Last summer I lived in the largest passive house settlement in the world, in Heidelberg, Germany, and the main complaint is the heat in the summer. Even with cooling down the apartment to 20°C with open windows all night, and closed windows and window blinds all day, the apartment would be back at 28°C when returning after work. Basically it is too hot in the apartment from May to September. In a survey nearly 60% of the people living there complained that it is too hot in summers, so it doesn't seem to be an isolated problem to the specific building I lived in.
Nighttime cooling only works if you have a big thermal mass inside the insulation envelope to cool down to store your 'coolth' in. In general the problem with lightweight stick frame construction is that it is too quick to respond to temperature changes so it not a good fit for this. Ideally you build off a big concrete slab which is sat on top of non compressible insulation. The houses on page 36 of this magazine use this technique.[0]
cooling down the apartment to 20°C with open windows all night
This sounds like mainly the air cooled down while a lot of heat was still trapped in the building itself. There are ways to make this better though. So you could say that particular building is not overly well designed. 28°C is just too much. Though no matter what you try, unless you're under ground, if you have 10 or more consecutive days with temperatures rising well over 30°C, you won't really be able to stop that. Anyway it's been a while I looked into this but some things I recall: a lot of mass on the roof, like a garden, will keep much of the heat out there. More mass in general as well IIRC becasue it just takes longer to heat (but again, once all heat is in and it's too much, you're going to have to wait before it is all gone again). Avoiding direct sunlight on the walls also helps. Reflecting glass, outer blinds (blinds inside doesn't do all that much, that's basically too late because sunlight has entered the interior already).
One more cool idea: setting translucent Phase Change Materials (PCM) directly against your windows. PCMs are wax-like material that have a high latent heat of fusion (energy it takes to change the phase of material i.e solid -> liquid). Because latent heat change occurs at a constant temperature, the PCM acts as a thermal storage when solar energy or ambient temperature increases, and then releases the heat during the evenings.
At my (architecture/research) office, my colleague coded a 3D FEM to model the way this interacts with different geometries so we could investigate how to regulate the thermal storage capacity of a PCM surface. I'm fascinated by PCMs, although he seems to think that the resulting temperature dampening is too little[1] to have broad application in architecture...
[1] Liquid -> gas phase change has a higher latent heat of fusion and might be a way to solve this I think. It would require larger volumes, or a way to safely contain higher pressure, but similar to fridge or AC systems, this should provide a couple of orders of magnitude greater heat storage.
ICF (Insulated Concrete Form) construction takes this approach tempering the indoor temperature. My brother just moved into a brand new ICF house in Salt Lake City (relatively cold winters and hot summers) and it is remarkably efficient.
I’m not totally up on my passive house knowledge but it seems to me that the passive house community might have some complaints about this block of pretty conventional looking apartments calling themselves passive houses. I see no effort at all in controlling summer thermal gain [except for some extremely narrow solar awnings]. Are they using special window coatings?
Edit: and my god, all of the floor to ceiling windows in their publicity shots are on a street that faces southwest. Of course it’s gonna be hot in the summer. And those trees won’t solve the problem for thirty years.
Yeah, any heat that comes in through the windows in the form of sunlight stays in a passive house. You need effective awnings, otherwise you are doing something silly.
Controlling the sunlight is important, but it's important to remember that the outdoor ambient temperature, and interior heat gains from occupants and equipment will play a large role in interior temperature - especially in larger buildings that tend to have a low surface to area ratio.
And in that case it's not just about controlling the solar energy that's coming in, but also having an actual cooling strategy, like natural ventilation, or night cooling.
I saw some construction pictures of this site that make it look like the windows are a sun-porch style arrangement, not unlike a typical passivhaus design. From the artist drawings it just looks like a stereotypical modern glass midrise.
But there's something still off about it. I'm not sure what I expect a multifamily unit to look like but the fact that this one gets complaints of being too hot doesn't surprise me.
I live in the Heidelberg/Mannheim area of Germany and this problem is most definitely not restricted to passive houses.
I know several people with top floor apartments that regularly come home to 32°C apartments after work in the summer. Summers here are hot with little air movement and even sleeping with open windows it's impossible to get it cooled down in the night.
If I didn't live in a rental place I would definitely invest in air conditioning.
AC is generally not a thing at all in German residential properties. Usually only in stores/offices/etc and even then it's not a given, I once worked here in an office with no AC. That was a hard summer and it was horrible trying to concentrate on work.
As I think someone else mentioned European/German windows are different to American ones. American ones, lift from the bottom up I believe and an AC unit is put in the gap. European windows can be tilted to be slightly open, or completely opened up into the room much like a door [1].
There are Window units I believe but the Windows have to be modified for them I think, so it's more of a permanent change.
There are also freestanding units which have a hose to go out a window but I've been told from several people that they're not worth the money / don't cool the place down enough. And because the window has to be slightly open for the hose to aim out of more heat keeps coming back in.
AC is not really a thing in private homes almost anywhere in Europe.
Windows also work differently here in Germany than in the US, so the same models definitely wouldn't work. I'm not sure if there are versions for our windows.
Pretty normal in Norway, just reversed. But I’ve never seen the window version. Usually the a/c unit is mounted on the outside wall and a hole is drilled in the wall to bring in the hose to the unit inside.
> AC is not really a thing in private homes almost anywhere in Europe.
Northern Europe, no; but in Italy they're now very, very common. Temperatures there are steadily rising. Italians used to mock countries where AC has long been de rigueur (North-Africa, South-East Asia etc), but now it's a basic necessity - in areas that already felt very hot because of high humidity, they now hit 50°C year after year.
I found it interesting that the new Apple HQ (space donut) won't have any are air conditioning. I find it hard to think that a string of sunny hot days won't spike the temp to uncomfortable levels.
Seems like there was too much glazing (windows and doors) on the south side. It's a problem that a lot of glass skyscrapers face right now as well. They have so much solar heat gain that the AC will be running on a warm spring day just to stop the inside from getting hot.
San Francisco has a number of “luxury” skyscrapers without AC. While this might make sense at ground level, the combination of height, so much glass, and windows that barely open makes things pretty uncomfortable without it.
>Even with cooling down the apartment to 20°C with open windows all night, and closed windows and window blinds all day, the apartment would be back at 28°C when returning after work.
what was the outside temperature? I live in a fairly normal, cheaply-built and poorly-insulated canadian house without AC and in order for my house to get up to 28C by the end of the day it's got to be about 35C outside. It seems hard to believe that a building specifically designed to be "passive" could perform worse.
Last year I lived in a older mobile home in Saskatchewan (tin clad, all south-facing windows). It could definitely get up to around 28C during the day if I wasn't careful about managing things (open the windows while it was cool in the morning, close them by 10am or so, make sure shades are drawn, etc). I only had a wall-mount AC unit, and if I messed up the heat management process I had to run the crap out of it to get the temperatures back down to something manageable.
Fortunately I was working from home, so I would catch a screw-up early (when I'd realize that I was starting to sweat because of the temperature).
Winter was interesting too. The trailer wasn't all that well insulated, so the furnace had to run a fair bit. But on sunny days, even in the middle of winter, you could really feel how much the sun contributed to warming the place up.
It was an experience that really drove home the concept of solar gain though! If I were still living there, I'd be putting up carefully angled awnings to reflect the sun during the summer but still let it in during the winter (when it's lower in the sky).
That is interesting. I've had to run building energy simulations where I spent a lot of time running through similar scenarios while trying to figure out set points for an automated natural ventilation system. It went pretty much exactly as you describe, if you don't catch that heat gain at the right moment, the interior temperatures can get caught increase to a point where opening windows won't exhaust the heat anymore. Since I was working on a completely passively ventilated building at the time, that meant the heat gain would remain, and if there would be a gradual positive feedback loop over the course of a couple of days meaning everyday the interior temperature would get a hotter.
On hindsight, I wish I'd tracked the data for you :)
We were fortunate enough last year to still have quite cool nights; even if I screwed it up, opening the windows at both ends of the house would cool the place down quite well over night. The only really awkward part was when my wife would come home at 6pm, and she'd be uncomfortably warm until it got dark (which wasn't until 10:30pm or so).
Vancouver climate is a lot more temperate than most places in the world. It rarely goes below zero, and during the few months of summer, it will rarely go above 27 C. Most houses don't even have AC so passive houses seem like a great idea.
im sorry but this means that the houses were not designed well. if you have a house that is well insulated, and that does not leak heat from the ventilation system, that means that it will stay the same temperature. if you go through a cycle of cooling and then coming home to a hot house and then cooling again, eventually you will stop coming back to a hot house. the only explanation is that there is a leak (poor design) or that heat is being injected into the house through sunlight or some other means. i would put my money on sunlight making its ways through poorly implemented windows.
by the laws of physics, if you have a passive house kind of house, you will not be able to come home to a hot house repeatedly.
It kind of sounds like GP's was just a regular house, opening windows etc. at night and closing everything during the day is what I do with my regular house. I'd expect a passive house to handle a lot more of this without requiring those types of interventions, and be a lot more successful at it. Like...I don't think something qualifies as a passive house if it doesn't work.
Probably a design with south facing windows simply because while 28 degrees is unacceptable, so is an architecture with no windows in one or more directions.
Also, all power used inside the building must be dissipated somewhere. In a very well insulated building even just 500W idle power inside quickly adds to the air temp.
first of all, a house with no windows on a single side is not unacceptable. i live in a place that only has windows on one wall and i find it more than acceptable. look at all the houses that people have built with no windows on one or more faces. there are innumerable examples that prove you wrong. and on top of all that, its a completely subjective thing, whether a house needs a certain number of windows. you cant just say that leaving out windows on one side is objectively and definitively unacceptable. thats bullshit.
furthermore, there is no need to omit windows on any side, even the south side. typically, a shading structure is placed that blocks direct sunlight during the warm seasons when the sun occupies those seasonal positions in the sky. these shading structures do allow sunlight when the sun is in its cold season positions, when sunlight is appreciated inside. going even further, windows should filter out any light that is not within the useful spectrum of visibility -- this reduces heat load from the sun. movable shading can also be used to block the sun only during the warm season.
there are countless examples of houses that have lots of windows and do not get too hot.
moving on to power. the back-side of your refrigerator should be vented, not exposed to your inside environment. led bulbs produce very little heat. overall, as i have said elsewhere, you will always need some amount of cooling and heating capacity.
it remains true that a properly implemented passive house will not get too hot, despite your shortsighted observations.
I have almost no windows on the North/East because the idea is to maximize light and have as little heat loss through the windows as possible (heating here is far more expensive I’ve the year than cooling).
In hot and stable climates it’s probably common to not have large windows to the south, but in places where you have +30C in summer and freezing to -20 and dark all winter it’s hard to architect for all seasons. I wouldn’t give up the 4h daylight in my south windows in winter, even though they make the house too hot in summer. Shading that can be removed is probably the answer.
Vented rears for freezers, how does that work? Do they typically sit in an outer wall, or do they have ducts venting so they can be placed anywhere? I have never heard of those.
venting appliances that create heat is not done anywhere as far as i know. the refrigerator is the main appliance that needs this because it is essentially a heat pump that runs all the time. insulating it well and venting its hot side is very simple conceptually and is completely doable.
not venting heat generating appliances inside the house is a design flaw and does not follow passive house principles. because nobody addresses this problem, i do consider almost all passive houses to be incorrectly designed and implemented.
the reason why this problem is not addressed is because some degree of cooling capacity is usually present and can keep the house cool despite this flaw. the heat load from the appliances is relatively small and so it is overlooked -- small compared the loads encountered in old-style houses. also, heat generating appliances are a benefit during the winter, so the problem only exists half of the time.
in an ideal system, all heat generated by all systems in and around the house would be channeled and utilized correctly. we are coming closer to that goal.
no, this is not the point of passive houses. it is a contradiction, but the point is to reduce hvac use as much as possible. you will always need hvac for perfect results because it is impossible to build a perfect hrv system. its impossible to insulate perfectly. there will always be heat leaking from the system. in some extreme cases people can do away with their hvac completely but its difficult and expensive.
Living in Austria we have very strict building regulations and a lot of insulation and despite of this there are more and more air conditioners because it’s so hot outside in summers now that even nights are too hot. No insulation in the world can fix that, especially if heat is also created inside.
Spaniard here. While not ubiquitous, household AC is not even rare nowadays.
It depends a lot on the area though: it's uncommon in the north/west (where temperatures get pretty low during the night even during the summer), but not in the south/east where temps won't go below 25ºC for several days (and nights) in a row.
My previous startup was an API that would give homes an energy efficiency letter grade along with a bill estimate to embedded in real estate websites. While it failed for a host of issues, one that stood out in my head was how little people valued efficiency over renewables.
Generally speaking, money invested in improving building efficiency will have a better carbon and financial payback than any form of solar, wind, or hydro. And yet, homeowners will get solar panels before they insulate their walls.
It's often more pleasant to have more passive heating than more insulation. I prefer a reasonably well insulated house, that leaks a little air vs an insanely insulted house that's practically air tight.
Passive solar / solar hot water heaters let you have the best of both worlds with ~zero monthly heating costs and plenty of fresh air.
> Passive solar / solar hot water heaters let you have the best of both worlds with ~zero monthly heating costs and plenty of fresh air.
Depends on where you live I suppose.
I was talking with my landlord a couple weeks ago about solar water heating (surprisingly rare in Arizona being the desert and all) and he said he looked into it before but it would cost more than gas due to all the bureaucratic hurdles put in the way -- which explains the rarity I guess.
It's much cheaper and easier to install when building a house then add on after the fact. Which I suspect is a large part of the issue as people don't generally consider utility bills when buying a home, and the home builder does not realize the savings.
Was this an American centric startup? I know in especially Germany and probably much of Europe building efficiency is a big deal, to the extent that things like smaller windows are prioritized.
From the article's description, apparently "Passive House" means "no cooling whatsoever", which explains why it's not common in the US.
Don't get me wrong, we need stronger building standards and better insulation. Especially in the US, where we let literally any hollow twig+glue structure stand with essentially no quality checks whatsoever.
But the reason everyone "throws a solar panel on top to get Net Zero", is because it gives you cheap green electricity to run both heat and Air Conditioning. There are precious few places you could build this thing in the US where it won't be annoyingly hot to live in for at least 3+ months every year. Even in Michigan, a building is essentially broken if it doesn't have AC, if not for the heat then to at least remove the moisture / humidity / condensation built up.
You don't need AC to remove humidity. MVHR removes it and dumps it into the drains when the warm outgoing air goes through the air to air heat exchanger to warm up the incoming air.
Warming incoming air is the opposite of what people in the US mean by "air conditioning". It seems to me that what you are describing is the opposite of how thermodynamics works. Warm air holds more moisture and condensation occurs when air is cooled below the dew point.
I was responding to the point about using AC all year to remove humidity. The thermodynamics works like this: The air inside your house is more humid than the air outside; warm air at the same pressure holds more moisture than cold air. When you extract the warm air from the house the heat exchanger cools it down, therefore reducing its moisture carrying capacity and causing condensate to form which you can remove. The heat is transferred to the incoming cold air via the heat exchanger, the warmed up incoming air now has a much greater water carrying capacity even if it was already humid outside so it absorbs humidity from your house, when this air is extracted again the cycle repeats. Passive houses have very low humidity inside because of this.
> I was responding to the point about using AC all year to remove humidity.
That's not something I claimed.
Most people in the US are only using AC in the summer (or warm season), to remove humidity from their home when the humidity outside is much higher than indoors.
Sorry I was confused when you said “if not for the heat then to at least remove the moisture”. When your insulation is being used to keep heat out, your heat exchanger would operate in reverse to use extract air to cool incoming air, some MVHR units have optional precooling of incoming air. I expect a modern standard AC unit will be doing some cold recovery as well to improve efficiency. But ideally a fabric first approach will keep a lot of heat out when combined with external blinds and brise soliel to keep high angle summer sun out.
Then where does the heat from your dehumidifier go?
MVHR seems to assume outside air is always cooler and fresher than inside air, and uses that for free cooling. Which is great for like 70% of the time. But what about the ~30% of time when it isn't there.
If you don't have a dehumidifier, all of those big bags of mostly water that inhabit the building will expel some of that water with every breath, and going to increase the humidity fairly noticeably.
I'm also going to guess that the MVHR is also not 100% efficient. It's either going to create heat to completely cool down the incoming air (hey, look, an AC, complete with dehumidification), or the incoming air is going to average out with the out going air, creating an increase in temperature.
Plus, all of those bags of mostly water are going to be expelling heat, too.
what are you talking about? who mentioned a dehumidifier? mvhr simply exchanges air without changing its temperature. its not great for cooling or heating by its very definition. its good for humidity and freshness. using insulation and hr ventilation simply allows you to have a heating and air conditioning solution that is massively reduced in size. in some cases none at all.
> From the article's description, apparently "Passive House" means "no cooling whatsoever", which explains why it's not common in the US.
That's not what Passivhaus is.
A cooling requirement, like a heating requirement, is dependent on the performance of the house. Part of Passivhaus is the 'fabric first' approach which delivers performance which massively lowers this requirement, in some cases eliminating it.
As already posted, ventilation solves the IAQ problem.
you dont seem to have read the article. passive houses generally have very good insulation, very air-tight envelopes and a system that is called heat recovery ventilation.
insulation and air tightness afford the house the property of staying the same temperature on the inside regardless of the temperature on the outside, more or less. if its too hot or too cold outside, this is something you always want. heat recovery ventilation gives the house the ability to move old air out of the building and new air into the building while not changing the temperature of the air inside, more or less. this is why its called heat recovery (also it could also be called cold recovery). this solves humidity problems.
the end result is a house that will tend to stay the same temperature, whether that is hot or cold. in an ideal model of this kind of house, you can see that heating and cooling costs are reduced to almost nothing because you simply choose a temperature that you like and simply never think about it again. this is the origin of the "passive" component of "passive house." with a passive house, you simply dont need a large hvac system. and there is nothing stopping you from adding a modest solar system to your passive house to get to net zero -- it is done quite frequently.
> insulation and air tightness afford the house the property of staying the same temperature on the inside regardless of the temperature on the outside, more or less.
But how is that initial temperature determined? If the house is built in a area during a time of year where the average air temperature is about 85F, then will the house always be too hot? How does it get cool (or hot) in first place?
the initial temperature, in that ideal system, is determined by deliberately making it hot or cold with a small sized air conditioner or heater. so in the ideal system you heat or cool once and then never again.
A common thing to do with a passive house is to put a bidirectional heat pump in the heat recovery ventilator. So you get cooling as well as efficient heating. With a passive house you only require a bit of either.
WARNING: Decreased Oxygen is a problem with well-sealed houses. I live in one.
You must have fresh air to avoid CO2 poisoning. If the outside air is a problem, then you either 1) give up on being passive and use conditioning of some form or you 2) begin the suffocation process (starts with poor concentration then moves to headaches).
This is one reason for NetZero as an alternative form of building. Even using a solar array with an HRV (Heat Recovery Ventilation) or ERV (Energy Recovery Ventilation) helps a lot if you don't want to run a full compressor-based system.
Is your house more sealed than a typical new home? I live in a new home with an HRV system (all new homes here have them), but I always assumed they were required for issues related to condensation and humidity, not oxygen levels.
My house is much more sealed than a typical new home. Every crack was sprayed with foam and every sheet of OSB/decking was taped, then the house was wrapped in ridge foam panels and taped again. Then it was wrapped in house wrap. The weep holes on the windows, and front door, and the venting for the stove and bathroom are the only source of outside air. There is no attic. http://tinyhousemansion.com/
Most homes leak plenty so HRV's are mostly about recovering costs and helping with condensation and humidity since they are designed for cold weather.
Oh! I watched your tiny home tour a while ago! Yes, I can see why your definition of a well sealed home is likely a lot different than what would be considered "well-sealed" for a typical new home, as well as why concerns about oxygen and CO2 are a factor.
I mentioned that HRV's are essentially standard where I live, which is in Canada, so I think our largest concern here has to do with condensation which can quickly become an issue in any non-drafty indoor space in our extremely cold winters. If the HRV is not set high enough in the winter, ice will build up on the inside of our windows and then melt into the wall structure, causing potential issues.
>The building is a simple super insulated “dumb building”. No technology or complicated mechanical systems, just a simple envelope, high quality windows and high quality air control through Heat Recovery Ventilation. Walk in and set your heat……that’s it! The money is spent on its simple well-built design, not technology.
That is rather sophisticated by North American standards for multi-family housing.
I was stunned when I first saw multi-family houses being built in American as a simple wooden, skeletal structure.
My choice for something like that would've been steel frame with thermal stops for non-load bearing walls, non-removable formwork out of something like MGO board, and foam concrete pour. Not much separate insulation required for this design.
Multi-family housing in America is for people with no other choice, i.e. students and the poor. The (re)emergency of “luxury” multi-family housing for quality-conscious middle class residents is recent, small-scale, and vehemently opposed by most. Even then, much of what’s marketed this way is the same as always, with better-looking countertops, appliances, and paint.
Only the very top end of multifamily rental housing is comparable in quality to ordinary single family homes. I have found high-rises to be more solid than mid-rises, probably because steel is a must.
You have to look at just how deeply our culture rejected cities and how deeply ingrained the American Dream of suburbia became.
I lived in a dormitory built that way, with double-pipe steam heat. We'd nearly all turn off our heaters in the winter; the ex-californians kept the building so warm that the rest of us opened windows to get down to a bearable temperature. Delightful experience, really.
I know of at least this Canadian company that specializes in single-family steel-framed design and construction, but it definitely is more on the high-end side of things.
I saw one of their projects going up in Saskatoon. It looked to be an in-fill two-suite house. It went together amazingly fast, and from what I could tell it was very well built. The Bone "system" they've put together is pretty cool too; all of the major pieces come on a truck pre-cut and then assembled on-site. It reminded me of Meccano.
Same in Vancouver. These can be built however and there are architecture firms and construction companies that will gladly take on these projects. The issue, of course, is that it's much cheaper and simpler to build from plywood.
Stay-in-place formwork is made as easy as erecting steel stud walls, and covering them with high grade MgO drywall of sufficient thickness and density (1.5cm D1.1). Chinese suppliers have plenty of that prefabricated with fitures. https://s.1688.com/company/company_search.htm?keywords=%C4%A...
One important thing: always ask for MgO board with MgSO4 binder. MgClOn ones can turn corrosive due to minute manufacturing procedure deviations.
2. You mix bubble generating chemical into concrete that will expand it after the pour.
It is a tricky and rather obscure tech mostly used across the former bloc countries or places that used to receive Soviet tech like India. Working with it is much more of a skill rather than science, and this hampers its adoption.
Biggest roadblocks other than skill intensity:
1. Corrosion protection - porous concrete is obviously more permeable than solid one. Easy ways to protect armature do not work as with solid concrete. Zinc anodized steel or other consumable protections will simply be consumed much earlier than in solid concrete, or worse, be eaten by lower PH of a foam concrete after settling. You have to put additional alkalinisers, or flyash, but they can destroy the foam. Finding a foam that will stand your alkaliniser, or a particular composition of flyash (flyash from different powerplants and blast furnaces can be dramatically different chemically and change in composition over time!) is always a challenge.
2. Faster hardening, especially with alkalinisers or geopolymer base - 40 MPa in just 2 days. You also have to spray formwork with water copiously to prevent it from premature drying.
3. Bigger sensitivity to chemical purity of components in general. Additives for foam concrete are an esoteric matter.
What I say about it: advantages worth the trouble
1. You can go down in density down to 350 per cube, or even 150 if you are a concrete chemistry magician. 350 gives you 0.1 W/mK thermal conductivity
2. Incomparably more flowable and pumpable.
3. You can use cements that are wholly geopolymer based or natural cements which is a huge economic incentive.
4. Can be used structurally above 600 per cube density with 13kg/cm2 load bearing capacity. Load bearing capacity goes up non-linearly. 850/cube already give you 30kg/cm2
5. Settled foam concrete is workable with just saws and hand tools. If you have to fix a screw up, it is much easier than with solid Portland cement.
Tangentially related anecdote: I remain convinced that it's the occupant, not the building that matters. I heat my uninsulated 1910 era flat for about ~150EUR/year. Of that 150 about 100 goes to hot water (showers, mostly). How? By wearing clothes in winter. Sometimes a blanket if it gets particularly cold. In winter my indoor air temperature is around 14°C, which is plenty when you're wearing clothes.
Buying extra insulation, or a "smart thermostat" or any other "energy saving" thingamajig would cost a lot more than the payoff would ever be.
Does everyone in the house do this or just you? Apartments are usually heated by neighboring apartments, which means even if you turn off your heating, the temperature won't drop too low unless your neighbors do it too.
I have neighbors who live this way near Boston, where it's often well below freezing. They wear a lot of wool. Bed curtains and sleeping hats come out in winter. It can be a perfectly pleasant way to live.
The lack of dollar signs on the thermostat leads many others to heat above, sometimes well above, 20 °C in winter.
I can only assume you live somewhere pretty warm - if I don't have the heaters on in my apartment, the indoor air temperature will be roughly equal to the outdoor air temperature, which is frequently <5°C in winter. No amount of clothing is going to make that comfortable or healthy to live in.
I don't know how much it costs to heat my place, since I only have storage heaters, so it all gets merged in with the rest of my electricity usage.
> the indoor air temperature will be roughly equal to the outdoor air temperature
Your insulation could definitely be improved - I live in Scotland and when it's 0C inside it seems to equalise at about 10C simply from having humans in with cooking and lighting. That's still a bit uncomfortably cold so I run the heating, but without good insulation a lot of paid for heat would be escaping.
Oh, no doubt. It's an old terraced house in London, and I'm in the basement flat. No double-glazing, and I doubt the walls are properly insulated. But it's relatively cheap, and running the storage heaters 24/7 hasn't resulted in an excruciating power bill.
The only time I've actually noticed it being brutally cold was coming home after several weeks abroad, where I'd turned the heaters off before I left to save power. Coming home after that was particularly unpleasant.
If you're interested in figuring out the costs, they sell devices —— called calorimeters i think -- which you can stick on the storage heaters and will make pretty decent estimates of the amount of energy released.
That’s thanks to your neighbours heating. 14C is too low - the walls must be colder than that, leading to condensation of water on the surface. Do you maybe have problems with mold on walls? That would definitely be a problem at a house due to higher humidity. It would get lot colder if you lived in a house.
Nope, that's the upside of a draughty old building, all the air leaks keep the place well ventilated and pretty dry. 14C is not too low, in fact it was pretty common before the age of central heating.
Additionally, I'm on the ground floor on a street corner, so three walls exposed to the air and one wall shared with a large garage —— which i assume isn't heated.
I have a stand-alone drafty New England farmhouse. That’s about my nighttime thermostat temperature. I go up about 3-4 degrees C during the day if I’m there.
Some of my family recently lived in Croatia, and were forced to do this in colder weather (closer to ~10° C median). They didn't care for it at all, since they had to remain constantly bundled up in their winter gear. Which, a jacket or heavier pants, OK... but gloves and hats too? Ugh.
14° C (just under 60° F for us yanks) is tolerable with sweats and movement, or even just direct sunlight, but you're living in a pretty temperate place if you can keep it there with an uninsulated building. Vancouver is not such a temperate place.
I think this is pretty much the way to go in terms of future housing - obviously, adapting to local climate and needs. I’m surprised that so many passive/ ecological houses are designed for single families, which must be a poor use of resources and land (in most places).
I wish I could increase the insulation capabilities of my house. My house is literally stucco on the outside, a paper vapor barrier, and then it's the studs and drywall of my walls. I have no sheathing in between my studs and drywall, so I have massive air flow. I would literally have to rip down all my walls and add a layer of sheathing in order to stop air flow and add insulation, and would cost ~$50,000. Better to just turn on my furnace during the winter months and spend $300/month for 4 months a year.
You can add dense pack cellulose insulation pretty easily to an uninsulated house. Home depot rents the machines to do it. Use a hole saw at the top of the drywall, shove in the blower tube and fill the cavity up with low cost cellulose.
Even though better energy efficiency is great, the video highlights how policy for efficient housing requires minimising draft, which implies convection heating. This means that (at least on this topic) policy is still not addressing the really fundamental problems. To give an analogy: we did not get the modern computer by building a better vacuum tube, we did it by switching to an entirely different technology.
Kris de Decker has written extensively on this topic: why convection heating is problematic, which alternatives exist, and the problems with focusing exclusively on energy efficiency[0][1][2][3]. In short:
- On a meta-level, the actual problem we are trying to solve is not one of heating. Heating is a solution. The problem we are solving is how to stay warm. Framing it this way opens up entirely new options to explore.
- Air is a natural insulator with low thermal capacity, so an incredibly inefficient transport medium of heat. When heating up a cold room, the ambient air may heat up quickly, but the objects in a room can stay cold for very long.
- Convection heating requires that the heated air does not escape the room, so we end up with a trade-off between heating and fresh air. Personal anecdote related to this: I live in house that is so well-insulated that I cannot sleep with the window closed, feeling exhausted and out of breath in the morning (likely more due to the rise of CO2 than a lack of oxygen, but the result is the same). These days I sleep with the window open, under three layers of blankets, and the heating to a bare minimum.
- Convection heating also heats up the entire space, which is really wasteful: we really only care about heating the humans and other living things inside this space. To point out how ridiculous this really is: hot air naturally rises to the ceiling first, where nobody needs it. (admittedly, when a space remains damp and cold for a very long period of time, there is the problem of mould to consider. There are solutions for that, and they are more sustainable than wasting heat with convection heating)
- Because the heat in the air is absorbed at the windows, we have to put the convection heater next to it to get an even heat gradient in the room. So in other words: we put our heat source right next to the biggest heat-sink in the room.
Other methods of staying warm, like radiant heating or electrically heated clothing (yes, this exists) can bypass most if not all of these issues.
The problem is that we are trying to make modern lifestyle more efficient without radically questioning the lifestyle itself.
Elizabeth Shove had a good paper on this problem, although it can get quite dense[4]. Kris de Decker has a more accessible summary of it[3]. I'll highlight some stuff from Shove's paper:
> Programmes of energy efficiency are politically uncontroversial precisely because they take current interpretations of ‘service’ for granted. But in normalizing specific definitions of service, methods of evaluating efficiency carry normative assumptions about ‘need’ forward, invisibly bedding them into future programmes of research and development.
> In conclusion, the un-reflexive pursuit of energy efficiency is problematic not because it does not work, or because the benefits are absorbed elsewhere, as the rebound argument suggests, but because it does work– via the necessary concept of equivalence of service – to sustain, perhaps escalate but never undermine [...] increasingly energy-intensive ways of life.
> In response, it is tempting to call for greater interdisciplinarity, and new ideas are definitely needed. However, as Daniels and Rose perceptively observed, it is no accident that the field of energy efficiency is ‘devoid of any vision of history’ (Daniels & Rose, 1982) This is not something that can be fixed since it is an unavoidable consequence of how programmes of efficiency are conceptualized. In the end, it is impossible to imagine how organizations like the IEA, the EU or the UK Committee on Climate Change might come to recognize and explicitly evaluate their own role in making and shaping present and future ‘needs’. At the same time, and as historians might well point out, the ambition of reproducing ‘present’ standards of living, now and in the years ahead, is doomed to fail.
Better energy efficiency is important, but only one path. And on it's own, it will be as effective as insisting on building smaller vacuum tubes.
>Even though better energy efficiency is great, the video highlights how policy for efficient housing requires minimising draft, which implies convection heating.
What on earth makes you think that? It's incorrect.
That literal sentence? But if you watched the first video, at the 3:25 mark it is mentioned that there is barely any air exchange with the environment (I'm gasping for air at the thought of it), and at 5:45 you see a heater in front of a window, which implies using air as the medium of heat transport[0][1]. Hence, convection heating.
Look, I don't know the Passive Housing standard, I'm inferring based on the information given in the video and article. If I'm wrong, don't just say "this is incorrect", tell me what the standard actually is.
Here in Japan it seems like for a long time it's been a competition to build the LEAST efficient houses possible, but recently it seems like all the ads for home builders are touting "ZEH" - Zero Energy House. Hopefully people actually choose to build these things too.
Coincidentally, from a couple days ago, here's an English language interview with the owner of a passive house in Karuizawa. There are also some general Japan-passive-house-related links in the article.
Lausanne was like that, not exactly the apps but on the southern nearby end. I venture that most of Europe has mild enough winters and summers outside of the extremes northern and southern parts.
On the other hand, in nearby Seattle which has similar climate, lots of hydro makes even electric heating fairly affordable. Also it’s in the middle of winter and my window is open, I don’t see a great need for it (maybe in the summer when it heats up and we don’t have AC).
I skipped on renting in a passive building in Bellevue I saw this summer because I couldn’t open the windows (well, there was one slip I could open just a little bit). It was a nice apartment at a decent discount as well.
The 10 Watt per square meter standard remains as part of the passive house definition, no matter what the climate. The article mentions this with respect to the large amounts of insulation required in really cold places. So there is no special requirement for fossil fuels.
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