11 ms·

I've been thinking about the inverse problem. I live in a very warm city. Air conditioning (cooling spaces) is the norm, but tons of money are spent with instal

• johntash 5y ago
  Just curious, what part of the world do you live in? I've lived in cities where we experience anything between below zero to 120F throughout the year. I couldn't imagine not having AC/Heating in those areas even with more efficient ventilation/insulation.
  • myth2018 5y ago
    How, that's a huge temperature gradient. I live in Fortaleza, Brazil. Temperatures here are very stable along the whole year (78F - 90F, it rarely falls out of this interval). I'm not advocating this no-AC model as a general solution though. I'm aware we're a bit lucky here. I used to live in Sao Paulo and temperatures vary more wildly there, sometimes within a single day.
    • pc86 5y ago
      Any temperate area on the planet will easily have 90-100 degree swings throughout the year. I used to live on the US East Coast and a summer high of 90-95 and winter lows of 0-5 were common my entire childhood. I moved to the midwest in the early summer and it hit 100 more than once, and it's been below 0 multiple times this winter already.
      • myth2018 5y ago
        We are near to the equator here. Seasons don't work the same. Here they call the 3 rainy months "winter", and the rest of the year is summer. And the temperature gradient I've mentioned is correct. No noticeable changes along the whole year, I'm sorry.
        • rootusrootus 5y ago
          > No noticeable changes along the whole year, I'm sorry. It does sound kind of unpleasant, but I imagine you get used to it.
          • joshgachnang 5y ago
            I grew up in the Midwest and lived in SF and LA for a few years each. I definitely missed the seasons changing and appreciated them even more moving back to the Midwest. Lack of seasons really messed with my sense of time, like: "Oh that thing we did last month...oh woah that was six months ago??"
            • hedora 5y ago
              You can come back to the SF area. Thanks to climate change, we have four seasons now: Not enough rain / sunny and 50 F Sunny and 70F; green plants Sunny and 90-105 F; brown plants Red Skies, ??? F; black plants / red embers
          • myth2018 5y ago
            Yes, we get used to it, not unpleasant for me, at all. But it changes the way you live. Compared with lives of friends from Europe, I notice that theirs has a bit more of a "structure" and predictability. E.g., hang out more in the summer, doing more reading and writing more in the winter. I think I would enjoy that. Of course I could plan my life based in months instead of seasons, but it's not the same, especially considering that people around me wouldn't be following that same plan.
            • 5y ago
  • brewtide 5y ago
    Mainer checking in. Wednesday afternoon it was 70F. The next morning it was 5F Friday a snowstorm. Today -2F in AM. We all just dress in endless layers.
    • pc86 5y ago
      Worth it for the lobster rolls though, right?
• bigthymer 5y ago
  In traditional Iranian design, they would paint a chimney black to generate a constant updraft. It works in dry areas.
• maxerickson 5y ago
  Ventilation doesn't help much with humidity, which frequently overlaps with the heat. I get by without AC in the northern Midwest, but I'd be inclined to get a window unit if there was more than a few uncomfortable nights a year.
  • myth2018 5y ago
    Uhm.. for me it helps, and A LOT. Surely there are more factors involved, which I'm not aware of. I'm talking from Fortaleza, Brazil. Maybe the sea is bringing cooler air. I really don't know, I only have these pieces of empirical knowledge and my experience is very narrow, basically limited to this city.
    • TylerE 5y ago
      A large body of water near by certainly has a moderating effect on temperature. I looked up the climate data for Fortaleza, and compared it to my town (random US city, about 35 degrees northern latitude, so not super far south or anything.) Our average daily highs in summer are only about 1 degree (C) lower than your RECORD highs... your averages are about 9C lower than ours. Without AC here it would be...supremely unpleasant, and well other the threshold of danger for anyone with any sort of medical issues.
      • myth2018 5y ago
        Our air masses are probably cooler than yours because of the sea, I'm not sure. There seems to be more factors in operation.
      • dahfizz 5y ago
        This is something that I don't think Europeans appreciate. Most of the USA is way hotter and way colder than most of Europe
    • deleted 5y ago
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  • twelvechairs 5y ago
• brtkdotse 5y ago
  Ventilation and air conditioning are two very different things. Unless it’s a central unit, the AC will be reusing the same air. In order to not die of lack of oxygen you need ventilation as well.
  • myth2018 5y ago
    Interestingly, the articles I find about ventilation are indeed concerned about air quality. However, in my country, at least in the cities I've lived on, the idea of ventilation is mostly associated to cooling indoors (with air quality being a desirable byproduct). Maybe the differences between our climates led to differences between the concepts behind the same word. Or maybe there's a better word in English to express what I'm intending to (sorry, English is not my mother language).
  • pchwalek 5y ago
    I think you can only separate them in radiative systems. But otherwise, a modern commercial HVAC system has a degree of mixing the air from the outside world to reduce gas and particulate concentrations. So in some systems, the HVAC is the ventilation system but when only ventilating, the flow rate is stepped down and the conditioning system is inactive.
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• nicoburns 5y ago
  IMO the real solution is building materials with high heat mass (e.g. stone), and architectural designs which allow for passive cooling. This exists already, but can be expensive to build.
  • kevin_thibedeau 5y ago
    An alternative is heating panels that emit long IR. These allow you to maintain a lower air temperature and still be comfortable when they're shining on you.
    • spaetzleesser 5y ago
      How even is that warming you get from them? I find it very uncomfortable to sit outside at a restaurant where they have heaters. One side gets roasted and the other is cold.
      • kevin_thibedeau 5y ago
        The same way the sun warms you when you walk out of the shade. Air temperature is the same but you feel warmer. Long IR is completely different than conventional heating elements that can only heat air.
      • samatman 5y ago
        There's such variety in comfort. Being too warm on one side and too cold on another is one of my favorite ways to be.
        • dotancohen 5y ago
          I too love campfires.
  • tapland 5y ago
    Lived in a stone house when I was younger. It was amazing at keeping us cool or warm for long periods when the temperature shifted. In current apartment heating doesn't work properly until days after its gotten cold, and it's instantly too warm when it gets warm. AC is very uncommon in Scandinavia, and we have 85-95% humidity in my area year around.
• throw0101a 5y ago
  > The new houses are designed with zero consideration about ventilation, designers seem to take for granted that you are going to buy an AC system. These are two separate problems. In the ideal situation, you generally want the house to be fairly air tight and condition the air for (a) temperature and (b) humidity. Each of (a) and (b) are taken care of by different mechanical units: one is monitored by a thermometer and the other by an hygrometer. The latter triggers a stand alone dehumidifier: * https://www.aprilaire.com/whole-house-products/dehumidifiers https://www.aprilaire.com/whole-house-products/dehumidifiers For fresh air you have an HRV/ERV, which brings outside air (through a filter) into the house (usually to bedrooms), while at the same time blowing out stale inside air (usually taken from bathrooms and the kitchen), with the two moving through the unit so that the outgoing air tempers the incoming air: * https://www.ecohome.net/guides/2276/choosing-between-an-hrv-and-an-erv/ https://www.ecohome.net/guides/2276/choosing-between-an-hrv-... You still have opening windows, as they're mandated for emergency fire exits.
  • kccqzy 5y ago
    This is exactly the problem with newer design and construction philosophy. Its premise is that we will use mechanical systems, and then try to make these mechanical systems more efficient such as improving insulation, using multi-stage condensers for the AC, etc. This is epitomized in the passive house concept. In contrast the older philosophy is that natural ventilation is good enough, so we design houses to improve that, such as strategic placement of windows to allow cross ventilation, use high ceilings to allow heat to rise, etc. The original article is squarely in the second camp.
    • myth2018 5y ago
      Indeed. Speaking about hot and sunny cities like mine, besides strategic placement of windows I would also mention barriers to direct sunlight over the walls. Simple barriers can improve inner temperatures sensibily and costs no energy, but most projects don't take that in consideration. Jesus, here there are even buildings importing those "glass wall" concepts, which makes total sense in climates like European's and north American's, but makes absolutely no sense in sunny cities -- you just end up aggravating the greenhouse effect and having to rely more heavily on AC. Everything because of façade aesthetics.
• pchwalek 5y ago
  I would disagree with new houses not considering ventilation. There are set building standards (ASHRAE 62.1, 62.2, and ISO standards) that have been around for a while that specify how ventilated spaces should be for given use cases. There’s a more recent trend to evolve these standards to take into consideration non-hazardous levels of particulate matter and gases that still show cognitive impairment—-I’m currently exploring this topic area for my PhD work. What we’re seeing, though, are tighter building envelopes so that the structure is thermally efficient. However, with a tighter envelope, active/natural ventilation systems becomes even more important than in older structures where there is some rate of natural air exchange with the exterior through building cracks and terrible (by todays standards) windows. There are companies coming up that are looking at “Personal Comfort Systems” and there is a fair amount of active research in this area (ex., https://cbe.berkeley.edu/research/personal-comfort-system/ https://cbe.berkeley.edu/research/personal-comfort-system/). It’s an interesting space since you have essentially two knobs to play with: (1) a persons actual heat exchange with the environment and (2) a persons perceived heat exchange.
  • coryrc 5y ago
    That's for keeping air safe for humans, not using passive ventilation as a replacement for HVAC equipment.
  • hedora 5y ago
    Modern building codes do carefully consider ventilation, but I think a lot of knowledge and tradecraft have been lost. If you're lucky and live in an older house of the correct design from just before A/C, (most of the oldest two-story single family homes in Berkeley, FWIW) you might notice that some of the internal walls stay well below room temperature during the summer. The buildings typically have pier and beam foundations, and the cooling walls have passive draft ways that pull cool air over the ground under the house and up against those walls. This is great in the summer, but not so much in the winter. I don't know how they use convection to pull cold air up, or how they prevent moldy foundation dirt air from permeating the house. I've heard there are some pretty clever designs, but (of course) they're hidden behind walls. Anyway, our modern house is one story, and has an intentionally-uninsulated concrete slab on grade foundation, so we get a similar effect. (Passive solar heat keeps it toasty in the winter.) We usually have our windows open, but we also over-insulated the walls (for noise and efficiency), and have a tight building envelope, so the heating/cooling bill is tiny. (Edit: I bet they vented the walls into the attic and under the floor. That'd create a strong updraft in the summer (out the attic vents), but (if the attic is well insulated against the rest of the house) not in the winter.
• GeekyBear 5y ago
  I had family members who lived in a home in the deep south that was built before air conditioning was common. It had a large fan in the ceiling of a central hallway that vented the air from the inside the house out through the attic. This was an industrial grade fan that moved a huge volume of air. At bedtime, they could open the bedroom windows and turn on the fan and a stiff wind would blow in through all the bedroom windows in the house. That fan, along with window awnings and tall ceilings, really made a difference in how often they needed to use air conditioning, even near the Gulf of Mexico.
  • inter_netuser 5y ago
    what state and what was the average humidity, or even better dew point? I personally find fans made very little difference for me in humid climates.
    • erosenbe0 5y ago
      Fans don't improve comfort as much if humidity is high, because the airflow doesn't cause as much evaporative cooling on the skin. So you need a temperature gradient to get a good effect. Attic fans are a good example. The attic tends to get hotter than the outside air when the sun is shining, and the fan helps equalize.
    • Izkata 5y ago
      GP and GGP are describing different methods of cooling: Sitting in a breeze does two things: 1) Allows your sweat to evaporate more quickly, and that evaporation is what causes most of the cooling effect. It's not very effective in high humidity because your sweat won't evaporate very easily. Evaporative coolers / swamp coolers work off this same principle. 2) Sitting in the still indoor air your body heat warms the air around yourself and you end up sitting in that pocket of heat. Just about any airflow stops that, which is why air circulators (fans that are meant to point from one end of a room to another instead of directly on a person) work to make a room feel a bit cooler. Running the attic fan at night with open windows can have similar effects as above (especially the air circulator), but on top of that it's for pulling in the air from outdoors after it's cooled off at night, and expelling the warmed-up air that accumulates near the ceilings and roof. You'd want to close windows in the morning so the warmed-up air doesn't get pulled in and replace all the cooler air.
• animal_spirits 5y ago
  There is an article on the notechmagazine site about ancient air conditioning here: https://www.notechmagazine.com/category/air-conditioning https://www.notechmagazine.com/category/air-conditioning Really interesting architectural technologies came out back in the day.
• naravara 5y ago
  Ventilation is so underrated. There is not only the obvious benefit in reducing electricity usage, but it helps with noise (AC doesn’t run as often), dust (free flowing air keeps it from collecting in air-flow deadzones), mildew (as with dust, air flow keeps moisture and humidity from concentrating in one spot), and the longevity of your appliances (cumulative effect of all of the above).
• egypturnash 5y ago
  I live in an old shotgun double in New Orleans. A lot of the features designed for airflow have been fucked up by “modernization” - most of the windows are permanantly closed due to window AC units, transom windows above the doors between rooms are painted shut with the hinge support stuff gone, etc - but it’s still really amazing how much colder it is than the outside. It is designed to shed heat in a ton of ways and it’s so much better at it than the newer house in the same city I grew up in.
• culi 5y ago
  In Europe still today AC usage is at less than 5% of all households. Sure the US likely has more cities in really hot places, but ACs are still generally an American thing
  • hedora 5y ago
    They say air conditioning settled the west. Desertification in that area is starting to roll that back though. Never-irrigated ranches are drying up. Without argiculture, the towns die. The ecosystems don't recover, even in places where the people are gone and the buildings have rotted to dust and blown away (too hot / no rain). This must have been how people felt when the Sahara turned into a desert. I can't believe it's happening so fast. (Towns that were populated 20 years ago are completely invisible now.)
    • culi 5y ago
      Not to mention the onset of a new Dust Bowl[0] [0] https://www.youtube.com/watch?v=THSm-I790H0 https://www.youtube.com/watch?v=THSm-I790H0 (PBS Eons vid about it)
• MrRobotics 5y ago
  The energy savings from spot cooling with fans can be incredible compared to AC. A garage AC unit consumes ~1300W while a 20” fan consumes about ~150W. My startup, Following Fan, has built a person-tracking 20” fan that uses computer vision to automatically stay pointed at the user as they move around. This technology provides the location agnostic benefits of AC with the energy consumption of fans.
  • jiggunjer 5y ago
    But ac also reduce humidity. Fans just blow air, at high humidity and high temps the fan would be useless?
    • silisili 5y ago
      Yeah, this is a big one for people in humid climates. Here, it doesn't get that cold in the winter, but the house gets absolutely balmy and gross feeling. I have to turn the AC on just to get some humidity out of the air, despite it being in the 60s or 70s. I have a dehumidifier also, but it can't do the job alone. It's really weird seeing how much water it sucks out of the air.
    • MrRobotics 5y ago
      You’re right that fans don’t affect humidity and are less effective in extreme heat. However, there are many places such as garages, airplane hangers, and large warehouses where AC is impractical due to a lack of insulation and the need to open large doors to move vehicles or goods in and out. In those environments, fans are about the best cooling solution you can get. One big issue with traditional fans though is that they just point in an single direction or oscillate back and forth regardless of the location of the user.