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Big Ass Fan’s Clean Air System

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Re: Big Ass Fan’s Clean Air System

#61

Post by sargun »

I’m kind of surprised that the people who make those pods at offices haven’t gotten into this.

Heat inactivation is shown to be effective at getting rid of sars-cov-2. Those little pod things could have a cleaning cycle where they heat up to 65C (~150F) for 15-30 minutes.

Add a UV-C light during the cleanse cycle, and you’ve probably got most things. If I were a wework, I would be building these as a place for people to work out of home.

The other thing you can do is put fans that suck air upwards, and then eject it outside, and replace the air inside with (clean) outside air.

You could build larger units for places like restaurants, where they can fit 4-6 people.

Part of me finds the idea of a “private dining pod” kind of nice — but real estate prices have never made it reasonable for restaurants to do.

Re: Big Ass Fan’s Clean Air System

#62

Post by deegles »

falcolas wrote: post #58
deegles wrote: post #55

Can someone please point me to actual studies validating the "ion" generation stuff? My dad insists that a wearable ion generator he bought works "because it's made by NASA" (it's not) but I can't find studies that validate the technology. Thanks in advance!

Veratasium dug into it in quite a bit of depth. TL;DR: It doesn't do much (if any good). Worth watching, regardless. https://youtu.be/ZQ--scjcAZ4

That's a really good video, although it seems to focus on the health benefits of direct ion exposure. I like how he methodically breaks down the claims and the purported science behind them. I would like to know more about the claimed Covid-related ion effects.

Re: Big Ass Fan’s Clean Air System

#63

Post by BiosElement »

amelius wrote: post #40
bsder wrote: post #37

Earlier quoted context omitted.

Isn't a big ass fan just boring old tech which is easily replicated ...? Just because something is easily replicated doesn't mean I want to spend the time doing it. And, as a side note, I suspect you underestimate the engineering behind those fans. Making a large fan which doesn't vibrate or make annoying noise is non-trivial.

Ok, I agree, but a similar thing can be said about vacuum cleaners, coffeemakers, washing machines, ... you get the point.

Indeed, and there seems to be plenty of competition in those markets for quieter, more reliable vacuums and washers anyway. I'm not seeing how that changes the point though, unless I'm missing something.

Re: Big Ass Fan’s Clean Air System

#64

Post by danans »

tpmx wrote: post #56
danans wrote: post #53

Earlier quoted context omitted.

The question with that system is: where is the replacement air coming from? To be effective for disease particle controls, it needs to come from outside, otherwise you'd just be sucking dirty air from the rest of the building into the classroom - or even worse: backdrafting CO2 and CO from any combustion appliances within the building envelope. You can achieve a clean air supply by opening another window in the class…

Also: How do you make that system work in the winter?

A heat recovery ventilator works fine in the winter. Its whole purpose is to introduce fresh air into the conditioned space while preheating it with the heat in the dirty exhaust air stream.

Re: Big Ass Fan’s Clean Air System

#65

Post by jessaustin »

danans wrote: post #64
tpmx wrote: post #56

Earlier quoted context omitted.

Also: How do you make that system work in the winter?

A heat recovery ventilator works fine in the winter. Its whole purpose is to introduce fresh air into the conditioned space while preheating it with the heat in the dirty exhaust air stream.

HRVs have been designed to exchange heat, and ERVs to exchange heat and moisture, but have either specifically been designed not to exchange virus particles? One wouldn't want to make any assumptions...

Re: Big Ass Fan’s Clean Air System

#66

Post by danans »

jessaustin wrote: post #65
danans wrote: post #64

Earlier quoted context omitted.

A heat recovery ventilator works fine in the winter. Its whole purpose is to introduce fresh air into the conditioned space while preheating it with the heat in the dirty exhaust air stream.

HRVs have been designed to exchange heat, and ERVs to exchange heat and moisture, but have either specifically been designed not to exchange virus particles? One wouldn't want to make any assumptions...

At least with heat recovery ventilators, the air streams do not mix at all. Unless the virus finds a way to penetrate the metal fins of the heat exchanger, it should be completely fine.

Re: Big Ass Fan’s Clean Air System

#67

Post by msandford »

d13 wrote: post #54
Devils-Avocado wrote: post #52

Airborne transmission of COVID is sexy, requiring solutions like this, and individual impositions like wearing masks which are easy to police. But I think the more likely spread of COVID is from mundane surface transmissions. One of the 'mystery' COVID cases in New Zealand was eventually tracked to people touching the same elevator button about an hour apart, for example. Same here in Europe - everyone is wearing mas…

Stairs, or press buttons with tip of key. Entrance Door with foot or paper tissues. If 1 in 200 have Covid, 50% chance elevator has been recently infected.

First it was the bats and the pangolins who gave it to the people. Then we gave it to the minks who gave it back to us, mutated. Now even the elevators can catch covid?! What's next? I sure hope it doesn't mutate and hop to vegetables or else we won't be able to eat anything!

Re: Big Ass Fan’s Clean Air System

#68

Post by craftinator »

Barrin92 wrote: post #32
rubidium wrote: post #13

Earlier quoted context omitted.

Anything but. They’ve got validated 3rd party studies. Plus they’re a real Hardware product company with a long history of quality product. Not some Silicon Valley “ai magic virus eater”.

Those 3rd party studies seem like a pretty big joke >"The test unit was installed in the center of the test chamber with a blade height of 93” from the floor. The test chamber measured 10' x 10' x 10' (3m x 3m x 3m) and a microbial suspension was aspirated into the chamber. Air samples were taken from the test chamber once the unit was turned on, and then at client specified intervals (0, 5, 10, 15, 20, 30, 45, 60, 9…

> Test that thing in a restaurant or a hair salon with a dozen people continuously interacting in it and then test the quality of the air

That's not how scientific studies work.

Re: Big Ass Fan’s Clean Air System

#69

Post by catherd »

Barrin92 wrote: post #32
rubidium wrote: post #13

Earlier quoted context omitted.

Anything but. They’ve got validated 3rd party studies. Plus they’re a real Hardware product company with a long history of quality product. Not some Silicon Valley “ai magic virus eater”.

Those 3rd party studies seem like a pretty big joke >"The test unit was installed in the center of the test chamber with a blade height of 93” from the floor. The test chamber measured 10' x 10' x 10' (3m x 3m x 3m) and a microbial suspension was aspirated into the chamber. Air samples were taken from the test chamber once the unit was turned on, and then at client specified intervals (0, 5, 10, 15, 20, 30, 45, 60, 9…

That test procedure sounds similar to the standard test for CADR (ANSI/AHAM AC-1-2015), which uses a 1008 square foot test chamber and measures the ability of an air purifier to deliver clean air.

CADR is the product of air flow and fractional removal efficiency, and it's the industry standard value if you want to compare performance of one air purifier to another. The CADR test usually makes separate measurements for dust, pollen, and smoke (particulates). It looks like they adapted the normal test procedure to measure the reduction in live/viable microbes.

However, in a few minutes of looking at their homepage I don't see anywhere they list a number in CFM of purified air, which is what CADR measures.

https://cfpub.epa.gov/si/si_public_file_download.cfm?p_downl... [Appendix A]

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