offthepiste

I know a company, well experienced in passivhaus and enerphit, that has been installing ASHPs in council properties (along with appropriate insulation, etc. measures.) They have taken great lengths to inform and try to educate the residents about how ASHP works and how to live with them. They have found that the vast majority of residents have ignored them with many switching off the ASHP and resorting to electric heaters .. and then complain about their heating bills. I know, having recently completed our retrofit, that ASHP and associated low operating temperatures take a little getting used to .. and have had to be patient with myself! It does take time to learn to live with ASHPs and configure them for a whole house (we have GF ufh and low temp jaga rads upstairs along with mvhr)

Re @ProDave comment regarding octopus offering ASHP. Whilst I absolutely support ASHP suspect the octopus initiative will automatically attract serious negative (gutter) press. I answered their online questionnaire knowing that it should not recommend ASHP without first having addressed insulation and airtightness issues we previously had in our victorian terraced house. The implication from the outcome of the questionnaire was that I was good to go in installing an ASHP without addressing the other - very expensive issues. octopus should seriously be upfront about these issues.

👍 @SteamyTea

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If anyone is interested in the Grohe unit, I have been reading various review - some regarding the Grohe App. I think from what I have read that the hardware is good, if not excellent. However, the main issue seems to be that it is pretty dumb - and primarily based on a daily water usage limit which seems to be the primary value for triggering it to say that there is a leak. There is also some measure of water pressure so am not sure how this affects its behaviour. Probably the biggest issue is regarding the Grohe App. The reviews on the Apple App Store are pretty damning. This is a shame as the Grohe portal is pretty informative. One big issue seems to be that the Grohe unit shuts down the mains triggered by a water softener going into regeneration mode. We have just had an east Midlands Eco Premier whole house system installed - so I have contacted East Midlands to see what & when regeneration is triggered. I am very keen to get the Grohe unit so want to understand its limitations and possible work arounds. My Options: 1. If I can accurately predict softener regeneration then I could use the Grohe sprinkler schedule cover this water usage. 2. If the Eco premier regenerates on a daily basis then I could include this usage into the daily limit. 3. I could switch off the Grohe Controller so that it does not shut off mains automatically and just notifies me. I could also invest in a couple of floor sensors to validate any warning. 4. Not install the Grohe! Re the Grohe App, I think their team probably needs a kick up their collective nether region. They could include more exception scheduling and possibly some machine learning (I am not a great fan of AI - being very much a determinist!). Cheers Wonder if @SteamyTea and @ProDavehave any view on this? They, among many others on this site, have views that I greatly respect. PS: Just had a reply from Grohe recommending installing Water Controller after the Water Softener unit ... why did I not think of that!

Has anyone got any experience, good or bad, regarding the "grohe water sense smart water guard" which can water leaks directly through mains flow and can switch oof supply, etc. I know that @lizzie mentioned one in 2019. Thank you in anticipation

Hi @Archer they are not fitted yet, will give you an update once they are fired up. The retrofit is being done as a turn key project by a main contractor. But wil try to get detail on dealing with Jaga. We are not using them in cooling mode as this will be handled by Zehder MVHR. cheers

I would not want to have a battery located in doors, so have selected one of the few (I think) that be located outside, i.e Powerwall. The new Enphase batteries can also be located outdoors but do not seem available in UK yet and I think there is a German model also. My rationale is fire risk. I appreciate that Solar PV panels can also cause fires - so have gone for micro inverters. Reasoning is based on quite a few years in the speciality renewable energy insurance market, e.g. insuring large Solar PV install in the US - many on roofs and with batteries, and the various real losses that occurred.

Hi @S2D2 am afraid my consumption is pretty much best effort estimate. I itemised appliances etc. now and future and validated against actual consumption - came quite close to actuals. Have taken a conservativ'ish on the resulting space heating requirements post my enerphitish refurb, i.e. @45 - 50kwh/m2. Other than that probably being a bit naive but basically think I am optimising what can be done (and know I am spending a lot of post tax cash) but view it all as a bit of alternative hedging and given inflation (which I am discounting) of both electricity and kit think a 10 year return is OK - equivalent post tax to a 7% return on equity - and given my personal circumstances quite happy with that.

Hi @Radian contractor install I'm afraid. Was a bit worried that I had dithered too long .. should have commited back in May. Understanding is that the Solar PV will be installed soon and Powerwall next September! Just going my optimistic view on number of panels, i.e. 11, will be realised. Panels should be Sunpower Maxeon 6 AC - ideally 440w, possibly 420w, each with an enphase microinverter. @SteamyTea yup, haver the Zehnder Comfoair Q600 with enthalpy. Cheers

An update, have bitten bullet and decided on Solar Pv - Sunpower Maxeon 6 - hopefully about 5.2kw and Powerwall 2. And having done the sums, the total energy saving gadget package of ASHP, MVHR, Solar PV, and Powerwall will have payback of about 11 years assuming some sort of E7 currently capped tariff. And payback 10 years with export such as the Tesla tariff. Assuming energy costs go up, e.g. no cap, then payback will obviously be better. Plus, I am guessing given inflation & related demand panels and battery may be more expensive. Also @SteamyTea have decided on a small laundry room with UFH and MVHR extract - so I will follow your advice and hang things up to dry

We are replacing our Viessmann 222F gas boiler with a Viessmann Vitocal 200A ASHP. Viessmann are handling the BUS grant, EPC, etc, for us. Its a new scheme and we are one of the first. We cannot remove our boiler and terminate our gas contract until Viessmann had done all the paperwork. Cheers

Thanks to all, cheers

Hi, I am hoping someone might be able to advise. Am trying to find out which are the "best" recirculating kitchen extractors that can be built-in (aka integrated?) 650mm above 800 -900mm wide induction hob - and which can be fitted with an active carbon filter. I stress the built-in / integrated aspect of this. Our home retrofit will be relatively airtight and we will have a Zehnder mvhr with appropriate supply & extracts throughout the house. Was interested in the Falmec "no drip" extractor models but seem impossible to source in the UK. "no drip" as they have an interesting solution to catch condensation - we have a temporary rental and have observed this problem in spades. Also I very regularly cook / griddle fish - hence need for a really robust solution. And would like to minimise our exposure to cooking generated PM,.5s! Thank you in anticipation, cheers

Hi @Jenni thank you

Hi, I am considering installing recessed track in the ceiling rather than have a surface mounted track. The ceilings will be new. However I have been advised by our contractor (who has many years experience and who I greatly respect) not to have recessed tracks as the plaster invariably cracks. Does any agree with this point or have you had a better experience? Thank you in anticipation Cheers

@JamesPa Yes, they are interesting. The quoted electricity requirements for the fans appears minuscule. We are provisioning electric points in case we need to fit the fans. I have slightly undercooked the radiator output as I know what our old radiators put out with our very drafty victorian terrace in our upstairs rooms - obviously benefiting from convected heat. So bit of an insurance policy.

@Wil apologies just spotted your question - its jaga - my mistake. These are the ones we are going for, cheers https://jaga.co.uk/wall-mounted/strada

Did also find a hack for building your own fan unit on a German website but the cost was not too far off the JAG units.

We are fitting JAG radiators as part of our retrofit. I have deliberately selected slightly lower output models, i.e. depth and width (height whilst affecting output has less of an impact) referring manufacturers tables. I know how we lived in our very drafty victorian house with its relatively cool radiators. So given our Enerphit'ish retrofit am betting on requiring less energy than per the calculations. However, as an insurance policy have selected the slightly deeper, starting at 115mm I think, for some rooms so I can fit the JAG fan solution. Assuming they are accurate it is slightly gobsmacking to see what a positive difference they would make should we feel too cold. Obviously am having power supplied to each rad where fans may be required. Wet UFH throughout the GF and rads on the uppers, Viessman split ASHP.

Hi @Ommm did conclude I was mad. So option is possibly adding a cooling unit as part of MVHR. Current plans are Zehnder ConfoAir Q600 with Enthalpy (have been flamed already on this!) and therefore considering ComfoCool Q600 as add on. May either do it now or design for it later. Has anyone got any recommendations for radiators? My guess is that they will be aluminium as we will operate at low temperature. GF will be UFH throughout. ASHP will be a Viessmann split unit.

Am I mad? I am considering using radiators for cooling. We will be relatively airtight and insulated with an MVHR and ASHP with UFH on the ground floor with low temperature, e.g. yet to be decided but probably aluminium, radiators on the uppers floors. Radiator pipework will be plastic and located in underfloor / ceiling voids. Googling around and reading through this post, including https://github.com/aerona-chofu-ashp/docs/blob/main/guides/cooling.md I see comments regarding condensation and effectiveness. Has anyone got real life experience of this or has a strong view against such an idea? Cheers ... enjoy the hot weather whilst it lasts!

@SteamyTea Wow ... whilst I live down "in the smoke" pollution from vehicles, at least where we live, is thankfully not an issue though we support the low emission zones. Our neighbours, typically yummy, tend to own at least two vehicles one of which is usually of the 'Chelsea tractor' massive 4x4 type. We even have one who has two Land Rover types with multiple jerry cans strapped to the roof - I suppose I was young once.

Hi @JohnMo wish to ensure relative humidity levels are maintained between 50-60% as we will have extensive and very expensive wide plank wood flooring throughout. We are based in London and our house has always been very dry - there are just the two of us and it is large and being an old Victorian is (was) very drafty - I monitored relative humidity from Jan through April which was between 35 - 40% so have concluded that our energy improvement measures particularly MVHR might even further reduce this at worst. Therefore, de risking with enthalpy unit. Thank you for your feedback. Do you have any thoughts regarding @Ultima357 solution re wood smoke? This is probably my greatest concern going forward. Wood burners are a fashion accessory in these parts along with farrow & Ball etc.

Our Enerphit’ish renovation is well underway and am thinking ahead regarding air quality both from the point of at project completion and ongoing thereafter. I have got a thing about particulates, e.g. PM2.5, particularly (hah) because of the idiots (we are inner London) and yummy parents who have installed wood burners which have previously caused serious breathing problems for us in our very drafty Victorian. I also have been ruminating about Formaldehyde off gassing particularly immediately post renovation. So some thoughts, and would be interested in any feedback: Materials We will be largely using wood fibre IWI but I still need consider its formaldehyde content. Also, use of MDF, e.g. for built in furniture / kitchen units, which is available as low / zero Formaldehyde products such as from Medite, who were incredibly helpful when I called them up. Project completion In researching PM2.5 air quality monitors came across a very interesting website https://smartairfilters.com/en/which has lots of very useful info in particular https://smartairfilters.com/en/blog/how-to-run-formaldehyde-cookout/#more-20301 which outlines an approach to accelerate formaldehyde gassing off after a renovation. I am very tempted to do this but need to understand what the impact might be to our planned engineered wood flooring on basis I would use temporary electric heaters to raise the house temperature and how I would need to set the MVHR (will be Zehnder enthalpy unit). Ongoing Wood smoke I am going to see about installing an active carbon filter something like as described by @Ultima357 in comment https://forum.buildhub.org.uk/topic/22212-mvhr-active-carbon-filter/#comment-348128 as well as a F7 filter on MVHR intake to mitigate wood burner smoke. Cooking Inevitably am going to have recirculating hob extractor but am either going to add an active carbon filter or something like the https://www.plasmamadefilters.co.uk plasma unit though would be interested to know how effective these actually are. Also, there will a MVHT ceiling extract in the ceiling somewhere. Air quality monitor I will probably have something like the ‘Airthings View Plus’ monitor as it can be used with Homekit (we are an Apple household) and possibly small air purifier, if monitoring highlights a problem, such as the https://smartairfilters.com/en/product/the-sqair-chemical-warfare/.