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We changed our roof and cut CO2 emissions
- jopsen 5y agoInsolation is an extremely effective way to save energy. But with cold bridges and such it can be a little complicated to get right.
- _Microft 5y agoThat's insulation but insolation can also help with saving energy ;)
- codeduck 5y agoI'm guessing `insolation` turns you into a clean energy source. Can't imagine it's good for the immediate surroundings though.
- labster 5y agoNah, insolation is fine, so long as you keep it below 1362 W/m2 or so.
- dotancohen 5y agoEither GP poster is very, very tall (and can't breathe up there), or he's probably getting only about 300 W/m2 or so.
- labster 5y agoAt that level he could be on Mars near the equator, and it’s hard to breathe there, too.
- dotancohen 5y agoInteresting, so Mars' surface level insolation is similar to Earth's surface-level insolation, due to having less atmosphere? That makes solar power - and the Sabatier process - seem more feasible that I initially thought. I understand that Martian orbiters do require much larger solar panels than terrestrial scientific satellites with similar sensor packages.
- labster 5y agoI was researching before posting and I think I saw something like 40% in a paper, which is much more than the naive 25% you’d get at 2au. But for things like heating, latitude makes a big difference. I did some calculations for a fanfic I wrote, and at a moderate 30°N or so, you basically get the same insolation as Rovaniemi in Finland assuming similar atmospheres. No wonder those characters never got sunburns.
- bottled_poe 5y agoStill better than immolation.
- dotancohen 5y agoYet my ex would rank innoculation as even worse.
- bregma 5y agoSet a man a fire and he's warm for a day. Set a man afire and he's warm for the rest of his life.
- nicoburns 5y ago> Can't imagine it's good for the immediate surroundings though. Not sure about that. Plants absolutely love insolation!
- HPsquared 5y agoIf you have enough insulation, all you need is insolation.
- nraynaud 5y agoDid I miss the amortization of the CO2 emitted during the change?
- omgitsabird 5y agoTo preface, I am not trying to nitpick here. I am generally curious. Is this a correct usage of amortization? https://www.merriam-webster.com/dictionary/amortization https://www.merriam-webster.com/dictionary/amortization
- nraynaud 5y agoI don’t know, I’m not a native English speaker. I meant that: “to gradually reduce or write off the cost or value of (something, such as an asset)”
- heckerhut 5y agoAmortize is more than that imho. It’s about making a margin too.
- d8c6c050cb0a4d7 5y ago
- habibur 5y ago1.5 tons in 6 months. this period is important. otherwise number doesn't mean much to me.
- ClumsyPilot 5y agoThe annual carbon budget of each person is about 3 tons per person. Thats the amount planet's biosphere can process divided by number of peoplle.
- DoingIsLearning 5y ago> annual carbon budget of each person is about 3 tons per person To put that stat in perspective, the average carbon emmisions per person [0]: Qatar is almost 40 tonnes pp United States, Canada, Australia is about 15 tonnes pp Switzerland, France, Italy, under 5 tonnes pp South Sudan is about 0.13 tonnes. It really puts in perspective how much wasteful carbon reduction and lifestyle changes are needed for us to have any reasonable expectation at curbing this. Edit: added source [0] https://ourworldindata.org/grapher/co-emissions-per-capita https://ourworldindata.org/grapher/co-emissions-per-capita
- scrollaway 5y agoRemember that these figures include indirect emissions such as the ones made by the government on your behalf to maintain, for example, carbon expensive infrastructure. The roads are a big part of that in the US. American suburban car dependency needs to die.
- DoingIsLearning 5y agoThis may sound intuitive but is actually wrong. [0] All construction activities including roads, account for about 10.6% of emissions. For comparison energy use inside buildings accounts for 17.5% of emissions. Transport emissions (Land, Air, water) account for 16.2%. There are absolutely lifestyle choices at play here: Size of houses, size of car engines, car tonnage, commute distances, Travelling/Shopping habits. We cannot change minds and infrastructure overnight, the second best thing we can do at a policy level is to (magically) find ways for our energy production to not depend on coal/natural gas. [0] https://ourworldindata.org/emissions-by-sector https://ourworldindata.org/emissions-by-sector
- sgt 5y agoThey may be saving energy, but 17.2°C average temperature indoors is freezing.
- cameronh90 5y agoAverage UK indoor temperature is about 17.5c-18c apparently so hardly freezing. A bit chillier than I like in my office. Personally in winter I heat my house to 14c as a minimum, 20c in the living room and office. Reason being I only need warmth if I'm sat down and not moving, so any higher and I start to get too hot.
- jb1991 5y agoNo it’s not. That’s a very normal temperature for our bedroom in the winter time. It probably depends where you’re from, in colder climates people are used to it.
- sgt 5y agoYeah but this was the entire flat, right? A cold bedroom is nice, but not trying to type on a keyboard in 17C.
- balfirevic 5y agoSome people seem to like cold bedrooms, but it's far from universal. I try to keep mine around 27C in the winter (at the bed level, as measured by a small digital thermometer), and I still have to cover myself with a blanket (although a relatively thin one). Now I'm wondering how the comfort varies with the temperature of the walls (due to infrared radiation), which are obviously much colder in the winter than in the summer.
- empiricus 5y agoIt would have been interesting to also estimate how much CO2 would be reduced if instead of a glass roof they used a normal properly insulated roof. So we can see what is the CO2 cost of a stylish glass roof. Note: I suggest using underfloor heating, it should be more efficient with a glass roof, because there is less hot air to raise to the top of the house.
- onion2k 5y agoIt would have been interesting to also estimate how much CO2 would be reduced if instead of a glass roof they used a normal properly insulated roof. Buildings like this in Paris are often so tightly packed together that windows in walls barely provide any light. Replacing the roof with a more standard one would necessitate giving up any daylight and having lights on all the time.
- cbg0 5y agoWhy would there be less hot air if you set the same indoor temperature? Hot air will rise no matter what.
- empiricus 5y agoThe interesting part of underfloor heating is that it is not the hot air that warms the room. It is the radiation from the floor. Smth like 10w/C/m2. And the heat profile in the room looks much better. For example https://www.researchgate.net/figure/An-example-of-vertical-temperature-distribution-for-underfloor-heating-and-for-radiator_fig2_241169861 https://www.researchgate.net/figure/An-example-of-vertical-t...
- cbg0 5y agoWell, the infrared heating warms the air which warms the room if you want to be pedantic. Unless you're losing heat through the floor I doubt that temperature difference between the floor and ceiling is accurate with a radiator system, perhaps if you measure it 30 minutes after you turn on the heat, but throughout the day the temperature should be mostly consistent throughout the room unless you're losing heat through the floor.
- KaiserPro 5y agoOne thing to point out is that yes, saving CO2 is grand, but this doesn't sell just how much more _comfortable_ decent insulation makes things. I live in a '30s UK semi detached. It had an air brick , a blocked up fire place and blown double glazing in each room. (barring two that were replaced) We had to re-render the place, as it was starting to fall off at the front, and the back was scarred from unfinished renovations. We replaced the double glazing with triple (it was cheaper than double glazing at the time, so a no brainer. has a u-value of about 1.0) We also put 90mm of external wall insulation round the outside as part of the re-render. This cost an extra £4k compared to just a normal re-render. before the insulation, in summer the front room would reach 37 degrees C with the blinds down, and in winter with a 5kw wood burner and central heating on full we'd reach about 18 degrees c when outside was either windy or -3c Now in summer the hottest we've had it is about 29, with the blinds open. In winter we reach 20 within 30 minutes of the heating coming on. ( no need for the wood burner)
- dghughes 5y agoI wish I had done that to my father's home last year when he was alive. I didn't realize how much heat can come into a home from the attic. The joists act as a heat bridge radiating heat down from the ceiling. I plan on installing fibre wool in two layers one in joist cavities and one perpendicular over the exposed wood frame. My parents also have a door to the attic for storage and heat leaks up through the un-insulated edge of the pull-down stairs door. On YouTube Matt Risinger is a great resource for home repair and information. He tends to like expensive products but overall he explains main concepts well.
- specialist 5y agoAm a huge fan of Risinger. Early on, Risinger did a bunch "building science" explainer videos. Challenging then conventional building practices. Like advanced framing (using 2x6 studs at 24" spacing). Like properly insulate attics to prevent condensation and heat loss (keep HVAC vents within the thermal envelope). Those early explainers are the foundation (harhar) of subsequent product and project highlights. Alas, now they're hard to find (via YouTube's lame UX). Risinger should probably pin primers to the top of his playlist, linking into his archive. https://www.youtube.com/c/MattRisinger/videos https://www.youtube.com/c/MattRisinger/videos
- Kuinox 5y agonitpicking time :D > (assuming a 0.3g of CO2e per kWh It's kg there, not g. And this number is for the electricity, gas is 0.203 kg per kWh. If you are indeed heating with electricity, in france the electricity CO2 is almost always below 100g of CO2e per kWh.
- cbg0 5y agoIs triple glazing still not a thing in most places? It's become pretty much standard here in Romania in everything but the cheapest windows.
- teruakohatu 5y agoIn New Zealand it is available but I have never seen a house with it. Double glazing is the required minimum for new houses and has been for 20 years, but I would say at least half the country is single glazed.
- sersi 5y agoI wish! In Asia, single-pane/single-glazed is pretty much the standard. Even in 3600 usd/month apartments in Hong Kong, it's very unlikely you'll see double glazing. It drives me up the wall, winters are not long and it doesn't get that cold but there's a few days a year when the weather drops to around 12 degrees celcius within my apartment (so 54 degrees Fahrenheit) and as someone from colder climes that's used to central heating, I'll say that I much prefer a cold winter with a warm home than a mild winter with a super cold home. I've seen the same when I lived in Japan... Additionally due to the poor insulation, you get to hear the noise outside quite a bit which I personally hate.
- CorrectHorseBat 5y agoAnd it also helps with the heat in summer
- toyg 5y agoIn UK double-glazing is basically everywhere, with triple typically replacing it as windows fail. However, there is still a significant amount of single-glazed properties in poorer areas or in listed historical buildings.
- lbriner 5y agoYeah, Councils can be really bad at requiring people to either replace their old single-glazing with some exactly the same in double-glazed or keep the old inefficient windows. This is understandable for historical buildings but we experienced it with a box office building built in the 1970s, cost us another £11K to get cream coloured uPVC windows instead of white ones. I think that might change as we go towards energy efficiency, we need to swing the needle back towards more efficiency = good.
- bromley 5y agoNice savings! Tho no ingenuity is needed to calculate them as there is actually an established process used in the energy saving business. It uses "degree days" that are derived from temperature measurements, rather than using temperature measurements directly. Degree days work better in regression as, assuming the correct base temperature is chosen/calculated, heating degree days are directly proportional to heating energy consumption (including being zero when it is warm enough that no heating is needed) and cooling degree days are directly proportional to cooling energy consumption. More info and data here: https://www.degreedays.net https://www.degreedays.net including an article explaining the process typically used for before/after calculations: https://www.degreedays.net/calculate-energy-savings https://www.degreedays.net/calculate-energy-savings Disclaimer: I work for the company behind that site, and yeah I know it looks a bit dated :D
- bromley 5y agoI'll just add a little more explanation here since our site goes pretty in depth and I imagine most here would only be interested in a brief overview: So buildings have what is known as a heating base temperature, which is the outside temperature above which heating is not needed inside the building. This is not the thermostat temperature inside the building (say 20 C), it is actually lower because of various factors like people and electrical equipment generating "free heat" inside the building, and how well the building is insulated to retain that free heat. The base temperature varies from building to building, but let's say, for example, a fairly-well-insulated home might have a heating base temperature of 14 C. If the temperature outside is 14 C or above, that building will stay perfectly warm inside on its own, without the heating system needing to come on. But, if the outside temperature drops below 14 C the building will need some heating to keep it comfortable inside. How much heating it needs will depend on how much the temperature drops below 14 C, and for how long. And this is what heating degree days quantify. Here is an example diagram that demonstrates quite nicely how they are calculated (using a base temperature of 14 C): https://www.degreedays.net/images/heating-degree-days-calculation.png https://www.degreedays.net/images/heating-degree-days-calcul... The neat thing is that the heating degree days for any period of time represent all the relevant temperature variations across that period of time, and assuming you used an appropriate base temperature, are proportional to the heating energy consumption over that period of time. So for example you can have just one figure that represents the heating degree days across an entire week/month/year, and that will encapsulate all the relevant temperature variations across that week/month/year. If January had 200 heating degree days, and February had 300, you can expect the heating energy consumption of the building to be 50% greater in February than in January. (Assuming you have chosen the right base temperature for your building that is!) Compare this with knowing that the average temperature across a week/month/year was 12 C. What does that tell you about how much heating was needed in that week/month/year? Not a lot, cos you have no idea how much it varied within that time. This is the case even within a single day, since the temperature can vary a lot within a day. Hence why people in the energy-saving business would typically use degree days rather than temperature data :) (That said, hourly temperature data or similar is good for more sophisticated building simulations. But those are a lot more involved. On the simpler end of the spectrum degree days are a much better choice.)
- dghughes 5y agoOne thing people are not so much aware about other than insulation is air sealing. A tiny gap that may seem like nothing is in fact very bad. Take windows notoriously bad for heat and air leaks. A small seam along a window that isn't locked (it should be) could be the equivalent of having a 1cm hole in the wall. If insulated well and air sealed a home would lose very little energy. But also you'd need a good air handling system to move and refresh the air.
- kleiba 5y agoThat's right. The other day I drove by a house that's currently undergoing renovation, but the guy who owns the house does everything himself in a jack-of-all-trades kind of manner. He had put on a nice thick layer of insulation on the outside, but the sheets/blocks were apparently too short in some parts or simply fitted poorly, and in other areas I saw that he had just used some left-over cut-offs of various shapes and sizes in what looked almost like a mosaic. To make everything stick and fit, tons of sprayfoam has been used in an attempt to fill the inevitable large gaps (1 inch) between the blocks. I kinda feel sorry for the guy, investing all the hard work and having good intentions, but due to poor workman ship he cannot expect to get the insulating effects he's surely hoping for.
- lbriner 5y ago> But also you'd need a good air handling system to move and refresh the air. And therein is the rub! Ventilation is critical in building design and many older houses cannot easily be retrofitted with a mechanical ventilation system, not to mention the costs. Also, sealing air gaps is pretty much impossible in a house that wasn't built this way. I have been trying all kinds of things in my (30 year old) house to seal up gaps but there are spaces inside the floors to the outside through small mortar gaps, spaces behind electrical sockets, gaps in various parts of the floor and even around windows between the finishing. I would personally like to see a more top-level view from governments. In the UK, for instance, they should be targetting the oldest housing stock and simply replacing it. I know this is hard because people own their freeholds but if we are serious and if someone would get a nice warm house in return for their old house then I think most people would be up for it.
- aaron695 5y ago
- Glench 5y agoThis is great. I'd also like to point out that with switching from gas to heat pump heating/cooling you'd probably save even more on your bills and have 0 on-site carbon emissions and likely 0 off-site emissions as your electricity starts coming from non-carbon sources. Heat pumps are around 3x more efficient than the most efficient gas heating because they're just moving heat around, not creating heat. As Saul Griffith says[0], "You can't 'efficiency' your way to 0" (meaning 0 emissions, which is what we need). Efficiency is a great win for our bills and cutting some emissions but even if every building made their current systems more efficient, we'd still be on track for over 1.5C of warming. What we need is transformation, and most of that to electric heating/cooling/transport/cooking. And we need it fast, all across the residential and commercial economies in the next 2 decades with more in the next decade. It's going to be a war-time-like effort. Thanks for getting it started! [0] https://mitpress.mit.edu/books/electrify https://mitpress.mit.edu/books/electrify
- robomartin 5y agoInteresting. It would have been nice to add a calculation of the energy required and CO2 produced to manufacture, transport and install that roof. I feel this is an important metric that is generally ignored in these conversations. And yet, it is crucially important in order to determine the true outcome. That said, I understand just how complex this input can be to obtain. You can’t reduce it to a number per window. That’s not how it works. In order for someone to produce those ten (or whatever) windows somewhere in the order of twenty companies must exist and operate constantly. Aluminum mining and processing, steel production, extruders, paint/coatings, chemicals, oil/petroleum, fasteners, cardboard and foam packaging, forklifts, trucks, CNC machines, computers, etc. The point is: These companies don’t exist just for the 42.5 minutes it took to assemble and pack the windows. In order to be able to buy ten windows, they have to exist whether or not someone is buying that model window or not. The energy required and CO2 produced comes from the combination of all of these factors. And, yes, this is hard to estimate. Yet the numbers are very far from zero. It’s like saying you are going to go live in a tent on a small island to reduce CO2 emissions while ignoring the car ride, flight and ferry that get you there and the freighter that delivered your possessions.