Oz07

Wicked performance for that size cavity declan do you have any special upstand at floor perimeter or just 25mm? What u value is that wall with those graphite boards?

Lol I bet steamy tea does though. Declan do you have a fire apart from wood pellet burner? Dave how often do you light yours?

That's lock stock though isn't it @jack like steamy tea includes even appliances etc etc. Heating alone is the most accurate measure as Dave says

Similar in roof too then? Do you have an insulated foundation?

I'm pretty impressed with @AliG number tbh thats what started this thread. To have an air score of 9 or 10 and still to be coming in at 50kwh on the heating made me question all the hard work I did getting this place air score at 1. For the boffins - is it a case of the more volume the better efficiencies you get with heating - 900m2 is probably the biggest place on here!

those the figures on the meter

@ProDave i've dangled the carrot for him!

@JamesP figure is pretty good as well actually if that includes DHW? Whats your construction method and rough insulation details?

c'mon @joe90 make the effort just look at a couple of bills! mind I suppose you'd have to estimate heating/other split usage @Declan52 you and @ProDave have the best performing up to now. Yours is pretty traditional construction isn't it declan? What width cavity do you have and what's in floor and roof? @tonyshouse post your numbers here @PeterW cmon I bet you know your figure?

I got told occasionally MVHR can make a SAP score worse, but perhaps that is with a crap assessor? Also I remember reading at any air score below 3 they should start to save more energy than they consume but perhaps this is just for the leccy they use? Not allowing for increasing standing losses? OK I am getting seriously sad, just looked at meter before and after my shower difference of .253m3 is 2.874 kWh on the online convertors this is bringing my total kWh down by over a 1000 a year. Thats excluding the missus and and hob cooking and washing pots. I'm feeling better about it now!

Yes @AliG as @ProDave said earlier if you can seperate water out its a more accurate reflection really. I was disappointed at high 60's all in if I can be bothered I may see how many units the meter clocks up on a shower and boiling some veg - how sad! I think I need to get that new MVHR unit on and balance and temper it down a bit, is yours all tuned up @AliG? By rights they do say that anything above 3 on an air test and the MVHR is uneconomical but your heating figures are not to OTT @MikeGrahamT21 how old is your place? @JamesP i'd seperate out the other electric usage if I was you, not really relevant to house performance. At the 4500 figure your m2 rate looks good!

Is the sane argument not made in reverse though for picking mvhr over extractor, as in extractor expel a lot of air you've paid to heat?

Does that include all electric or heating and dhw ?

I'll be interested to see if mime reduces on a per annum basis. Sap estimates closer to 40kwh m2 @ProDave Good point about hot water not being anything to do with house performance per se. Unfortunatley i can't separate mine unless I start measuring things. Still no comments on if mvhr increases your heating demand. Even allowing for opening bathroom Windows and running extractor for 40 mins a day in the old place I suspect the mvhr system here gives me more loses over 24hr. So much for heat recovery!

Is your water ontop of your figure then? Ie just for heating

Good idea

@ProDave do you have a separate meter on the ashp side of the leccy?

Btw you can alter the drawer sizes on these on site done it myself in the past

@Mr Punter do you have mvhr? In terms of usage my missus likes baths, I'm in the shower for minimum 20 minutes every night and we have thermostat set at 20. My last place was 1.5 storey 6"pir below b&b 6" dritherm 34 in cav and about 8"pir in vaulted ceiling with a small area of flat ceiling 350mm earthwool. I feel like the boiler worked less to keep that the same temp. I do remember Jeremy saying 1.5 storey most efficient shape house?

I think kWh is a much more standardised measure. Would it have a clue what Declan pay a for pellets but we can see that his house consumes lot less than mine. If you're on gas be easy to work out

About 2 inch with a gap in the middle for waste

That's why wood burning people have got to declare also. Would skew the figures otherwise. I'm beginning to be convinced these mvhr systems significantly increase your heating need. Either that or mine is not working properly. I haven't balanced it yet but will do when I get time to put the replacement unit up.

Sorry @Ferdinand I see what you're saying. Yes it effects the figures in that case.

Why is that useful? I want to know consumption not generation. I bet these solar farms generate a lot of leccy but wouldn't be very comfortable living underneath a panel

Piss poor effort @nod just confuses things. Dig out a bill and give us some kWh I've seen the coat you make your missus sit on the sofa in!