9 ms·

"safe" in this context is virus safe. Can have a pretty good application for places where virus transmission is an issue, as long as people like me don't feel a

by a1371 5y ago

"safe" in this context is virus safe. Can have a pretty good application for places where virus transmission is an issue, as long as people like me don't feel an unease about being bombarded with UV 10 hours a day. When I think of "Safe" for air, I also think of PM2.5 and other airborne compounds. A more permanent fix to make the air fully safe is improving building ventilation.

mjevans 5y ago
IMO, as an armchair opinion, the LEED certification craze is much of the issue. * https://en.wikipedia.org/wiki/LEED https://en.wikipedia.org/wiki/LEED There's an almost blind focus on one dimension of a multi-dimensional problem. Yes, buildings should be designed to be more energy and environmentally efficient; where it makes sense. However there are many assumptions in 'building code' that evolved around implicit properties in the materials and methods used in the past. A more comprehensive evaluation would consider numerous factors and choose trade-offs. What is the (exterior) difference in impact between using different quantities and combinations of building materials? How do those materials need to be maintained or replaced over the life of the building? Over it's demolition? Can they be recycled or otherwise recovered? How do the used materials and shapes effect the operational energy for the intended use of the building (over the intended, and likely, lifetimes)? It looks like a 2014 update to LEED finally 'considers indoor environmental quality'. "... the IEQ category addresses thermal, visual, and acoustic comfort as well as indoor air quality." However my opinion is that they've put the cart before the horse. Surely you've seen office environments where someone doesn't like 'how cold' the building is; so they use a personal heater to blow directly on themselves. Or utilize an air filtration system for one room because it's impossible to clean the ventilation ducts. It also fails to consider containment of emissions from chemical / cleaning or other smelly areas. The acoustic angle is also critically important for apartments and condos. One of _the_ major reasons I and many others have grown to hate living in them revolves around __noise__. There are many memes about marching bands and various other sadistic neighbors on any adjacent side, particularly upstairs. If you want people to _want_ to move to apartments and condos, then they need to be built so they're desirable. That includes 'cave of solitude' level of audio isolation. Fresh air that doesn't have the cooking or laundry smells; or worse the trash chute leaking out because someone didn't setup the pressure system correctly. It also includes no more free-for-all parking and enough spaces for the cars people will bring with them from the suburbs. (Which might be as many as 2 per adult on average!) The car angle might be solved at the same time as municipal parking, if a big enough, and well secured enough, lot exists as an IO/interface with the surrounding areas. That level of thinking combined with people-mover sidewalks along pedestrian arterials will help us move towards 'Cave of Steel' like cities.
- Wowfunhappy 5y ago
  I don't think I agree. I think the need to reduce energy use to prevent climate change is so overwhelming, that no trade off is worth it. Yes, people's health are on the line, and it's difficult to argue against that—but unchecked climate change is also going to affect the health of an awful lot of people in the future, in worse ways. Obviously, if we can greatly improve indoor air quality with only a marginal increase in energy use, that's worth it. But anything else... I don't know! I think it's easy to forget just how big of a deal climate change is!
  - nitrogen 5y ago
    It's also easy to forget how big of a deal human health is. If you can spend 5% more energy to unlock 5% more enjoyment and productivity, you can use that extra productivity to engineer better, less polluting systems. If every high density apartment building had a much much higher air and sound quality than the average house, it would also entice more people to live in denser areas. Moreover, well-built, well-conditioned, comfortable buildings are also very efficient, so the only reason not to build for quality is up-front capital cost, a problem that can be solved with a combination of improved technology and tighter building standards for ventilation and noise. There should be a way to shop for places to live with an easily comparable air, sound, and comfort quality score, so that there is pressure to improve.
    - prox 5y ago
      Even during the pandemic their were active protests from companies against higher standards of ventilation where I live, even though the ventilation is already inadequate. Good ventilation would prevent lock downs. An article on this in the NYT by an expert rated that most ventilation is only 3-4 on a scale of ten. 7-8 would prevent a lot of transmission.
- nitrogen 5y ago
  If you want people to _want_ to move to apartments and condos, then they need to be built so they're desirable. Yes, absolutely this. Ever since I was a kid playing Sim City and seeing the Arcologies I dreamed of living in a high rise apartment. Eventually in my 30s I was able to do so, and the whole experience was terrible. Sure, the place looked great in photos. But the lint and smells from laundry, cooking, weed, bathrooms, etc. all got funneled into my unit, and the soundproofing was nowhere near adequate. These buildings, if they have operable windows, really need isolated per-unit ventilation systems (with a hydronic loop for heat/cold) and, as you say, dead silent soundproofing. So now I'm back into a house with no shared walls. It's also poorly built, but it's way quieter way out here than in a city, and overall much higher quality of life. And I can still drive or take a train downtown to access food/etc.
angry_octet 5y ago
I don't think you're getting UV10 so much, but there is real risk in the production of other chemicals, which this study is really ignoring. Improving exterior airflow and particle filtration is a much safer option.
- forum_ghost 5y ago
  UV strong enough to kill off pathogens will likely produce some ozone.
- sandworm101 5y ago
  I have to wonder how various materials will react. A simple plastic layer on a counter could yellow and degrade very quickly. And im sure that all sorts of drugs will need to be stored in dark boxes else they too degrade into who knows what.
novok 5y ago
You could add it as another 'filter' for a general HVAC filtration & ventilation system. Nobody would actually need to be exposed to the UVC light, and you could do potentially do other wavelengths that would not be the safest to expose people to but would be more effective. It would also be good for a retrofit filter, because adding a light to an HVAC conduit means you don't need to increase the power of a current HVAC fan to push through filter material, and you'd probably wont need to replace the 'filter' that often either.
- bonestamp2 5y ago
  Additionally, in room units could activate only when there is nobody in a room... like reverse occupancy lights. Slight movement would switch them off. If it was really harmful, a notification could indicate they are about to come if there is no movement. This would not be appropriate for every type of room of course, but more filtration the better where it is practical.
  - detritus 5y ago
    Aside from humans, would this radiation not also screw with dyes, paints and possibly plastic coherence in a room?
    - bonestamp2 5y ago
      Sure, I assume anything that is not UV safe could be a problem. In institutional environments, this could be planned for. A lot of plastics are coated with UV treatments already.
- rocqua 5y ago
  I believe an upside of the 'in-room' UV approach is that it also cleans exposed surfaces. Putting the UV light only in the air-ducting does little to clean a surface someone coughed on. Whereas the UV approach would help to disinfect those surfaces.
mattlondon 5y ago
It could be useful in non-office situations too. E.g. on the London underground where you are stuck in a tim-can for 5-20 mins etc without any fresh air circulation
Spooky23 5y ago
The obvious solution that yields 90% of the benefit at 5% of the cost is to open the window and increase ventilation. (Although admittedly not addressing particulate issues if that’s a problem) Since most building standards are set by the society of HVAC engineers, there’s a pretty obvious bias, and efficiency people seem to take the bait. We tend to use these systems to make shittier buildings marginally ok for human habitation. Architects care about $/ft for normal buildings and cool looking designs that get them awards for fancy buildings.

by a1371 5y ago

mjevans 5y ago

IMO, as an armchair opinion, the LEED certification craze is much of the issue. * https://en.wikipedia.org/wiki/LEED https://en.wikipedia.org/wiki/LEED There's an almost blind focus on one dimension of a multi-dimensional problem. Yes, buildings should be designed to be more energy and environmentally efficient; where it makes sense. However there are many assumptions in 'building code' that evolved around implicit properties in the materials and methods used in the past. A more comprehensive evaluation would consider numerous factors and choose trade-offs. What is the (exterior) difference in impact between using different quantities and combinations of building materials? How do those materials need to be maintained or replaced over the life of the building? Over it's demolition? Can they be recycled or otherwise recovered? How do the used materials and shapes effect the operational energy for the intended use of the building (over the intended, and likely, lifetimes)? It looks like a 2014 update to LEED finally 'considers indoor environmental quality'. "... the IEQ category addresses thermal, visual, and acoustic comfort as well as indoor air quality." However my opinion is that they've put the cart before the horse. Surely you've seen office environments where someone doesn't like 'how cold' the building is; so they use a personal heater to blow directly on themselves. Or utilize an air filtration system for one room because it's impossible to clean the ventilation ducts. It also fails to consider containment of emissions from chemical / cleaning or other smelly areas. The acoustic angle is also critically important for apartments and condos. One of _the_ major reasons I and many others have grown to hate living in them revolves around __noise__. There are many memes about marching bands and various other sadistic neighbors on any adjacent side, particularly upstairs. If you want people to _want_ to move to apartments and condos, then they need to be built so they're desirable. That includes 'cave of solitude' level of audio isolation. Fresh air that doesn't have the cooking or laundry smells; or worse the trash chute leaking out because someone didn't setup the pressure system correctly. It also includes no more free-for-all parking and enough spaces for the cars people will bring with them from the suburbs. (Which might be as many as 2 per adult on average!) The car angle might be solved at the same time as municipal parking, if a big enough, and well secured enough, lot exists as an IO/interface with the surrounding areas. That level of thinking combined with people-mover sidewalks along pedestrian arterials will help us move towards 'Cave of Steel' like cities.

Wowfunhappy 5y ago
I don't think I agree. I think the need to reduce energy use to prevent climate change is so overwhelming, that no trade off is worth it. Yes, people's health are on the line, and it's difficult to argue against that—but unchecked climate change is also going to affect the health of an awful lot of people in the future, in worse ways. Obviously, if we can greatly improve indoor air quality with only a marginal increase in energy use, that's worth it. But anything else... I don't know! I think it's easy to forget just how big of a deal climate change is!
- nitrogen 5y ago
  It's also easy to forget how big of a deal human health is. If you can spend 5% more energy to unlock 5% more enjoyment and productivity, you can use that extra productivity to engineer better, less polluting systems. If every high density apartment building had a much much higher air and sound quality than the average house, it would also entice more people to live in denser areas. Moreover, well-built, well-conditioned, comfortable buildings are also very efficient, so the only reason not to build for quality is up-front capital cost, a problem that can be solved with a combination of improved technology and tighter building standards for ventilation and noise. There should be a way to shop for places to live with an easily comparable air, sound, and comfort quality score, so that there is pressure to improve.
  - prox 5y ago
    Even during the pandemic their were active protests from companies against higher standards of ventilation where I live, even though the ventilation is already inadequate. Good ventilation would prevent lock downs. An article on this in the NYT by an expert rated that most ventilation is only 3-4 on a scale of ten. 7-8 would prevent a lot of transmission.
nitrogen 5y ago
If you want people to _want_ to move to apartments and condos, then they need to be built so they're desirable. Yes, absolutely this. Ever since I was a kid playing Sim City and seeing the Arcologies I dreamed of living in a high rise apartment. Eventually in my 30s I was able to do so, and the whole experience was terrible. Sure, the place looked great in photos. But the lint and smells from laundry, cooking, weed, bathrooms, etc. all got funneled into my unit, and the soundproofing was nowhere near adequate. These buildings, if they have operable windows, really need isolated per-unit ventilation systems (with a hydronic loop for heat/cold) and, as you say, dead silent soundproofing. So now I'm back into a house with no shared walls. It's also poorly built, but it's way quieter way out here than in a city, and overall much higher quality of life. And I can still drive or take a train downtown to access food/etc.

angry_octet 5y ago

I don't think you're getting UV10 so much, but there is real risk in the production of other chemicals, which this study is really ignoring. Improving exterior airflow and particle filtration is a much safer option.

forum_ghost 5y ago
UV strong enough to kill off pathogens will likely produce some ozone.
sandworm101 5y ago
I have to wonder how various materials will react. A simple plastic layer on a counter could yellow and degrade very quickly. And im sure that all sorts of drugs will need to be stored in dark boxes else they too degrade into who knows what.

novok 5y ago

You could add it as another 'filter' for a general HVAC filtration & ventilation system. Nobody would actually need to be exposed to the UVC light, and you could do potentially do other wavelengths that would not be the safest to expose people to but would be more effective. It would also be good for a retrofit filter, because adding a light to an HVAC conduit means you don't need to increase the power of a current HVAC fan to push through filter material, and you'd probably wont need to replace the 'filter' that often either.

bonestamp2 5y ago
Additionally, in room units could activate only when there is nobody in a room... like reverse occupancy lights. Slight movement would switch them off. If it was really harmful, a notification could indicate they are about to come if there is no movement. This would not be appropriate for every type of room of course, but more filtration the better where it is practical.
- detritus 5y ago
  Aside from humans, would this radiation not also screw with dyes, paints and possibly plastic coherence in a room?
  - bonestamp2 5y ago
    Sure, I assume anything that is not UV safe could be a problem. In institutional environments, this could be planned for. A lot of plastics are coated with UV treatments already.
rocqua 5y ago
I believe an upside of the 'in-room' UV approach is that it also cleans exposed surfaces. Putting the UV light only in the air-ducting does little to clean a surface someone coughed on. Whereas the UV approach would help to disinfect those surfaces.

mattlondon 5y ago

It could be useful in non-office situations too. E.g. on the London underground where you are stuck in a tim-can for 5-20 mins etc without any fresh air circulation

Spooky23 5y ago

The obvious solution that yields 90% of the benefit at 5% of the cost is to open the window and increase ventilation. (Although admittedly not addressing particulate issues if that’s a problem) Since most building standards are set by the society of HVAC engineers, there’s a pretty obvious bias, and efficiency people seem to take the bait. We tend to use these systems to make shittier buildings marginally ok for human habitation. Architects care about $/ft for normal buildings and cool looking designs that get them awards for fancy buildings.