 hour ago, mk1_man said: Maybe I am worrying too much, just need to clarify what the minimum output is for an 11.2 Ecodan so as not to be cycling all of the time. I wouldn't be at all concerned about that. I'm in a similar postion, having switched from a 22kW boiler to an 11.2kW R32 Ecodan which has turned out to be around 100% oversized! At the current mild temps the auto mode manages it pretty well so it doesn't cycle more often than once an hour. My COP so far this year is 4.1, better than data table specs on any given day, and that's for a microbore/radiator system with two pumps and a low loss header. There's an intersting view here on cycling https://www.shenlingglobal.com/blog/unlocking-efficiency-understanding-your-heat-pumps-three-operation-cycles/ "What Is the Ideal Frequency for Heat Pump Operation? The frequency at which a heat pump turns on and off depends on your specific home and heat pump setup. The cycle duration should be sufficient to heat or cool your home effectively without putting undue strain on the system. Typically, a cycle length of 10 to 20 minutes, followed by a shutdown, is considered normal. Ideally, your pump should complete two or three cycles per hour at most. Under normal conditions, your heat pump should not run continuously, except during extended periods of freezing weather when it needs to maintain the temperature" Link to comment Share on other sites More sharing options...
JamesPa Posted March 15 Share Posted March 15 (edited) 2 hours ago, mk1_man said: The heating also runs infrequently apart from the 04:00 - 08:00 start time each day. My rooms are between 20.5° & 22° I just can't get my head around the fact the mcs figures are saying that I need to input 8kW or so 24 x 7 I'm not surprised at all. As I have mentioned many times on this forum two 3hr surveys on my house have resulted in a recommendation of 16kW. I got to 10.5 kW using MCS assumptions and the correct fabric (surveyors ignored invisible fabric upgrades and double counted some losses). Actual measured is 7.5kW, which I can also get to if I assume 0.5ACH instead of 2-3. My typical consumption during the majority of the heating season is 4kW. If I were to follow the MCS 'experts' O would end up with cycling most of the heating season. Edited March 15 by JamesPa Link to comment Share on other sites More sharing options...
George Posted March 15 Share Posted March 15 I definitely ended up with an oversized ASHP. Works fine but obviously affects running costs. However as I have 100% RHI so I'm not too bothered but when that is up I may swap it out for a much smaller system and give the 16kW one to my parents. I found the MVHR made a decent difference as well. Link to comment Share on other sites More sharing options...
Dave Jones Posted March 15 Share Posted March 15 3 hours ago, JamesPa said: It's there in plain text. The Town and Country Planning (General Permitted Development) Order 2015 clause G1 ( which is the section dealing with heat pumps) https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14/crossheading/class-g-installation-or-alteration-etc-of-air-source-heat-pumps-on-domestic-premises/made says (my italics) G.1 Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards or equivalent standards. The MCS Planning Standards are defined in MCS 020 as follows: That very clearly includes that it shall be installed to MCS standards by an MCS contractor. There are no recognised equivalent standards and, it seems to me that to be equivalent, it would need to include something like clauses (a) and (b) not just clause (c). Thus MCS becomes compulsory to benefit from PD rights. The key is the definition of 'the MCS Planning Standards ' Not aware of any heatpumps that dont comply with MCS standards. Also says OR EQUIVILENT. And mentions nothing about MUST BE INSTALLED by an MCS contractor either. G.1 Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards or equivalent standards. Link to comment Share on other sites More sharing options...
JohnMo Posted March 15 Share Posted March 15 18 minutes ago, Dave Jones said: Not aware of any heatpumps that dont comply with MCS standards. Also says OR EQUIVILENT. And mentions nothing about MUST BE INSTALLED by an MCS contractor either. G.1 Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards or equivalent standards. I'm in the same boat as you. Equivalent really means nothing. Don't see why me following all the MCS guidelines isn't the equivalent of a MCS person doing it. My noise is easy, main road 150m away nearest house 400m away. The heat pump can do all heating and hot water without issue, even if I used MCS calculation and ignored MVHR. Link to comment Share on other sites More sharing options...
JamesPa Posted March 15 Share Posted March 15 (edited) 43 minutes ago, Dave Jones said: Not aware of any heatpumps that dont comply with MCS standards. Also says OR EQUIVILENT. And mentions nothing about MUST BE INSTALLED by an MCS contractor either. G.1 Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards or equivalent standards. It's there in black and white, it must comply with the 'MCS planning standards'. So the question becomes what are 'the MCS planning standards'. The definition of 'the MCS planning standards' (which appears in MCS 020) includes three things, the noise requirement, a requirement that it is installed to MCS standards and a requirement that it is installed by an MCS contractor. There is no recognised equivalent standard and to be equivalent it would have to cover all three things on the MCS standard. I can see no escape (I wish I could!). Of course, like anything to do with planning, it doesn't matter unless someone complains, but if they do your LPA would be within its rights to ask you to produce the MCS certificate to prove it's permitted development and if you can't you will have a battle on your hands which ultimately can only be resolved in court, very likely with MCS giving expert evidence against you to preserve their monopoly. Fancy that? I'm not defending it, it's an atrocious misuse of power, but neither can I find a get out that would be likely to stop a determined LPA taking enforcement action if it got your angry neighbour off their backs. As I say it doesn't matter if nobody complains because that's pretty much the only time LPAs take enforcement action. Edited March 15 by JamesPa 1 Link to comment Share on other sites More sharing options...
JamesPa Posted March 15 Share Posted March 15 21 minutes ago, JohnMo said: I'm in the same boat as you. Equivalent really means nothing. Don't see why me following all the MCS guidelines isn't the equivalent of a MCS person doing it. My noise is easy, main road 150m away nearest house 400m away. The heat pump can do all heating and hot water without issue, even if I used MCS calculation and ignored MVHR. You are fine then because nobody will complain unless you put it somewhere it's a blot on the landscape and paint it red to draw attention to it.. That doesn't mean it's lawful, but it does mean that it almost certainly won't be enforced in practice, just like any other minor planning transgression of which there are many. Link to comment Share on other sites More sharing options...
mk1_man Posted March 15 Share Posted March 15 Its a minefield out there. At the mo I am likely to follow my gut and purchase my own solution and that's likely to be a Vaillant Arotherm (7kW) or possibly the new Samsung R290 unit (8kW) instead of the 11 - 12kW units that are being quoted. Nobody appears to pay much attention to the fact that I have been a little anal with the air tightness measures and insulation to way past building reg standards and the fact that we have an mvhr installed and triple glazed Internorm passive standard windows and doors throughout. They just go by the fact that its a 1960's house .... heat loss on recent quote has come down to 7.8 from the 10.5 the other two mcs companies quoted but they are still insisting that I need to add another 3kw for hot water capacity and that I have to replace my cylinder even though it is a twin coil (solar) 250litre and reheats very quickly at the moment. Going my own route allows me to keep my gas boiler and use it to heat the water and as a backup to space heating via a couple of shut off valves. If I have my calcs wrong when its -2 etc I can simply revert to gas for the few days ! Link to comment Share on other sites More sharing options...
JamesPa Posted March 15 Share Posted March 15 12 minutes ago, mk1_man said: Its a minefield out there. At the mo I am likely to follow my gut and purchase my own solution and that's likely to be a Vaillant Arotherm (7kW) or possibly the new Samsung R290 unit (8kW) instead of the 11 - 12kW units that are being quoted. Nobody appears to pay much attention to the fact that I have been a little anal with the air tightness measures and insulation to way past building reg standards and the fact that we have an mvhr installed and triple glazed Internorm passive standard windows and doors throughout. They just go by the fact that its a 1960's house .... heat loss on recent quote has come down to 7.8 from the 10.5 the other two mcs companies quoted but they are still insisting that I need to add another 3kw for hot water capacity and that I have to replace my cylinder even though it is a twin coil (solar) 250litre and reheats very quickly at the moment. Going my own route allows me to keep my gas boiler and use it to heat the water and as a backup to space heating via a couple of shut off valves. If I have my calcs wrong when its -2 etc I can simply revert to gas for the few days ! Exactly my experience. The contractors 'play safe'. (Almost) nobody complains about central heating so long as the house isn't cold and they can have infinite hot water on demand, and the grant conditions further encourage the behaviour because of the rule that the ashp must be capable of serving 100%of the capacity. So designers are highly motivated to over estimate the size and then throw in a buffer tank to reduce the likelihood of short cycling, and possibly also insist on unnecessary upgrades to pipework. Thus we end up with a greater number of overenginnered over expensive systems than we need. In some cases these perform so badly because of the overengineering that people complain about heat pumps being expensive to run. Basically the system, combined with human behaviour (both on customer and supplier side), leads to the unsatisfactory outcomes many experience. Link to comment Share on other sites More sharing options...
JohnMo Posted March 15 Share Posted March 15 Possibly a good solution. Would keep your options open to makes and models, while R290 may give high temps nothing wrong with R32. I laid £1300 and some else just got a Daikin for £1200. Same Vaillant is circa £3500. Link to comment Share on other sites More sharing options...
HughF Posted March 15 Share Posted March 15 Nothing wrong with r410a either….. keeping our place warm and toasty this winter 1 Link to comment Share on other sites More sharing options...
Dave Jones Posted March 16 Share Posted March 16 18 hours ago, JamesPa said: It's there in black and white, it must comply with the 'MCS planning standards'. So the question becomes what are 'the MCS planning standards'. The definition of 'the MCS planning standards' (which appears in MCS 020) includes three things, the noise requirement, a requirement that it is installed to MCS standards and a requirement that it is installed by an MCS contractor. There is no recognised equivalent standard and to be equivalent it would have to cover all three things on the MCS standard. I can see no escape (I wish I could!). Of course, like anything to do with planning, it doesn't matter unless someone complains, but if they do your LPA would be within its rights to ask you to produce the MCS certificate to prove it's permitted development and if you can't you will have a battle on your hands which ultimately can only be resolved in court, very likely with MCS giving expert evidence against you to preserve their monopoly. Fancy that? I'm not defending it, it's an atrocious misuse of power, but neither can I find a get out that would be likely to stop a determined LPA taking enforcement action if it got your angry neighbour off their backs. As I say it doesn't matter if nobody complains because that's pretty much the only time LPAs take enforcement action. nope doesn't say that. Nowhere I could see 'must be installed be MCS etc' Clearly states MCS OR EQUIVILENT STANDARD. Would clearly be illegal if it was the case as it would break anti-competition laws. Cartels are illegal. Link to comment Share on other sites More sharing options...
joe90 Posted March 16 Share Posted March 16 I installed my own, i simply put it on the planning drawings, no questions asked. Link to comment Share on other sites More sharing options...
JoeBano Posted March 16 Share Posted March 16 I install my own, oversized unit 10kw I needed 6kw. Had to install a buffer as I couldn’t achieve minimum flow rate. It’s sat on my garage roof followed mcs guidelines for noise assessment. Ive asked my neighbour couple of times can he hear when he’s sat on his patio he’s happy with it. you can hear it when it’s does hot water for the first 5 minutes when it’s ramping up apart from that it’s pretty quiet. Grant aerona 10kw r410a cost me £600 and a 3 hour drive to Newcastle, it was 2 years old. 1 Link to comment Share on other sites More sharing options...
JamesPa Posted March 16 Share Posted March 16 (edited) 1 hour ago, Dave Jones said: nope doesn't say that. Nowhere I could see 'must be installed be MCS etc' Clearly states MCS OR EQUIVILENT STANDARD. Would clearly be illegal if it was the case as it would break anti-competition laws. Cartels are illegal. You need to read it properly to understand it properly. The law actually says 'the MCS planning standards or equivalent standards'. So first of all you have to ask what does the phrase 'the mcs planning standards' mean, ie what is the definition of this phrase? The phrase is not defined in the legislation but it is defined in mcs-020 where it expressly says 'the mcs planning standards are:' and then lists three things, namely that it must be installed by am mcs contractor, it must be installed to mcs standards, and it must meet a noise criterion. So that is the definition of the phrase 'the mcs planning standards'. This must be the case because its only in this text that the noise standard comes in. That leaves only 'or equivalent standards'. There is no 'recognised' equivalent standard. So, if it were challenged, you would be left arguing that your own installation is 'equivalent' to which the response would be 'prove it'. You would likely have an mcs bod standing in court as an expert witness, because the judge wouldn't have a scooby. Good luck! Of course people do it themselves, following (or not) the noise rules and of course they get away with it just like people get away with many planning transgressions. That doesn't make it legal and doesn't protect you if your neighbour complains and your lpa decide to take the matter up. At best they could make things very stressful for a couple of years, at worst they could require you to move or remove it. It's a risk like any unauthorised development. Edited March 16 by JamesPa Link to comment Share on other sites More sharing options...
PhilT Posted March 16 Share Posted March 16 1 hour ago, Dave Jones said: Nowhere I could see 'must be installed be MCS etc' MCS-020 section 3.1 (b) (page 15) https://mcscertified.com/wp-content/uploads/2021/10/MCS-020.pdf contravention enforcement probably unlikely unless a neighbour complains about noise or visuals Link to comment Share on other sites More sharing options...
JamesPa Posted March 16 Share Posted March 16 38 minutes ago, PhilT said: 2 hours ago, Dave Jones said: Nowhere I could see 'must be installed be MCS etc' MCS-020 section 3.1 (b) (page 15) https://mcscertified.com/wp-content/uploads/2021/10/MCS-020.pdf contravention enforcement probably unlikely unless a neighbour complains about noise or visuals Precisely, on both counts! Link to comment Share on other sites More sharing options...
JamesPa Posted March 16 Share Posted March 16 1 hour ago, joe90 said: I installed my own, i simply put it on the planning drawings, no questions asked. That seems to be the odd thing. If you are doing a larger development which happens to include an ashp in, the LPA it seems frequently doesn't inspect the ashp aspect in much detail, and thus passes it in circumstances where it may well not pass the ashp as a standalone development. Together with the restrictive PD rules it's madness. Link to comment Share on other sites More sharing options...
Dave Jones Posted March 16 Share Posted March 16 46 minutes ago, JamesPa said: Precisely, on both counts! not legislation, a private company document. Link to comment Share on other sites More sharing options...
JamesPa Posted March 16 Share Posted March 16 (edited) 1 hour ago, Dave Jones said: not legislation, a private company document. No, but it's referred to/called up very specifically in the legislation. Without this interpretation there is no noise standard called up at all, further confirmation that this is the interpretation. Edited March 16 by JamesPa Link to comment Share on other sites More sharing options...
Dave Jones Posted March 16 Share Posted March 16 49 minutes ago, JamesPa said: No, but it's referred to/called up very specifically in the legislation. Without this interpretation there is no noise standard called up at all, further confirmation that this is the interpretation. all that i can see is the hardware must be to MCS or EQUIVILENT spec. Nothing about a particular private company having to install it. so no to be clear, PD is not dependent on MCS at all. Link to comment Share on other sites More sharing options...
Dillsue Posted March 16 Share Posted March 16 10 minutes ago, Dave Jones said: so no to be clear, PD is not dependent on MCS at all. https://www.planningportal.co.uk/permission/common-projects/heat-pumps/planning-permission-air-source-heat-pump Unless you can find equivalent standards, then PD seems to be wholly dependant on MCS standards Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now