I am surprised that so few people discuss the centralized, presumably less-wasteful, less-cluttered alternative that is a furnace-adjacent air bypass + filter (particularly relevant for those of us with access to our own fans/furnaces).
The idea, as I understand it, is that a furnace can be modified by an HVAC specialist to send a portion of the air through a low-flow bypass duct containing a HEPA filter (or some other high-MERV-rating filter). This highly filtered air is, of course, combined with the less-clean air that passes through the low-MERV (standard) furnace filter before being delivered to ducts/rooms. This enables filtering of air for the entire living space without the need for an air purifier (a large plastic box containing future e-waste) in each room where clean air is desired. One obvious shortcoming of such a system is that in-duct/in-room sources of particulates (including concentrated bursts of particles from things like cooking) might be harder to combat. I don't know whether such a system can reduce particulates to levels commonly reached with in-room purifiers.
Yes. The results of this pilot randomized controlled trial (the first for vitamin D and covid, as I understand it) from Spain were astounding. Patients were given vitamin D supplements during their hospital stays. Of those who received the supplements, only 1 of 50 (2%) required ICU care, while 13 of 26 (50%) of the patients who did not receive supplements required ICU care (and two died). 2% vs. 50%!
Vitamin D supplementation is a low-risk, low-cost, side-effect-free (hard to OD) intervention. I see no reason governments should not encourage vitamin D supplementation (or, better yet, actively enable it via distribution of supplements as in the UK...at least during hospital stays). If it turns out that subsequent RCTs disprove the effects (despite the mountain of retrospective studies that show correlations in vitamin D levels and covid case trajectories), what harm will have been done?
The idea, as I understand it, is that a furnace can be modified by an HVAC specialist to send a portion of the air through a low-flow bypass duct containing a HEPA filter (or some other high-MERV-rating filter). This highly filtered air is, of course, combined with the less-clean air that passes through the low-MERV (standard) furnace filter before being delivered to ducts/rooms. This enables filtering of air for the entire living space without the need for an air purifier (a large plastic box containing future e-waste) in each room where clean air is desired. One obvious shortcoming of such a system is that in-duct/in-room sources of particulates (including concentrated bursts of particles from things like cooking) might be harder to combat. I don't know whether such a system can reduce particulates to levels commonly reached with in-room purifiers.
Thoughts/adecdata on such setups?