5 ms·

> There are so many rooms, classrooms, movie theaters and other places with poor ventilation where you just feel dizzy, or fall asleep, not knowing it was just

> There are so many rooms, classrooms, movie theaters and other places with poor ventilation where you just feel dizzy, or fall asleep, not knowing it was just due to lower oxygen levels in your blood. Raising awareness is the only real solution. Not wrong, but it is perhaps worth noting that there are already standards for proper ventilation. Generally you're looking at 5–10 cfm/person (2.5-5 L/s), depending on the facility and purpose of the room; see Table 6.2.2.1 in ASHRAE Standard 62.1 for the US: * https://www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards%20addenda/62_1_2013_p_20150707.pdf https://www.ashrae.org/file%20library/technical%20resources/... Maybe set up a monitor, but if the room/facility has recently been renovated and meets modern (>2013) building codes, this 'should' have already been taken into account.

wouldbecouldbe 3mo ago
I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation
- avhception 3mo ago
  A friend of mine recently moved to a modern apartment, built only a few years ago to a very high isolation standard (Germany). I stayed over night and slept on his couch, the air got really really dry and stuffy. It was really uncomfortable.
- hydevito 3mo ago
  Stayed at a beautiful new house in Finland, with five people instead of the usual two, the CO2 detector intermittently went off while we were sleeping. Which the hosts assured us was a faulty detector. They also spoke to how extremely energy efficient the house was, to us it seemed like there wasn't enough ventilation, to improve the insulation. Against their wishes, I slept with all windows fully cracked, which was only ~2 inches due to the "efficient" design.
  - pieterhg 3mo ago
    This was probably CO not CO2? A CO2 monitor doesn't "go off", it just silently reports. CO would go off because it's deadly to have a CO leak.
    - 317070 3mo ago
      My portable CO2 monitor goes off. You can set a levels of warning on the aranet. It is a very quiet, non-disruptive alarm, but an alarm nonetheless. I agree with OP. I don't always carry it along, but it has been a massive boost to my productivity.
  - jltsiren 3mo ago
    Poor ventilation is mostly an issue in homes built or renovated in the 1970s, when the oil crisis led to ill-considered efforts to save energy. New homes typically achieve energy efficiency by using heat pumps in the ventilation system.
- OptionOfT 3mo ago
  How modern? We built or house in Belgium in 2016, and it was completely sealed, very well insulated, but the air quality was good because we had mechanical ventilation. Clean air blown in, stale air extracted which then went through a heat exchanger. The only issue this house had was it overheated. We had glass facing south. Even in winter it instantly became too hot.
- HPsquared 3mo ago
  Heat recovery ventilation is the answer to this. You also get the benefit of being able to filter it.
  - throw0101a 3mo ago
    Energy recovery ventilation is the answer to this. HRVs only deal with temperature, but then you have humidity that is non-controlled: moisture coming in during the summer, and getting vented out in the winter (too-dry air coming in). ERVs handle both.
- throw0101a 3mo ago
  > I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation The link I pointed to is all about ventilation, so just because people ignored an important component of building science, and focused on one aspect, does not invalidate it. And while climate change is important and using efficiency to deal with it is useful, the thermal control layer is actually the least important of the four: * https://buildingscience.com/documents/insights/bsi-001-the-perfect-wall https://buildingscience.com/documents/insights/bsi-001-the-p... 'Bulk' water (precipitation) and moisture can cause deterioration of the building materials (rot, crumbling), and also mold, which has its own health effects. Leaky houses can often blow conditioned air at much faster rates than thermal leakage.
II2II 3mo ago
Building codes that address this are wonderful, however: - Plenty of people live or work in older buildings, where are not up to standard. For example: my office probably violates the air quality sensibilities of the Victorian era, which is when it was originally built. - Equipment breaks down, isn't operated properly, or wasn't installed correctly. Having monitors that measure air quality is an extra check. While you may not be able to get direct action upon a consumer sensor, it can help you push for action. I've been in buildings of varying quality over the years. I've seen how it takes time to get people in to do air quality testing. Heck, I saw the government claim that the air quality was acceptable in schools during the pandemic because the schools had passive ventilation systems. That meant they could open windows. (To be fair, the air quality in most of those buildings was probably fine since that was how the buildings were designed. That said, such standards make it easy for some buildings to slip through the cracks.) So yeah, sensors to the people!
- bloomingeek 3mo ago
  And let's not forget unscrupulous building owners/renters who will not employ the at least 10% fresh air intake rule on their HVAC system. This fresh air is outside air temperature, so their system has to change it's temp according to the thermostat setting, which costs money.
  - account42 3mo ago
    Fresh air doesn't have to be outside temperatures as you can heat exchange most of the energy from exhaust to intake without putting in additional power.
    - bloomingeek 3mo ago
      True, but the vast amount of buildings don't have this technology.
xyzzy_plugh 3mo ago
This is correct, but there's still a lot of opportunity to do better. I've been involved with the build out of several office spaces in new and old buildings. We always took this sort of thing seriously and measured each room independently for a week (many at a time) ensuring we accounted for periods of high occupancy. This let us tune the HVAC systems to operate more efficiently, ensuring comfortable temperatures and air circulation. Every time I've seen this done there were structural deficiencies that required remediation, some times it meant adjusting duct work. Most modern office buildings are designed to be a platform for constructing spaces, as spaces usually evolve and change between leases and tenants. They're designed to accommodate this sort of thing. However I've found that no build out nails this the first time. It's very hard! Often times things look fine but once you get people in the space things change drastically. It requires time and effort to address. Several of my offices had such good air that I'd prefer being there over pretty much anywhere else -- even outside on poor AQI days. I've also found that a lot of offices don't do any of this and their air quality is noticeably poor. And lastly I've found that the oldest buildings, including schools -- and I'm talking really old -- have very good air because they are so incredibly leaky. They're usually harder to cool and heat, though.
josephg 3mo ago
Should… Whenever I travel, I bring a CO2 meter with me. It’s amazing how often the air is bad. Often in unexpected places. My meter hit 3100 in an uber once. I didn’t even notice until I got to my hotel room and looked at the data log. It was a fresh, hot day outside. The uber had windows closed and AC on. I bet he had no idea - but he was driving with significant cognitive impairment. Takeoff and landing in planes are always the worst. If you get sleepy as the plane is taking off, it’s not you. The plane’s ventilation doesn’t work properly when the plane is stationary. So before a plane is in the air, they often hit 2500.
- quickthrowman 3mo ago
  When was the last time you had that sensor calibrated properly with a can of test gas and a multimeter?
  - colechristensen 3mo ago
    Take it outside, as long as it measures 400-450 it's probably good. Metrology calibration is necessary if you want accuracy better than 10%, but most of us don't care at all about that, instead we care about increments of 200ppm or more.
    - ShinyLeftPad 3mo ago
      Local factors can make your CO2 fluctuate by 200ppm. If you're near a busy road with not a lot of wind 600 ppm is possible. But it's not that important if you open your window at 1000 ppm or 1200 ppm.
    - jameshart 3mo ago
      Haha yes. 400-450ppm is fine. We’re doing just fine here. Everything is okay. https://www.co2levels.org/ https://www.co2levels.org/
      - jaapz 3mo ago
        The comment was about the accuracy of the sensor, not about raising CO2 levels across the globe.

wouldbecouldbe 3mo ago

I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation

avhception 3mo ago
A friend of mine recently moved to a modern apartment, built only a few years ago to a very high isolation standard (Germany). I stayed over night and slept on his couch, the air got really really dry and stuffy. It was really uncomfortable.
hydevito 3mo ago
Stayed at a beautiful new house in Finland, with five people instead of the usual two, the CO2 detector intermittently went off while we were sleeping. Which the hosts assured us was a faulty detector. They also spoke to how extremely energy efficient the house was, to us it seemed like there wasn't enough ventilation, to improve the insulation. Against their wishes, I slept with all windows fully cracked, which was only ~2 inches due to the "efficient" design.
- pieterhg 3mo ago
  This was probably CO not CO2? A CO2 monitor doesn't "go off", it just silently reports. CO would go off because it's deadly to have a CO leak.
  - 317070 3mo ago
    My portable CO2 monitor goes off. You can set a levels of warning on the aranet. It is a very quiet, non-disruptive alarm, but an alarm nonetheless. I agree with OP. I don't always carry it along, but it has been a massive boost to my productivity.
- jltsiren 3mo ago
  Poor ventilation is mostly an issue in homes built or renovated in the 1970s, when the oil crisis led to ill-considered efforts to save energy. New homes typically achieve energy efficiency by using heat pumps in the ventilation system.
OptionOfT 3mo ago
How modern? We built or house in Belgium in 2016, and it was completely sealed, very well insulated, but the air quality was good because we had mechanical ventilation. Clean air blown in, stale air extracted which then went through a heat exchanger. The only issue this house had was it overheated. We had glass facing south. Even in winter it instantly became too hot.
HPsquared 3mo ago
Heat recovery ventilation is the answer to this. You also get the benefit of being able to filter it.
- throw0101a 3mo ago
  Energy recovery ventilation is the answer to this. HRVs only deal with temperature, but then you have humidity that is non-controlled: moisture coming in during the summer, and getting vented out in the winter (too-dry air coming in). ERVs handle both.
throw0101a 3mo ago
> I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation The link I pointed to is all about ventilation, so just because people ignored an important component of building science, and focused on one aspect, does not invalidate it. And while climate change is important and using efficiency to deal with it is useful, the thermal control layer is actually the least important of the four: * https://buildingscience.com/documents/insights/bsi-001-the-perfect-wall https://buildingscience.com/documents/insights/bsi-001-the-p... 'Bulk' water (precipitation) and moisture can cause deterioration of the building materials (rot, crumbling), and also mold, which has its own health effects. Leaky houses can often blow conditioned air at much faster rates than thermal leakage.

II2II 3mo ago

Building codes that address this are wonderful, however: - Plenty of people live or work in older buildings, where are not up to standard. For example: my office probably violates the air quality sensibilities of the Victorian era, which is when it was originally built. - Equipment breaks down, isn't operated properly, or wasn't installed correctly. Having monitors that measure air quality is an extra check. While you may not be able to get direct action upon a consumer sensor, it can help you push for action. I've been in buildings of varying quality over the years. I've seen how it takes time to get people in to do air quality testing. Heck, I saw the government claim that the air quality was acceptable in schools during the pandemic because the schools had passive ventilation systems. That meant they could open windows. (To be fair, the air quality in most of those buildings was probably fine since that was how the buildings were designed. That said, such standards make it easy for some buildings to slip through the cracks.) So yeah, sensors to the people!

bloomingeek 3mo ago
And let's not forget unscrupulous building owners/renters who will not employ the at least 10% fresh air intake rule on their HVAC system. This fresh air is outside air temperature, so their system has to change it's temp according to the thermostat setting, which costs money.
- account42 3mo ago
  Fresh air doesn't have to be outside temperatures as you can heat exchange most of the energy from exhaust to intake without putting in additional power.
  - bloomingeek 3mo ago
    True, but the vast amount of buildings don't have this technology.

xyzzy_plugh 3mo ago

This is correct, but there's still a lot of opportunity to do better. I've been involved with the build out of several office spaces in new and old buildings. We always took this sort of thing seriously and measured each room independently for a week (many at a time) ensuring we accounted for periods of high occupancy. This let us tune the HVAC systems to operate more efficiently, ensuring comfortable temperatures and air circulation. Every time I've seen this done there were structural deficiencies that required remediation, some times it meant adjusting duct work. Most modern office buildings are designed to be a platform for constructing spaces, as spaces usually evolve and change between leases and tenants. They're designed to accommodate this sort of thing. However I've found that no build out nails this the first time. It's very hard! Often times things look fine but once you get people in the space things change drastically. It requires time and effort to address. Several of my offices had such good air that I'd prefer being there over pretty much anywhere else -- even outside on poor AQI days. I've also found that a lot of offices don't do any of this and their air quality is noticeably poor. And lastly I've found that the oldest buildings, including schools -- and I'm talking really old -- have very good air because they are so incredibly leaky. They're usually harder to cool and heat, though.

josephg 3mo ago

Should… Whenever I travel, I bring a CO2 meter with me. It’s amazing how often the air is bad. Often in unexpected places. My meter hit 3100 in an uber once. I didn’t even notice until I got to my hotel room and looked at the data log. It was a fresh, hot day outside. The uber had windows closed and AC on. I bet he had no idea - but he was driving with significant cognitive impairment. Takeoff and landing in planes are always the worst. If you get sleepy as the plane is taking off, it’s not you. The plane’s ventilation doesn’t work properly when the plane is stationary. So before a plane is in the air, they often hit 2500.

quickthrowman 3mo ago
When was the last time you had that sensor calibrated properly with a can of test gas and a multimeter?
- colechristensen 3mo ago
  Take it outside, as long as it measures 400-450 it's probably good. Metrology calibration is necessary if you want accuracy better than 10%, but most of us don't care at all about that, instead we care about increments of 200ppm or more.
  - ShinyLeftPad 3mo ago
    Local factors can make your CO2 fluctuate by 200ppm. If you're near a busy road with not a lot of wind 600 ppm is possible. But it's not that important if you open your window at 1000 ppm or 1200 ppm.
  - jameshart 3mo ago
    Haha yes. 400-450ppm is fine. We’re doing just fine here. Everything is okay. https://www.co2levels.org/ https://www.co2levels.org/
    - jaapz 3mo ago
      The comment was about the accuracy of the sensor, not about raising CO2 levels across the globe.