Average Electricity Consumption

[billi]

Hi Billi,

Not sure how the German utilities work but assuming they’re going along similar lines as other European countries and the uk I would suggest grid tied - just depends on your long term plans / equipment mobility and as Stinsy is asking what the costs of being grid connected are.

Moxi

Hi Moxi , i might or will buy that house , but its not in rural Ireland in the middle of nowhere anymore , where i just did what i want ,

But in principal , same thing again , to avoid letters and invoices and paperwork in the letterbox is priceless

I would rather prefer to ask the neighbor to lay a cable across the field and i feed surplus into his grid connected house than ..... well me going into radical dreams now

[John_S]

Annual consumption is a moving target.

In 2008, it was around 4,300kWh. By changing halogens for LED, installing solar panels in 2010 and the kids going off to uni etc, I managed to reduce it to just below 2,000. Then I got a PHEV which sent usage up and now a BEV which increases it further.

I think I need a meter between the Henley block and the mini consumer unit for EV charger, so that I can get some more comparable figures going forward.

[Stan]

There’s a very thoughtful man on The EV Puzzle (youtube) who experiments by changing most of his energy equipment, including cars, very regularly. One comment which I noted was that having an electric car made him feel that he had more freedom to travel (without guilt). His experiment of having only simple electric heaters using battery storage and 5p Octopus Energy units also made him use power more freely.
It’s well worth listening to his fertile mind arguing for and against each move.
Essentially his mind is struggling through all of the energy quandaries that mine is. He really wants to avoid fitting a heat pump with all of its expense and upsets during installation.

[Petertc]

Interesting looking at the figures. Also the dilemmas.
We have a 4 bed 1980 house. 4 to 5 of us as son at uni.
GHW, GCH combi boiler. the first year we moved in our gas usage was 16000Kwh, which was a bit of a shock.
We replaced some old double glazed unite, added extra insulation in the loft. Then had cavity wall insulation fitted. Gas usage down to 9000 Kwh.
We have found that it's better to leave the heating set at a constant temperature. Rather than vary it during the day. We think it's the floor slab that pulls out the heat. Its a laminated floor glued directly to the concrete. So not ideal.
Electric usage we use about 1600 KWh a year. I have since added a diy grid tie 1.1kwp pv system. This does about 900 KWh a year.
We also have a 5Kw wood burner. We just use this occasionally.

[snootsandfruits]

Its a laminated floor glued directly to the concrete. So not ideal.

Have you come across any particularly good products for this issue if you were going to replace the laminate?

We've just moved away from a house with solid concrete floor but at least for carpet I stumbled across this underlay from John Lewis with a TOG of 3.43, one of the highest I've seen while still being breathable and 100% recycled.
https://www.johnlewis.com/john-lewis-pa ... h/p2401207

I've seen a few wool felt underlays for laminate but with very few ratings for their insulating value either in R or TOG.
Compressed wood fibre seems like it might be the best option as XPS foam isn't moisture permeable, but I suppose neither is most of the surfaces that might be put on top of it.

A good friend of mine has just bought a house with a similar uninsulated concrete slab and was also looking for advice.

[Stan]

The vitrex underlay sold with laminate flooring has U=0.024W/mK but is only 5mm thick.

[snootsandfruits]

That's wood fibre right?

I think 5mm is about the maximum I've seen too, which makes sense to not raise your floor height too much, but could definitely be better in terms of insulation.

[nowty]

The vitrex underlay sold with laminate flooring has U=0.024W/mK but is only 5mm thick.

Your mixing your units up, W/mk is not U as U is in W/m²k.

Immediately if someone tells you a 5mm bit of insulation has a U value of 0.024 its complete nonsense.

What is quoted is the thermal conductivity, lambda (λ) or (k) value in W/mk and is independent of thickness of the material, well its actually based on a standard thickness of 1m or 1000mm, but that board is only 5mm thick. To calculate the U value you first need to work out the R value which is the actual thermal conductivity in terms of the material thickness.

So the thickness is 0.005m, the R value will be 0.005 / 0.024 = 0.2083 m²k/W

And the U is the reciprocal, so 1 / 0.2083 = 4.8 W/m²k

So does not look quite so good but its still about 3 or 4 times better than laminate flooring of the same thickness.

[Stan]

Yes, I did rush that post Nowty. But there is something wrong with your last comment. I just went to der shed and put my lip firstly to a piece of Vitrex and then to a stored sheet of window glass. The difference in conduction is massive (obviously the Vitrex feels warmer). Ambient temp out there is 3C.

[nowty]

Yes, I did rush that post Nowty. But there is something wrong with your last comment. I just went to der shed and put my lip firstly to a piece of Vitrex and then to a stored sheet of window glass. The difference in conduction is massive (obviously the Vitrex feels warmer). Ambient temp out there is 3C.

Yes but that's what it feels like, not what the transmission of lost heat would be from the room into the ground. There has been similar arguments about thermal paint, it does not stop the heat loss but the room temp can be slightly lower to feel the same comfort. But in this case its irrelevant because the insulation is not on the exposed surface.

My kitchen floor (10cm of foam underfloor insulation) with porcelain tiles need to be electrically heated to 3 degrees higher than my lounge Oak floor (5cm of foam underfloor insulation) to feel the same comfort under barefoot.

I just hate manufactures giving misleading data on their products, although to be fair they do use the correct units, but the boards would need to be 1 metre thick.