anonymous

Currently it's gas by the combi boiler I intend to get rid of gas eventually however

Thanks. So I may as well get the Arastor instead?

Ie: that's the "heat and hot water" cylinder thing? So I may as well explore heat pump water heater cylinders line the Arastor / Joule instead? And then also some form of heat battery?

I imagine that the Arostor does indeed store the hot water too, which might mean that I could get it working on gas too? I guess I would also need a duct I believe you're right RE: the "heat and water" cylinders, so the Arastor would be cheaper still? Given the COP I've since seen this And I'm not sure if the Joule stuff would be any better? Also I guess again the issue is that it's not a heat store, unlike the "heat and hot water cylinder"

So this is only vaguely related to energy storage, in the sense that heat / water is stored There's this company https://heatandhotwatercylinders.co.uk/works-with-octopus-energy/ Their cylinders work with Octopus agile, after talking to them and they also store heat as well as water, which helps. That, and they can be put in "now" given they're able to work with gas boilers too It basically stores that energy at a 1:1 ratio ie: the COP is 1 The Vaillant Arastor is a "heat pump hot water heater" which doesn't store heat but it does store water. The cylinder pulls in air from it's surroundings and on paper, the COP is 3.3 Given this would be inside the house, it means that the COP probably will be around 3 on average as realistically, the average house doesn't fall below 5C even with the heating off. What the Arastor doesn't however do is store heat. It also doesn't "work with Octopus" I'm not sure if you can put this in "now" too ie : by adding something in now, you can stage your implementation a bit which is a bit nicer on the wallet. I guess you could also get a heat battery alongside the Arastor but that just adds costs and complexity Which would you go for and why?

Hey Sorry. I haven't been here for a while. I got a score of 7.66 and mostly they found draughts around windows / doors + they odd bit of piping So I've got some of that sealed up. Though realistically, given I noticed condensation on the odd window, I'll probably get shut of them anyway as part of my long term plan

The only extractor fan I've got is in my en suite / kitchen tbh Other than that, I have no trickle vents, though I do have some vents underneath the loft part in the attic

Ah So around 32.5 KwH / Square metre for space heating which would be an equivalent of 3870KwH a year of space heating for myself And then also 10.75KwH/sq m for water which means that if my house met that standard I'd need 1290 KwH for water heating Thanks

This is fair. I have Properla on my walls outside but that's it

That's freaking amazing. Could you go for an easy win, and bang an ASHP in there, and immediately reduce your usage from 48 KwH/sq m?

So essentially you went down from 141kWH / sq.m to 111 KwH / Square metre in the first year alone

Thanks. May I ask what size your house is, in square metres? Essentially I'm wondering what your kwh/ square metre was before installing the MVHR and in the first year of having the MVHR It does appear you've saved 26% with just an MVHR though which is bloody impressive If possible? Thanks

May I ask how much energy usage dropped in the first year, even with a leaky house?

I've already had my air tightness done yesterday. I'm currently at 7.66 He advised me that I could get it below 5 easily, and maybe even lower once I seal up the parts identified in the test.

Tbh I'm looking to use PassivHaus principles as much as possible, and for as it seems worth it regarding costs / benefits In that sense, air tightness and an MVHR seem key at the very least

So I've had a quick look see on Barratt Homes, found a new build, and there's quite a few in this postcode area. It isn't my postcode or close to me but I figured Barratt homes would have some new ones even if they're not known for having the best homes about It seems that they more or less use 35KwH/ Square metre when it comes to heating So that's something to try and achieve using enerphit https://find-energy-certificate.service.gov.uk/energy-certificate/0632-2531-7000-0464-4292

So My aim is to get my existing house to be more efficient, and I'm someone who want to work with PassivHaus principles but not necessarily entirely given you get diminishing returns Newer houses aim for an air tightness of around 5 or below I believe. Does anyone know how much KwH per square metre they typically use? I ask, as it should be possible for me to go from an air tightness of 7.6 to 5 quite easily, it not below that (Which is obviously what I'd want, cost permitting)

I live in a 1970s house, and right now the air test has a score of 7. I've talked to the air testing person who's said that I should be able to get it to a score of 3 by doing remediation work that he's mentioned, and if not 3, definitely a 5 Given that's the case, should I bother with an MVHR? Thanks

Yup. I've already got a ballpark quote from the "greenbuildingstore" RE: an MVHR

They know that I'm going for PassivHaus compliance but not necessarily the certification They also know they they'll tell me how to remediate them

This is for a retrofit. The reason why I ask is that I assume that if my house is super airtight, then that potentially leads to mould issues? Perhaps getting it done the other way around, would perhaps prevent mould issues? Or is mould issues simply rectified by opening windows?

So probably under 1K to get it air tight?

I've got a 1975 timber frame semi detached 120 square ft house, which is already well insulated but I want to make sure it's air tight. There's no point having insulation if I'm leaking air and it's costing me £7/day just to maintain one temperature.. I understand that obviously the cost of getting it to be air tight can be quite different, but I was wondering how much such a thing has cost others? I'm getting an air tightness test next week Thanks

I'm factoring absolutely zero solar gain, largely because the house already exists, so it's just about upgrading to retain heat inside

Thanks. I live in greater Manchester, so when I update my Windows I'll go for triple glazing instead of quad glazing