Garald

OK. I'm contacting another electrician (based in Paris proper - he comes with a very good recommendation) and telling him that I only want a WiFi access point in every floor, but I'm also considering some automation (for an alarm, possibly for security cameras, and also for opening the door remotely, in case I ever let the downstairs studio or just want to allow a friend in; the Philantropic Flipper also mentions that he regulates the heating remotely, but I don't see what that's good for - just so that one doesn't have to wonder whether one left the heating on? Or in case one is away for a sabbatical and doesn't want to make a local friend come in to turn off the heating completely at the end of winter?).

Wait, that happens? It has got a bath only on the very rare occasions it has had an, um, accident.

I should have made clear that we are working under the assumption of a *high-temperature* heat pump. Whether it would be wise to switch the entire network to low-temperature is a different, important question, which I will ask separately.

No TV area because no TV (I'm ending the TV connection, actually). A WiFIi access point in the (shared) garden might be a nice gesture to win the neighbors over. (The same goes for all improvements to the garden - I plan to do some, but I haven't put *that* in the budget yet.)

> 'Weak-current network'? Never heard of the phrase, and Googling suggests it's a very little used term. Well, I'm translating from French! I have used a wired network at my own place only once in my life - early in the pandemic, when I was trying to figure out the reason why JamKazam was so slow as to be unusable. (Hint: no, it wasn't the Wifi.)

[Preface to this and several other questions I am asking: Well, the planning stage is over, and we should start working soon. And guess what, my architect has just presented me with a huge bill courtesy of her contractor for me to approve - much larger than the budget I had originally fixed. So, we now have to sit down and negotiate - and go through every unimportant, expensive detail that can be taken off. ] I am doing a pretty thorough renovation of a place I bought recently (as some people here already know). The architect is proposing a 300L hot water heater. However, this is a 110m^2 place (well, 184m^2 if you count both the places that are not currently inhabitable as well as the places you cannot stand in), meant for myself, my girlfriend, my parents when they visit, a cat, the occasional wandering mathematician - not a large family of amphibians. A friend who is helping me go through the details says that 120L should be enough, and 150L largely enough - anything above that is an unnecessary expense and also makes matters less efficient. Is he right? What size would be reasonable for my sort of situation? (This is a heater I am getting in conjunction with a heat pump - not sure how the two relate to each other, but that's not the main point of the question.)

Preface to this and several other questions I will be asking: Well, the planning stage is over, and we should start working soon. And guess what, my architect has just presented me with a huge bill courtesy of her contractor for me to approve - much larger than the budget I had originally fixed. So, we now have to sit down and negotiate - and go through every unimportant, expensive detail that can be taken off. The totals for electricity, painting and laying floor are particularly enormous. Here comes in my friend, N. the Philanthropic Flipper (banker by day), who has been of invaluable help to me in the past (and present). He pointed out (among other things) that the bill for redoing the entire electricity system (which does need to be changed entirely: the current one is clearly the fruit of 90 years of DIY) includes RJ45 entries in virtually every room. He says that an RJ45 weak-current network is not needed to begin with (or even common in new construction or renovation jobs), and thus is an unnecessary expense, besides being bad for the environment (all that cable). I should be fine with a router per floor (and I agree; in fact, in my current place, I like turning off my one and only router in the morning so that I can focus fully on my work). Is that right? Are RJ45 weak-current networks (which I had never heard of before until now) both expensive and unnecessary? (The architect may honestly think that people who are science-y fields need to have their brains directly wired to the Internet.)

I'll just include some links to the insulation materials the architect is proposing, for ease of reference. The price is surprisingly sane - around 20 eur/m^2. https://www.ati-isol.com/gammes/isolants-respirant-hpv https://www.materiaux-naturels.fr/produit/1468-iso-lin-hpv-isolant-mince-reflecteur https://www.isolation-itr.com/non-classe/thermo-laine-lin-2.html http://www.isolantmince-discount.com/fr/isolant-mince/56-isolant-multicouche-m17-pro-lin.html https://www.winco-tech.com/fr/produit/skytech-pro-xl-toiture-isolant/ The only one to have a (very) good fire rating is the last one, which, on the other hand, seems to involve fibreglass, whereas the others contain no synthetic fibres. Same dilemma as usual.

Thanks!

Send me a link or two to get started?

Anything I should be particularly concerned by?

Yet another episode of the insulation saga - perhaps the last one? As some of you remember, I am renovating a (hitherto uninsulated) house from around 1930 in the Paris area. On the south side, I have a bit of space, and I also very much have a need for as much sound insulation as I can get (busy street); thus, unsurprisingly, we are going to use 145cm of cellulose-based insulation (BioFib Trio) - counting an air layer and an anti-fire barrier, we are talking about 18cm or so. On the north (courtyard) side, however, I don't have that much place to play with. My architect considered polyiso (PIR) for a while, but there is some contradictory information regarding its safety in case of fire. Now my architect proposes the following solution for the north side: combine reflective insulation (as in, e.g., https://www.materiaux-naturels.fr/produit/1468-iso-lin-hpv-isolant-mince-reflecteur , which gives R=3.25) and about 45mm of BioFib Trio. In total, the insulation provided is well above the norms (R>=3.8). What is the catch?

Well put, but I might hesitate to rent the garden studio to a known murderer!

A friend proposed sheep wool, but I was advised to pass that by because of, yes, bugs. Here's the link to Biofib, and more particularly to Biofib Trio. As "natural" materials go it seems very good - or at least it is the best we could find. I'll need very good sound insulation (the place is in front of a two-way street with buses, motorbikes and the occasional small truck) and also some moisture control (what I have next door is a neighbor's garden with ivy and other vines). https://www.biofib.com/biofib-trio/ Sacrificing 18cm of staircase would be a bit too much, though, particularly given that I like the staircase. Still no idea of whether PIR or PUR is more advisable...

It's a brick house that will be full of books. Most likely no or nearly no carpets (because of allergies), except for a jute carpet for the cat to destroy. The main danger in case of fire coming from all of that is probably CO. More seriously - the issue is that we are talking about a large staircase that is the one escape route. We'd presumably be talking about the "well-ventilated" rather than the "smoldering" kind of scenario. The wall to be insulated is the one with the stained glass (which will be insulated by a glass pane on the outside). (Warning: bit of stair porn. It's probably the nicest part of the place as of now.) That may be a good idea. But wouldn't one need one in every room?

I'm renovating (most of) a small house - in particular, my architect and I are doing our best to insulate it to R=3.8 (the local standard), not counting the inherent heat resistance of the (brick, masonry) walls. We'll use Biofib (based on hemp+cotton+linen) on most of the first floor - counting an air layer and a fireproof panel, we are talking about 18cm, which is not great but also not terrible. It has plenty of virtues besides being good heat insulation - it has good sound insulation properties, works well in summer, regulates moisture, doesn't slowly kill you (if there is a huge fire and the fireproof panel is breached, you are basically in The Name of the Rose, but it certainly doesn't kill you *slowly*), etc. In some places, though, we simply don't have enough 18cm. We may use a vacuum-packed product in the bathroom (not much of a temptation to nail things to the shower wall, is there). However, the shape of the wall in (a) the toilet (b) (more importantly) the large staircase is just too irregular for the installation of vacuum-packed products to be feasible. Phenolic is not an option for indoor insulation where I am (too much fume). We can't seem to get airgel panels in the local market, and airgel blankets cost a fortune. One can't apply more than 8cm of Fixit airgel plaster (a useful product otherwise). So, by exclusion, we arrive at PUR (polyurethane) and its cousin PIR. I am a bit concerned about using PUR and PIR on a staircase - their reputation for emissions in case of fire is not great. (We'd put them behind a fireproof panel, obvs.) The architect says PIR is not as bad as PUR in this regard. However, this study (from 11 years ago) seems to indicate otherwise: http://clok.uclan.ac.uk/1536/1/Stec and Hull_Fire_Toxicity_of_Insulation_Materials_EnergyBuildings_2011.pdf What do people here think? (Worst comes to worst, in case of fire, I can just jump from the first-floor windows, but, if my parents visit and a fire starts then, they might feel differently, at least for a crucial moment or two.)

(PIR and PUR were thrown about as possibilities, but I would not want to have them in the bedroom because of fire-related reasons. The staircase is the only escape route; of course jumping from a first floor is a no-brainer, but not everybody necessarily feels the same way when under pressure.)

)As some people here know by now, I'm renovating a place near Paris. In particular, we will insulate it. On the SES and WSW sides, we will use 145mm of BioFib Trio (hemp-cotton-linen), meaning about 180mm in total, counting air layers and a fireproof panel; this will amount to R=3.80 in insulation alone. (R=3.7 is some magical French threshold.) However, on the NWN, we do not have that kind of space - we do not have it in the staircase, or in the bathroom, or in the toilet, and we'd rather not lose too much space in the bedroom either (though in principle we could). After a lot of looking around, and feedback from this site, my architect proposes the following aerogel-based product: https://www.fixit-aerogel.com/en/the-innovation Does anybody here have experience with this kind of product? (This is aerogel plaster. Aerogel panels or blankets are not yet available in the French market, for whatever reason. The performance is not at the same level as Spacetherm, but it is still substantially better than BioFib: since the conductivity is lambda=0.028, 80mm would give us R=2.857 (below the norms but already rather reasonable) and 105mm would give us R=3.75. Not sure how thickly one can lay it on, though; my architect suspects it may be brittle.) Is it likely to be safe in the long run for a bedroom? (Fumes?)

The attic in the place I've now got has a very creaky floor - to say that one can hear every step while in the floor below is a severe understatement. It's an attic that was made inhabitable by previous owners; part of the problem is that they put a laminate floor on top of wood, apparently badly. We will fix that, but we want to go much further in minimizing noise. (The floor below has what will be my library/piano room!) I was just proposed something that contains rock wool (https://www.fermacell.fr/fr/produits/plaques-de-sol/plaque-de-sol-avec-laine-minerale). However, the attic will consist mainly of bedrooms, and I've been avoiding rock wool overall, in part because it seems fairly clear that it can cause lung injury. (It is not remotely as bad as asbestos, and it may or may not be a carcinogen, but, given that I have a touch of asthma, and that it is a family thing...) What are some alternatives without rock wool, of similar or higher effectiveness? (We would like to lay actual hardwood on top of the insulation layer.)

Right - my architect is now suggesting 25 to 30mm of TMS polyurethane or Utherm Floor K (PIR). She was telling me that, ironically (it took me a moment to realize she said "ironically" because "pire" means "worse" in French), PIR has a reputation as being "not as bad" as polyurethane. I imagine that that means that we will go with PIR. In either case, that apparently means we will not have hardwood :(. It's wineo (www.wineo.de) for us at that level. Sad...

So, wait, what is not worth the bother? Coating both sides (or one side) of the air gap with a low-emissivity coating (whatever that would be), since that would degrade over time? Shouldn't one recalculate the effect of the air gap as estimated by Actis, then? Very, very roughly, what should I expect? That the air gap should provide half the additional R they claim - whether it's their insulation or Biofib's? Should I expect the two (uncoated) air gaps advised by BioFib (see diagram in my original post) to have roughly what Actis claims for the performance of a single air gap, i.e., an additional R of about 0.6?

I think part of the idea is (a) much higher efficiency (b) ease of installation/space needed. I do have the option of getting a reversible heat pump, but it would be a very bulky Stiebel Eltron that would take up most of my storage space; it would make what is now a garage into a small and inconvenient bike shed. But yes, my concern is whether adiabatic cooling will be enough, with heat waves such as the coming one becoming more frequent. Of course I'm also installing high-grade outside shades and the like.

Right - I was translating the French term PIV. My architect has some ad hoc solution for heat recovery (if I understood correctly).

I'm using the French term - there's most likely a different technical term in English. Fans are located so that air is sucked into the building, filtered, and, depending on the season, possibly heated or (as we are discussing now) cooled.

We are carrying out a renovation of (most of) a (small) house from 1930 in the Paris area. We (meaning really: the architect and I) will install MVHR by insufflation (i.e., the reverse of the usual direction). One possibility is to install adiabatic cooling (either now or later) - apparently it goes well with this sort of ventilation system. It would be nice to hear about other people's experiences with adiabatic cooling. Is it appropriate to the local climate? Paris is within the same broad climate zone as all of England (Cfb); compared to (say) London, its summers are hotter (by about 2C) and slightly more humid. hideClimate data for Paris (Parc Montsouris), elevation: 75 m (246 ft), 1991–2020 normals, extremes 1872–present Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year Record high °C (°F) 16.1 (61.0) 21.4 (70.5) 26.0 (78.8) 30.2 (86.4) 34.8 (94.6) 37.6 (99.7) 42.6 (108.7) 39.5 (103.1) 36.2 (97.2) 28.9 (84.0) 21.6 (70.9) 17.1 (62.8) 42.6 (108.7) Average high °C (°F) 7.6 (45.7) 8.8 (47.8) 12.8 (55.0) 16.6 (61.9) 20.2 (68.4) 23.4 (74.1) 25.7 (78.3) 25.6 (78.1) 21.5 (70.7) 16.5 (61.7) 11.1 (52.0) 8.0 (46.4) 16.5 (61.7) Daily mean °C (°F) 5.4 (41.7) 6.0 (42.8) 9.2 (48.6) 12.2 (54.0) 15.6 (60.1) 18.8 (65.8) 20.9 (69.6) 20.8 (69.4) 17.2 (63.0) 13.2 (55.8) 8.7 (47.7) 5.9 (42.6) 12.8 (55.0) Average low °C (°F) 3.2 (37.8) 3.3 (37.9) 5.6 (42.1) 7.9 (46.2) 11.1 (52.0) 14.2 (57.6) 16.2 (61.2) 16.0 (60.8) 13.0 (55.4) 9.9 (49.8) 6.2 (43.2) 3.8 (38.8) 9.2 (48.6) Record low °C (°F) −14.6 (5.7) −14.7 (5.5) −9.1 (15.6) −3.5 (25.7) −0.1 (31.8) 3.1 (37.6) 6.0 (42.8) 6.3 (43.3) 1.8 (35.2) −3.8 (25.2) −14.0 (6.8) −23.9 (−11.0) −23.9 (−11.0) Average precipitation mm (inches) 47.6 (1.87) 41.8 (1.65) 45.2 (1.78) 45.8 (1.80) 69.0 (2.72) 51.3 (2.02) 59.4 (2.34) 58.0 (2.28) 44.7 (1.76) 55.2 (2.17) 54.3 (2.14) 62.0 (2.44) 634.3 (24.97) Average precipitation days (≥ 1.0 mm) 9.9 9.1 9.5 8.6 9.2 8.3 7.4 8.1 7.5 9.5 10.4 11.4 108.9 Average snowy days 3.0 3.9 1.6 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.7 2.1 11.9 Average relative humidity (%) 83 78 73 69 70 69 68 71 76 82 84 84 76 Mean monthly sunshine hours 59.0 83.7 134.9 177.3 201.0 203.5 222.4 215.3 174.7 118.6 69.8 56.9 1,717 Average ultraviolet index 1 2 3 4 6 7 7 6 4 3 1 1 4 Source 1: Meteo France (snow days 1981–2010),[110] Infoclimat.fr (relative humidity 1961–1990)[111] Source 2: Weather Atlas (percent sunshine and UV Index)[112] These are 1990-2020 averages; of course things are getting warmer everywhere. Enjoy the coming heat wave!