My libertarian-ish/yimby sensibilities don't love it. It also seems to already be a feature of many US states - eg I hold a NJ master HVAC license - and I don't see it as have much benefit thus far.

Thanks!

Thanks!

Re 1) This is probably a factor, but I'd guess it would have low tractability and even if completely corrected would have limited impact. This was the basis for CheckMe that I mention in the post, and since then there are many technological innovations that make crosschecking really simple but have limited impact. For instance, if properly implemented, digital instruments integrated into platforms like measure quick would fix a ton of problems, but I don't see much happening irl with this. 

2) Exactly! Not sure on test, but operating within parameters doesn't seem like a crazy ask.

3) Yes, that's definitely on of the points I was trying to make. If we're choosing between systems that have the theoretical capacity to work in a highly optimized way but are failure-prone and opaque vs systems that work sub-optimally but are readily verified and less failure-prone then I think we should choose the latter.

Thanks! Tbh I was pretty close to cutting that part due to superfluity so I'm happy to hear you found it insightful. 

I agree that there are potential areas where drawing from a wide range of backgrounds could be better than the current structure. Tbc, I don't want to overrate this and it's likely highly domain specific. Long before this I started a piece on the widespread conflation of physical skills vs knowledge that characterizes much of the collapse recovery focus. This also also seems like a potential white collar silo phenomenon.

Seems right! I think some of the biggest opportunities are improvements to technology that anticipate and correct for downstream failure. To some extent sophisticated manufacturers already do this - eg constant airflow fans installed in restrictive duct systems tend to fail prematurely. Many of Mitsubishi's air handlers now limit external static pressure to .8 inches of water column, I suspect in response to these high failure rates.

ctrl f "external static pressure"

https://www.mylinkdrive.com/viewPdf?srcUrl=http://s3.amazonaws.com/enter.mehvac.com/DAMRoot/Original/10006\M_SVZ-KP-NA_Install_MD-1404-K021_V_4_2022.pdf

Thanks so much for doing that! 

Florida is a challenging environment. Right-sizing (manual J) of cooling equipment is especially important in humid climates. In over-sized systems, short run times tend to satisfy the thermostat but not properly dehumidify, because this takes much longer. In addition, Florida has many duct systems in unconditioned attics, and duct leakage draws humid air and contaminants from outdoors. If you have a system in an unconditioned attic this should be at minimum fastidiously sealed. Many people in building geek circles feel that conditioned attics are warranted, but my experience suggests that these aren't often cost-effective retrofits: https://buildingscience.com/documents/building-science-insights-newsletters/bsi-119-conditioned-unconditioned

The final 2 considerations are 1) turning the AC fan to the lowest possible speed that can be sustained without freezing the indoor coil. This is generally ~325 cubic feet/minute per nominal ton of cooling. And 2) adding supplemental dehumidification. Target <55% relative humidity at ~75F. This can be a simple standalone dehumidifier piped directly to a sump or condensate pump.

For filtration, recommendations largely in line with pandemic seem fine for small particulate too - i.e. MERV 13 filters in centralized systems. IAQ monitors can be great tools as well!

Reach out directly if you need anything!

Thanks! I'm not totally clear on what curate means in this context but am definitely amenable to editing for clarity!

Those are very valid criticisms. Before posting I felt there were two major shortcomings. 1) It's argumentative (vs scout mindset), and  2) the claims aren't well verified. Taking a different approach with 1) felt disingenuous, but 2) remains problematic.

I'm not aware of any quality empirical work directly focusing on the shortcomings of this workforce. I think this is partly due to a significant disconnect between people working in public health and people working in the industry. So when public health people encounter this argument they say something like "yes we'll need more training for technicians" which isn't really the claim I'm making (an important person from a PH thinktank actually just did this in response to this post lol). I'll try to better corroborate the claims or come up with more readily documented ones. Ultimately I think we'll still be left with something tantamount to a firehouse of anecdotes, which readers will have to decide whether or not to take at face value.

I can definitely better explain Manual J. I'll also give some thought to illustrating the school building manager point more effectively. 

Feel free to edit the headings however you see fit. I'll look for that feature if I make any future posts.

Is it OK if I share the original draft with you? Thanks!

Thanks Rachel!

Exactly! I'm not making observations that people in the industry aren't aware of. On the other hand, I've yet to see any sort of acknowledgement that this might feature in disease reduction decision-making. It's made the last 3 years a bit surreal, tbh.

Thanks! I just signed up. Very curious to see if this is a feature of other technical areas.