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Charging using 32amp Commando and mobile charger
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PITA
Model 3 Performance
... and then you bought a Tesla
Probably been better off with a 1980's Ford Escort Mk2 1.6 L
We have no electric heating in the house so that's not an option. We have no electric water heating or aircon (I don't even know anyone that has aircon) so that's not an option either. I am talking about nightime hours after 11:30pm/midnight so normally no lights anywhere. We have some solar "security lights" that only operate when triggered. We have a mains security door light that might be triggered by the cat for 30 seconds. We are running a 15 watt UV tube on 24/7 for water treatment and we have a fridge/freezer. The other items like the alarm system, wifi router and wifi switches and device chargers are tiny power users.
WannabeOwner
Well-Known Member
Me!
But I don't think I know anyone else.
My view is that modern houses should be insulated to the point where they need negligible Winter heating / Summer cooling, at which point the cost of providing, and running, it is tiny but the benefit for comfort and health is large. My Air Con comes on (only) when our PV is exporting to grid, sadly the house is so well insulated that it doesn't even begin to use up my surplus PV on "boiling hot days"
I'll step back on this one, because here in the states that would effectively be unrealizable. And honestly, I believe that you couldn't do it anywhere. At an absolute minimum, you have to exchange inside and outside air to live healthy. And conditioning that air can be expensive. Simple things like windows become problematic.
Today's only a warm day at 86F
As a pointer if you want to keep diving into this side topic, research Passivhaus.
I've done a fair amount of research on efficient houses; I was actually working for some companies that were investigating them a number of years ago.
Simply put, if it is a solution, what countries have adopted it? Pretty much everything I said was mentioned in the Wikipedia article about it. Don't get me wrong, it's a great selection of energy saving ideas, but implementation as a whole just really isn't feasible today.
As I alluded, in the UK, there may be some locations and price structuring that would allow it to be implemented, but move North or south and it becomes expensive and problematic.
From Wikipedia
In passivhaus buildings, the cost savings from dispensing with the conventional heating system can be used to fund the upgrade of the building envelope and the heat recovery ventilation system. With careful design and increasing competition in the supply of the specifically designed passivhaus building products, in Germany it is currently possible to construct buildings for the same cost as those built to normal German building standards, as was done with the passivhaus apartments at Vauban, Freiburg. On average passive houses are reported to be more expensive upfront than conventional buildings – 5% to 8% in Germany, 8% to 10% in UK and 5% to 10% in USA.
Evaluations have indicated that while it is technically possible, the costs of meeting the passivhaus standard increase significantly when building in Northern Europe above 60° latitude. European cities at approximately 60° include Helsinki in Finland and Bergen in Norway. London is at 51°; Moscow is at 55°.
And honestly, I don't think that the upper percentage for the US would come anywhere near the ability to provide 80% energy reduction in many areas.
PITA
Model 3 Performance
Me!
Toshiba Haori system.
Our home Air Conditioning is famous amongst my Sons friends, as he's the only one online gaming with a jumper on in the height of Summer. Whilst all his mates are sweating and moaning about the heat.
I like ours because it has a Plasma Ionizer Virus catcher built in, so filters the air as they're working.
Installing a Hybrid deCentralised MVHR system this year with F7 HEPA filters as well, to compliment full climate control.
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cryo
Member
I have the same system and one thing you also gain is when on in air purification it also removes pollen, listen up all you hay fever sufferers as there is far more to air to air heat-pumps than the low running costs.
WannabeOwner
Well-Known Member
Passive Haus is well insulated (there is a calculation (PHPP) which works out how much insulation is needed, given local temperatures etc. etc. to reach the required specification for heating / cooling energy annually)
In addition to insulation the building is airtight - membrane in the wall, and also building techniques that prevent air loss
Then mechanical ventilation is built in. That introduces fresh air to "living" rooms (inc. bedrooms) and takes exhaust air from wet rooms (bathroom / utility / kitchen). The exhaust air passes through heat exchanger and most of the heat / cool is recovered.
One option is not to install central heating and use the money saved on the increased cost of build (about 6% more) and just turn on an electric fire in "really cold spells" - a 3-bedroom passive haus needs about 1kW of heat. Also saves on boiler maintenance each year, and replacing it every decade or two. Air Con can be added in the ducted air, or just have a portable unit somewhere in the house and the ventilation heat recovery will move the "cool" around.
Heat, in Winter (in UK climate at least) is mostly provided by the people in the building, and heat sources like cooking / electronics.
If we go away for the weekend in mid Winter (UK - as an example assume 5-10C day and 0C night) and turn everything off the house would lose around 1C. In practice we wouldn't turn the heating off - so that we maintain the heat in the thermal mass of the building
Once the building is well insulated the amount of energy lost is tiny ... and heating / cooling is tiny. So the cost is also tiny.
Passive Haus heating / cooling requirement is 15 kWh / sq.m / year (guess that is about 1.5kWh per sq.foot). I'm curious to know what your heating / cooling usage is for the year?
EDIT: I found this conversion "4.75 kBTU per square foot"
They need to be properly designed to make the "insulation layer" continuous with the insulation in the walls, and have no cold-bridging (a surface that is "connected" inside-to-outside and thus radiates temperature to the inside). It is normal to use triple glazing (which has become commonplace in EU anyway).
In our house there are no connections (cold bridges) from the outer brick wall to the inner (block) wall. In a traditional UK house there would be a lintel above the windows that was one solid piece, radiating outside temperature into the house. We have two separate lintels - inner and outer. The "ties" between the inner / outer materials are glass fibre rather than traditional metal ties - so no heat / cold is transmitted. Lots of insulation in the cavity, and below floor / in roof
The principle of Passive Haus for windows (as I understand it) is that the inner glass surface must not be more than +/-4C compared to the room temperature. More than that and convection occurs moving the layer of air next to the glass (falling if cold, rising if hot) and that created the feeling of a draught. Passive Haus design ensures that doesn't happen, which then leads to better comfort.
Having a roof overhang on South side keeps high mid Summer sun off the windows ... but low winter sun comes in and warms the room.
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WannabeOwner
Well-Known Member
Temperature in my house very rarely goes outside 21C -23C I am in shirt sleeves the whole year, haven't worn a jumper in the house since we moved in
The mechanical ventilation air is filtered - so no pollen etc. Passive Haus is renowned for reducing respiratory illness. In the 7 years since we moved in neither Wifee nor I have have had a winter cough/cold (had one every winter before then), and Wifee was working in an open plan office with everyone around her dying all winter. So just the benefit of 12-ish hours in good air makes that difference.
People I speak to assume the house must be stuffy. Those who come here comment on the air quality
Air changes are more than for an old draughty Victorian house! and because the vents are designed, rather than just having ill fitting windows, the air gets into all the corners - so no lurking mould spores, which are typical in UK housing stock in winter. My advice to anyone contemplating a forever home, or anyone with respiratory illness, is build a passive house and have the comfort, financial and health benefits for the rest of your life
WannabeOwner
Well-Known Member
I went looking for a post I had made including house temperature graph and found a thread about Allergies and Migraine which has a good discussion about Passive Haus, mechanical ventilation, filters and so on. Would be a better place for discussion for anyone who suffers from allergies or respiratory issues or is interested in Passive Haus
As I mentioned in my first post on the subject, I'm in the US, Georgia to be specific. Believe it or not, the entire world doesn't have the temperate qualities of Suffolk. We don't have the ocean effect to reduce the fluctuations in temperature.
So sure, in Suffolk the temperature in your house may only vary from 21C to 31C. That's because Suffolk only has a 15C outside average temperature swing.
In Atlanta, we've got a -10C to 40C swing that occurs here. In the northern part of the country, it can get down to -20C
And I am quite familiar with heat exchangers. I had one in my last house. While they are around 80% efficient, during the winter, they pump in relatively cold air. Cold enough that you can feel when the exchange is on.
WannabeOwner
Well-Known Member
We had 38.4C on successive days during the two week heatwave last July (and unusually had a second heatwave in August), and in December we had nights down to -8C during a week when the day temperature didn't get above 0C. So not the rosy maritime climate that you assume we have all year round.
So ... my house has been tested at both those temperatures - but that's the point - the insulation and air tightness keeps the winter heat in, and the summer heat out- by design. But if you don't think it has any relevance to you, that's up to you.
I live in a Passive Haus. That just does not happen - even when it is -10C outside. MVHR units here (i.e. Passive Haus certified) are rated 90-95% efficiency.
My wife and I did it primarily for eco reasons and only since we have moved in have we realised just what a dramatic difference it makes to quality of life and health, rather than just wallet. Therefore whenever I get the opportunity I recommend that people consider it.
Top hit from google, site from 2017: Passive House in Georgia …. Anyone? – Imery Group Custom Home Builder, Renovations, Energy Audits Athens Atlanta Still seem to be in business, so must be building some.
We aren't passivhaus, but are slowly retrofitting in that direction using the same approaches. Airtightness. MVHR (92% efficient). Solar for summer power, batteries for winter. Heat pump (seasonal COP of 3.5, up to 7 this time of year, outputs 12kw down to -15 deg C). Our big problem is actually overheating in summer due to some massive west facing windows and a lack of knowledge at the design time of those to know to recess them or protect them from the summer sun somehow. We have some exterior blinds on them this year which is making a huge difference to controlling temps.
Scotland is looking at adopting either passivhaus or something similar in the next couple of years. https://www.parliament.scot/-/media...42022-consultation-passivhaus-bill--final.pdf
Our climate isn't as regularly extreme as yours, but I have personally, in the suburbs next to the sea, seen -10 for a few days and +40 measured by my heatpump (not formal weather number). Scotland also have areas that qualify as temperate rainforest (if we can preserve the last few bits), and one area regularly hitting -25 deg C (record -27.2). Its not the same 'the snow comes and just stays' as you have I imagine but its not the balmy days the averages suggest.
I guess I'm trying to say don't discount a locally modified passivhaus as impossible. Even up and down the UK designs have to vary and those with the knowledge local to you will know what the state needs. London is considering bringing in a floor area to window ratio rule to stop summer overheating - only really needed there as the city can be up to 10 deg C warmer than the surrounding countryside
.
WannabeOwner
Well-Known Member
Hard to solve West facing (or East) using overhangs / recess because (at UK latitudes) the Summer sun is low enough to come straight in during the Evening
We've solved our downstairs East facing ones with a Pleach (of Limes, 'coz that was fastest / cheapest
) which being deciduous keeps the sun off during Summer, and lets it in in Winter. No help for upstairs windows (toot all to trim !!) but trees, further away, would do - but longer to wait.Exterior shutters probably the best fix
I did a bit of Googling and turned up the "PHIUS+ 2015 Passive Building Standard" (North American standard) and it seemed to have a number of useful statements along the lines of "We get why the physics of Passive Haus works, and the Maths (PHPP) is important too, but it needs adaption for both House Size (particularly smaller houses) and Location"
My understanding was that Location was already considered ... but if there is a body considering specific alterations for North America climate (and also for regional variations of course) that seems promising.
Clearly persistent long periods of extreme heat (or cold) needs handling, and whilst my building copes with those extremes, I don't have installed heating / cooling equipment with capacity intended to solve them over prolonged periods (with hindsight I would have installed higher powered units - just like I was perfectly happy with 3s 0-60 until 2s Plaid came along
). Mistake we made was thinking we were building an Eco building with zero energy use, and would put a sweater on in winter, when in fact it turned out that it needs so little energy it is better to consider making it the best comfort possible, which is still a tiny amount of energy.And who knows, we could have catastrophic climate change in our lifetimes, and then having built a home that could withstand far worse temperatures would turn out to have been really prudent. Even if not our lifetimes it may well happen in the lifetime of the building
RedMod3
Member
Oh, we only have electric heating (through choice). We also have electric water heating, solely via an immersion heater. Our whole property is also fully air-conditioned so lovely and cool in the hot weather. But, we also have solar and PWs and so far this month we have bought 1.2kWh from the Grid to power our property and electric cars. All-electric does work. Our EPC rating is a 90, and we just missed the A rating with our very high B rating. The EPC does not consider battery storage.
RedMod3
Member
I certainly agree with a MVHR system. When our property was built in 1989, we had one fitted and we were airtight. The MVHR system kept the air fresh. However, one winter it failed and overnight we had condensation on a couple of double glazed windows. Fixing the MVHR system cured the condensation.Temperature in my house very rarely goes outside 21C -23C I am in shirt sleeves the whole year, haven't worn a jumper in the house since we moved in
The mechanical ventilation air is filtered - so no pollen etc. Passive Haus is renowned for reducing respiratory illness. In the 7 years since we moved in neither Wifee nor I have have had a winter cough/cold (had one every winter before then), and Wifee was working in an open plan office with everyone around her dying all winter. So just the benefit of 12-ish hours in good air makes that difference.
People I speak to assume the house must be stuffy. Those who come here comment on the air quality
My advice to anyone contemplating a forever home, or anyone with respiratory illness, is build a passive house and have the comfort, financial and health benefits for the rest of your life
WannabeOwner
Well-Known Member
Just some detail about our house.
Technically we only have a passive haus extension; because it was very very hard to upgrade the "old part". Having done that we were so impressed with the MVHR we decided to retro fit it to the old part (which, luckily, was already very air tight).
The old part had been upgraded from original - double glazing, cavity fill, loads of insulation in loft, insulation around all the window reveals and so on
What we had done was to swap a hugely inefficient building, with massive air leakage allowing pletny of fresh air / air changes, and loads of heating - which probably, back-in-the-day, took care of moulds etc. - for an air tight, minimal air change, well insulated, minimum heating, building. Loads of condensation on windows in the morning, and mould spores for sure (even if no actual mushrooms growing on the ceiling!)
We installed MVHR in the old bit and that completely solved the condensation and improve the air quality hugely - much as you described after yours was repaired. We are really really pleased with that - but we wouldn't have done it but for our positive experience of MVHR in the new part. Blooming nightmare to accommodate retrofit MVHR as the air pipes are large diameter, so may not be possible/easily in other houses.
Thus I concur with your experience that MVHR helps with condensation / air quality.
But ... the building has to be made very air tight for it to work
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