u/runcyclexcski

Just wanted to share quick test results of a VENTA LW15 humidifier I bought from the manufacturer. I understand that currently there are many copies of it available from Asia, so maybe this will be used for someone on this sub. I used basic testing equipment for the tests -- gauges and anemometers.

I found that the only room in which the LW15 could move the humidity up (by 10% in a couple of hours) was 3 x 2 x 2.4 m = ~14.4 m (~120 sq ft). The key is that the room had to have no ventilation (a gasket-sealed door). Any minimal air exchange/ventilation relevant for human comfort ( removal of CO2, supply of O2) -- e.g. 0.5 air volumes per hr -- made the humidity increases by the LW15 negligible (not even 2%). This is disappointing, b.c. the unit is claimed to be "optimized" for 25m^2 (~270 sq ft). I guess if one slept in a sealed 25m^2 room, with no ventilation, it might move the humidity up. And half of that humidity would come from one's own breath.

Looking at the fins of the drum, they seem to be made of polypropylene which looks quite hydrophobic and the water rolls right off the fins back down. If they made the fins of some hydrophilic material (metal, spongy material etc), it might have worked better.

I missed the amazon return date, so I am stuck with the Venta. Maybe will use it in a storage unit.

Thanks for reading!

I see that many folks here use the Smartmi Evaporative unit (the one with the spinning disks). May I ask if the disks are dishwasher safe for a deep wash, and if you have observed issues with plastic smell from it? Ideally, I was hoping to find a unit that works by the "spinning disk" principle, with disks made of 304 steel, but can settle for the Smartmi if it's easy to clean and does not smell.

Edit: The thing still works if I do not install any apps -- correct? I do not care for any smart features, as long as the motor spins when the tank is full and stops when it's empty.

Thank you all in advance!

[I already have boiling humidifiers, they work great in the winter. But using them in the summer to counter-act the dry air from the AC is counter-productive -- energy and temperature-wise].

Has anyone heard of this DIY pollen-sampling device or tried to make one? I just read this 2025 paper, and a google search for the main keyword only returns the authors' CVs.

https://www.hardware-x.com/article/S2468-0672(25)00090-2/fulltext

Commercial devices cost from a few thousand (Hirst/Bukrard) to tens of thousands (Swiss Poleno etc), whereas the authors claim they made theirs for ~$150. The correlation with commercial units is claimed to be excellent.

I am thinking to build this thing and to do sampling at home during the high grass pollen season, to test how good my 24/7/365 forced ventilation+HEPA system is. The filtration lowers the concentration of PM2.5 20+ fold compared to the outdoors, but I've never measured how good pollen filtration is. It would also be nice to have a "positive control" though, e.g. by an independent measurement with a loaner Hirst etc.

Has anyone tried to use indirect evaporative cooling in their tiny house? By indirect I mean the one that uses two independent contours for the air and thus does not raise the humidity. I am looking to lower the temp by a few degs during heat waves that last up to 2 weeks. It does not get above 60% RH where I live, so I may have a chance. A google search gives some (not many) results, but all systems I found look enormous/industrial.

I have an old (20+ years) BofA account and I've moved to Europe a few years ago. Transferring the funds from the account to my european bank has been getting more difficult each year. Now they require a US cell number, or a USB security key.

Has anyone been able to register a USB key outside the US? If yes, can you recommend one? I do not want to get the key and then be stuck in the registration process at some impossible step (like a US cell number). YubiKey comes up as top google result, but BofA is not mentioned on their web site.

I wonder, once I manage to move the funds, if I should close the account -- before they invent yet another "added security feature" to prevent me from withdrawing funds.

Thank you all in advance!

I am looking to join ends of a spring steel band (1.4310) to make a belt. Sort like a blade of a vertical band saw, but not for cutting; rather the band will be used for a small conveyor. The band is 0.8-1.0 mm thick (1/32... 0.04") and 25 mm (~1") wide, and will be driven over 300 mm diam (~12") pulleys.

Is it realistic to retain the flexibility and the tensile strength of the band across the seam? The flexibility is most important, but I can tolerate a 2x reduction in tensile strength.

I do not weld, thus, I will need to seek local help for this small job, so I need to learn what questions to ask the welder. If this is doable with a hobbyist setup, I may consider buying an apparatus in the future (I've taken basic classes before).

https://preview.redd.it/z829zwuquxxg1.png?width=511&format=png&auto=webp&s=03191c87203d9b00a245bb589702155a0eef07c5