Paper Clay Air Humidifier | Hacker News Reader

Paper Clay Air Humidifier

maximelouis.com

99 pointstonymarks71 comments

This is an art project and nothing more.

Humidifying only 600 square feet, the size of a studio apartment, takes about 5 gallons of water per day in winter. [1]

The reservoir on this object looks to be no more than two gallons, and I would be truly shocked if it requires even daily refilling. If it actually moved enough water to make a difference, it would be a fundamentally flawed design in requiring multiple complete fillings per day, carting entire gallons to it (as you can't simply take the reservoir to the faucet). In fact however, I would be shocked if it made any measurable difference at all.

It speaks volumes that no information about the rate of water consumption and no measurement figures of RH are present on the page.

1: https://www.generalfilters.com/support/humidity-calculator.h... (settings: St Louis MO values for outside temperature and humidity. Inside 74, 50%, 8' ceilings, standard 0.5 air changes, 1 fireplace)

I think it would depend a lot on how much air is moving over it, and the temperature of that air. The surface area of it is pretty large (the whole thing is pretty ginormous also...). The reservoir size is an issue.

I share skepticism about this being used in any serious way. An ultrasonic humidifier is going to be smaller, probably cheaper, and run laps around it in terms of output.

For a similar surface area I think you could just fill your bathtub to an inch deep and wait for it to evaporate. You'll wait a long time, and your bathtub will get gross, just like this object will.

And with the point being power-free, the air is going to be static or nearly so around the object (or bathtub). If it's supposed to get a boost from moving air from a forced-air furnace, that's cheating -- because in that case you could just install a similarly passive flow-through humidifier on that same furnace and be done with it, save perhaps an annual pad change. Many use no power, just the same "capillary and evaporation" as this - except with actual calculations underlying their specifications.

A word of warning: ultrasonic humidifiers used with tap water create high levels of indoor air pollution: https://www.researchgate.net/publication/51859262_Indoor_par...

Disclaimer: I work for a company that makes low-cost air pollution sensors.

Debatable whether salt crystals are considered air pollution or simply a problem with the specificity of the PM2.5 definition. Note that this isn't a problem with using distilled water, which is recommended for all humidifiers.

It's not just salt though. In some countries, the tap water isn't safe to drink, so it's probably not safe to breathe.

Also, as another poster pointed out, humidifying a large room in winter requires several liters of water per day. The cost of distilled water would quickly dwarf the cost of the humidifier itself, so other types of humidifiers besides ultrasonic (namely evaporative ones, where the main danger is mold, which distilled water doesn't help you with) are more economical.

Not to mention ecological. I mean, in Poland, I can't find any sensible source of distilled water other than buying 5L plastic bottles of it. I've briefly looked into devices that could make distilled water, but all that I've found was some industrial-grade hardware that costs more than reasonable for personal use.

I have a small under-sink reverse osmosis system for that. Was ~250€. I think it is made in Poland. There are several like that around.

Which company? I'm interested in these sensors.

Kaiterra. Our main consumer product is the Laser Egg.

When I finally got a hygrometer I was amazed at how useless the powered one gallon air humidifiers are. They often can’t raise the humidity percent a single point with the hygrometer right by it in my rooms.

If you want to really humidify a room it takes a big industrial sized unit. They had them in the rooms in our Colorado Airbnb cabin and they were totally necessary in the dry mountain air if you didn’t want to wake up in pain from dried out mucus membranes. Very loud and used many gallons of water in a single night.

I have a rather small Honeywell cool mist that works well. I use it in our bedrooms and have taken the humidity up 20% easily. This is in the mountains where it's drier than the desert in the winter.

They ‘cheat’ a little by lofting liquid water which then evaporates. We have a water softener and the cool mist humidifier left a smoke-like particulate floating in the air (i think it was either salt from the softener or minerals from the water)

Yes, that's the minerals in the water. Using distilled water prevents this.

I discovered this when doing a post-assembly indoor test of a Luftdaten air quality sensor I built[0]. I kept it running for few hours and then looked at the data, and saw some ridiculously high levels of PM2.5 and PM5 in the evening. I've decided to investigate it. Over the next two days, I figured out that the increased levels happen at times when our air humidifier is running, which led me to discover that those ultrasonic air humidifiers essentially atomize everything that was mixed with/dissolved in the water - and we were using filtered tap water with ours. With distilled water in the humidifier, the sensor did not show increased particulate levels.

We've mostly stopped using the humidifier now, because I can't find a source of distilled water that doesn't involve buying plastic bottles.

[0] - https://luftdaten.info/en/home-en/

I've encountered the same issue (high plastic bottle waste along with high cost). Short of boiling your own water outdoors to avoid polluting the indoor air, it's challenging to find a source for bulk distilled water.

Boiling your water indoors will humidify the air.

Yes, and it will also release the impurities/minerals into the air, which is what we're trying to avoid by using distilled/boiled water.

I live in an area with very hard water (around 300ppm), and the evaporated minerals are very visible in the air (and it leaves a white residue on the surrounding area).

> I live in an area with very hard water (around 300ppm)

Tangential, but being curious how hard that was relative to mine led me to discover that Thames Water (i.e. only useful to anyone reading in London) has a pretty good page at [0] - a summary on the site itself but the PDF is really worth a look, lots of numbers. Maybe it's a regulatory requirement, but I wouldn't have expected it to be so easy to get so much information from them about my specific (it serves many districts in and around London with different sources and equipment) water supply.

[0]: https://www.thameswater.co.uk/help-and-advice/water-quality/...

It's actually quite common for water authorities to publish quite detailed analyses of the water they provide. Doing such analyses is a core competency of being a water authority and, since they are mostly publicly owned, then published for consumers, often at a fairly detailed level.

> water authority and, since they are mostly publicly owned

Not here:

https://en.wikipedia.org/wiki/United_Kingdom_water_companies

(E.g. Canada Pension Plan, Morgan Stanley, Hong Kong based investment trust)

As I said, it may be a regulatory (Ofwat) requirement, but it isn't just a public body doing right by its citizens.

Interesting anyway, not that much of it means anything to me. Though apparently if/when I try brewing beer again I should add some magnesium. (It even lists the range that's helpful as a yeast nutrient, and above which contributes unwanted taste.)

Boiling water will not get much of the minerals into the air. This is why distillation works.

Would filtering it first help with that?

Yes, my humidifier actually has filters you can buy, but it's a bit cost prohibitive (around $20/filter and with the hardness of the water they only last about 3 weeks).

I just use filtered water from my fridge or from my Brita. Haven't noticed any nasty build up in the humidifier or any hazy production. The larger Honeywell I use in the master bedroom is the top fill which is designed as filter free.

Rain is essentially distilled water (evaporation from terrestrial water bodies and then condensation in the atmosphere). It picks up some contaminants in the atmosphere and some dissolved gases when it condenses but it's going to be mostly free of minerals (i.e. not be hard). So collecting rain water is one source of bulk 'distilled water'.

Depending on where he lives, that might actually be illegal to do.[1]

[1] https://bestlifeonline.com/illegal-collect-rainwater/

We also have a air purifier that watches for particulate and they would battle each other constantly lol.

Moved to an evaporative humidifier, my air quality appliances now operate in peace.

Oooooh, so that is the cause of my apartment being hazy?! Just moved to a new place, air humidity can get around 10% and since I don't enjoy being tazed by my sofa I bought a small humidifier from Amazon, both I and my wife noticed what seems to be a cloud in our living room.

If it's a cool-mist type humidifier, definitely.

I grabbed an evaporative one from the local big box hardware store and zero 'smoke'. You should get some bacteriostat and you'll have to replace the paper elements every now and again, but it's way better.

This may also indicate insufficient air exchange (high CO2 level) in your bedroom.

When I was a kid in the eighties we had these huge “console” humidifiers that held maybe 15 gallons and had a rotating belt and a big fan. Seems like they stopped making these in the nineties in favor of the useless tiny things.

My grandpa used to have the exact same thing.

You can still buy smaller versions of, they are called 'evaporative humidifiers' and use a paper element with a fan. They are slower to adjust humidity but leave zero haze.

> 600 square feet

Maybe most people already know this, but I only learned it recently: you can go (approximately) from sqft to sqm by dividing by 10, presumably because 1m = 3.28ft and 3.28 squared is ~10. So 600sqft is about 60sqm (55.7)

It's a bit easier if you think "the other way", so 1ft ~ 0.3m or squared it's 0.9m2 so, divide by 10 and take 10% off and you get the ft2 -> m2 (or multiply by 10 and add 10% for m2 to ft2)

Still approximate

> Humidifying only 600 square feet, the size of a studio apartment, takes about 5 gallons of water per day in winter.

This heavily depends on the ventilation as well. With ERV HVAC[1] it is much easier to keep higher humidity level as some of the moisture is reintroduced in the heat exchanger.

[1] https://en.wikipedia.org/wiki/Energy_recovery_ventilation

Correction: This is a "hipster" art project

Shouldn't even be on Hackernews

60m² is very large for a studio appartment.

Based on your numbers, 1 gallon would be enough for a 10m² bedroom.

I don't know what the site author did to make it so the zoom button doesn't adjust the font size but I implore anyone similarly tempted: please don't do this.

I think it's the viewport "user-scalable=no" meta tag value?

That's a terrible thing to do to people who have poor or low vision, and the font size is small enough that it's almost a problem for people who have otherwise decent vision but require reading glasses!

It's worse. The size of the text depends on the height of the window. Resize the window and it quickly becomes illegibly small.

If you're using chrome or it's derivatives, install the extension ZOOM TEXT ONLY.

For Firefox no extension is needed on desktop. Google how to do it. For Android Firefox, I use the add-on called LEGIBILITY.

There's built-in "Reader View" in Firefox (both desktop and mobile).

https://support.mozilla.org/en-US/kb/firefox-reader-view-clu...

Be really careful with humidifiers.

I cranked mine up too much and it caused a mold issue in my home, and mold in my home caused me health issues.

I don't think it would be possible for a passive unit like this to do such a thing.

With ultrasonic or warm mist (steam) humidifiers you can over-humidify the air.

One one hand infection experts say humidity protects you, on the other hand they say most types of humidifiers are disease incubators. On top of it it’s a fact that humidifier additives effectively are chemical weapons that works on humans at lower concentrations than it works for pathogens.

We’re sort of in a bind — so how are we supposed to have safe air? 6-hourly bleached, heater based humidifiers running off the tap?

Install a reverse osmosis system under your sink, and use that to fill the humidifier.

Nothing's going to incubate in that.

Heat your homes a little less. There is a big humidity difference between an 18° room and a 24° room.

I was sick quite often in the past - what helped me was

a) tuning down the room temperatures to ~21°C in winter

b) drink a lot of water

The last time I got really, really sick was in 2017.

The rule of thumb is that if your humidifier is causing condensation on your windows, then you have condensation inside your walls as well, which is the necessary precursor for mold.

We have this whole house humidifier installed in our furnace: https://www.aprilaire.com/whole-house-products/humidifier/mo... It has a remote temperature sensor you install outside, then it automatically adjusts the humidity based on the outside temperature to keep it under the mold-growing level.

This is a very good idea, it uses no external energy and can potentually last forever. It’s a very simple and efficient thing. The only thing that I wonder is if this could be washed and whether mold can form in the pores. My ultrasonic steam humidifier can be easily cleaned but it makes an audible sound that happens to not bother me.

What I was wondering too. Especially with the rough surface and slits in the back. Maybe putting a small amount of Bleach in the water would prevent it.

Completely unrelated the content - which I cannot read due to the tiny font, but can anyone recommend a plugin/extension for Firefox that can take webpages like this and trim out the excessive whitespace? I cannot read the text and increasing the size (control-+) just makes the white space bigger too.

Here’s an idea I had for a humidifier. It simply tumbles thousands of tiny beads through tumbler with water at the bottom. Since the sheer number of small beads creates a huge surface area you’d get a bunch of evaporation.

Cool right? Feel free to use this idea as prior art.

There is a similar concept where you have a stack of plastic discs half submerged in a water reservoir. The axis of the disc stack sits parallel with the surface of the water. The discs are rotated so their surface is always wet. Air is blown over them. This passively humidifies the air, and won't over-humidify since as the RH rises the amount of water that will passively evaporate goes down. These units are sometimes also called "air washers" since small particles can get stuck to the surface of the wet discs and come off in the reservoir. I've owned two, and can confirm they do pull stuff out of the air.

https://duckduckgo.com/?q=venta+air+washer&iax=images&ia=ima...

https://i.ebayimg.com/images/i/282057161748-0-1/s-l1000.jpg

Yes but energy intensive.

Couldn’t be worse than the ones that heat up water to make steam.

That would need to be assessed, I think.

Is this actually practical or is it some art project? It looks like the latter.

HVAC engineer here. Hard to tell as they don't provide any details on the rate of evaporation. One issue for ongoing use would be scale buildup - particularly in areas with hard water. Probably the best option would be to fill it with demineralized or RO water.

Pretty! A bucket full of perlite and half full of water does a decent job too. The trouble lies in keeping the water topped off and keeping it clean, as with anything else evaporative.

Depending on your water supply, this design may fill up very quickly with mineral deposits and stop wicking.

This actually relates to my question, do capillaries clog?

They sure can! You can do an experiment with a paper towel hanging over the side of a bucket that has water in it. Check out how quickly it clogs up.

To mildly humidify my baby son’s room without having to maintain a humidifier, I use a towel soaked in water, draped over a chair, with a fan pointed at it overnight.

I've used this in the summer to cool down in apartments with no AC.

But is it actually effective for humidification? The top comment mentions that it takes 5 gallons per day to humidify a small studio apartment under ideal conditions...

Well, 600 square feet can be a studio but it's by no means a small studio. It's enough space for a perfectly comfortable 2 bedroom apartment. (Or 3 if you squeeze.)

For a single room, if that towel holds a gallon it should work fine for an overnight humidification job.

It's very effective for humidification, the difference is immediately noticeable. The room is probably 100 square feet, I'm only humidifying it at night, so by your calculation it should take only about half a gallon of water which is probably what fits on a towel give or take.

get an open top aquarium, it's much more rewarding and efficient way to increase the humidity of a room

Is this the same thing as a swamp cooler?

No, a swamp cooler would actually work.

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