Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Permeable materials in homes act as sponges for harmful chemicals: study

news.uci.edu

Post reply on HN
Print view View original

51–60 of 114 posts

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#51

Post by esperent »

b112 wrote: post #16
cameronh90 wrote: post #11

Earlier quoted context omitted.

The challenge with opening the window isn't even the cost - which is substantial - from about £250/month to £400/month if I have my windows open even a little bit. The bigger challenge is with my windows open, my heating just can't even keep up! It'll be maxed out and only 18c. I do the German-style luften twice a day, but if our interiors are just absorbing the compounds and releasing it when the windows are shut, t…

Get a heat recovery exchanger. https://natural-resources.canada.ca/stories/spotlight-energy...

Good advice if you can do it, but this isn't possible for most people, for example if you're renting or you're in an apartment.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#52

Post by musha68k »

I'm asking myself if building a DIY setup or buying something like Airthings Wave Plus will actually track these compounds at decent accuracy - and if anyone here has gone down this rabbit hole for family health?

From what I've gathered, consumer devices hit acceptable accuracy for CO2/temp/humidity but PM2.5 is hit-or-miss, and VOC readings are more "relative change indicators" than absolute values..

DIY with Home Assistant is more work/fun yes but again only gets similar accuracy AFAIK (with potentially better automation)..

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#53

Post by musha68k »

elric wrote: post #49
coder543 wrote: post #13

Earlier quoted context omitted.

Outside air isn’t a panacea. There is often plenty of pollution right outside your window unless you live on an idyllic beachfront property. The humidity level outside is also rarely what you want in your home, whether it is too high or too low. Much better than cracking a window is the use of ERVs (energy recovery ventilators) and air filters on the incoming air. An ERV is a fairly simple device that exchanges air w…

I installed an ERV system in my very small and very old home. It was quite a bit of work, but nothing terribly difficult. Finding a suitable spot for the ERV unit was the biggest challenge: it is quite bulky and not silent, and you need to be able to route ducting to it from all over the house. It's easily the favourite thing in my home. It filters the outdoor air, reducing pollen and mosquitoes. It keeps out excess…

Could you share which one you installed and under which circumstances? I'm running two mobile HEPA air filters; not very efficient nor very effective I'd assume.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#54

Post by amluto »

hylaride wrote: post #27
2rsf wrote: post #2

The article doesn't seem to have immediate actionable recommendation, and is mainly a brick in a wall that can lead (or not) to better design decisions. One unclear point for example is what happens with the deposited toxins, how hard is it to clean them? are they transferred by touch?

Well, it's a classic research paper. They're essentially only supposed to report findings. If you live in a house with central HVAC, a decent, regularly replaced filter will help a lot (make sure to only use full blown HEPPA filters if your furnace supports it otherwise you'll have all sorts of airflow issues). Otherwise you can buy air purifiers. The study measured smoke (cigarette and wildfire) as well as insectici…

The study is about VOCs. You’ll want a carbon filter, as even a HEPA filter won’t do much.

Also, don’t put a HEPA filler in your HVAC return — not only is it unhelpful overkill, it will have excessive static pressure drop, thus wasting power, increasing noise, reducing airflow, and potentially damaging the blower. Use an appropriate filter in the MERV 13-16 range.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#55

Post by owenversteeg »

coder543 wrote: post #32
encom wrote: post #31

Earlier quoted context omitted.

Don't leave your windows open all the time. Open them for 5-10 minutes at least once a day. Heating air is cheap, it's heating all the other mass in your home that's hard, so don't let it cool down. If you live somewhere uninhabitable like Texas, change heating for cooling.

> Heating air is cheap, it's heating all the other mass in your home that's hard Is the air cheap to heat? Even if it were, that still wouldn't solve the other issues that were mentioned.

The GP comment is technically correct, if somewhat incomplete. A 40 m3 room (about 14’x14’x8’) has about 50kg of air in it; that’s only ~300 Wh to heat every molecule of it by an entire 20C. The thermal mass of the other things is orders of magnitude larger.

The reason that I consider that explanation somewhat incomplete is the behavior of the air and the embodied energy. Imagine it’s winter, the exterior air is quite dry, and you open a window. You will easily lose a large amount of moisture, making the air uncomfortably dry. So you turn on a humidifier, but that will cool the room further with the evaporation of water. You also have to consider convective heat transfer. The fast-moving air is quite good at transferring heat to the outdoors. So, even if you don’t care about humidity, you will lose a lot of heat through convection.

But yes, strictly speaking, the thermal mass of the air is very low in most structures and situations.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#56

Post by coder543 »

sfilmeyer wrote: post #41
coder543 wrote: post #13

Earlier quoted context omitted.

Outside air isn’t a panacea. There is often plenty of pollution right outside your window unless you live on an idyllic beachfront property. The humidity level outside is also rarely what you want in your home, whether it is too high or too low. Much better than cracking a window is the use of ERVs (energy recovery ventilators) and air filters on the incoming air. An ERV is a fairly simple device that exchanges air w…

Can you link an example of a window unit ERV? I tried searching briefly, and came across some folks hacking together units to make them work with windows or adding their own ducting, but nothing analogous to a simple window air conditioning unit. As a renter of an apartment in a very much not modern home, I don't really see anything that seems like it would work.

http://www.purifresh.com/erv.html

https://swervair.com/

A couple examples I see on Google. I'm not advocating for any of these, because I have no idea if they are any good, but I see no technical reason an ERV couldn't work as a window unit. Maybe it's an underserved market and someone should make a business out of that.

A much more DIY example that's probably closer to what you were talking about with "hacking together" a solution: https://www.mychemicalfreehouse.net/2023/10/window-mounted-p...

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#57

Post by J_Shelby_J »

jbd0 wrote: post #36
crazygringo wrote: post #3

The more we study it, the more we learn how harmful the air inside our homes is. That's why fresh air is key. Crack a window or two open. Buy an air monitor that monitors CO2 (good proxy for overall freshness), VOCs (sometimes these build up much faster than CO2), and PM2.5. If CO2 or VOCs are high, open windows more. If PM2.5 is high and coming from outdoors, turn on an air filter. Yes, this means your heating and c…

I built a window vent with a variable-speed computer fan and an esp8266 that communicates with a CO2 monitor and raises the speed when the CO2 gets too high. I have a very fine mesh on the window screen that's designed to filter out pollen and dust. It works really well. I usually only turn it on at night, because that's when my wife and I are both in the room and the CO2 can really build up.

I use an ikea air filter that just so happens to fit perfectly in the window + a smart outlet and co2 sensors.

I’d like to do a custom build like you so the fan speeds are variable.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#58

Post by bartread »

capitol_ wrote: post #42
cameronh90 wrote: post #11

Earlier quoted context omitted.

The challenge with opening the window isn't even the cost - which is substantial - from about £250/month to £400/month if I have my windows open even a little bit. The bigger challenge is with my windows open, my heating just can't even keep up! It'll be maxed out and only 18c. I do the German-style luften twice a day, but if our interiors are just absorbing the compounds and releasing it when the windows are shut, t…

Why do you need it to be cooler than 18c?

You’re replying to somebody from the UK. They want it warmer than 18C inside. In winter it is typically much colder than this outside so they’re saying their heating won’t get the house warmer than this even if windows are only cracked open.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#59

Post by elric »

musha68k wrote: post #53
elric wrote: post #49

Earlier quoted context omitted.

I installed an ERV system in my very small and very old home. It was quite a bit of work, but nothing terribly difficult. Finding a suitable spot for the ERV unit was the biggest challenge: it is quite bulky and not silent, and you need to be able to route ducting to it from all over the house. It's easily the favourite thing in my home. It filters the outdoor air, reducing pollen and mosquitoes. It keeps out excess…

Could you share which one you installed and under which circumstances? I'm running two mobile HEPA air filters; not very efficient nor very effective I'd assume.

I have a Zehnder ComfoAir Q350. Overall I'm very happy with it. My only regret is not having installed the optional additional filter box. Due to the limited space and the place I've installde it, it's not feasible to retrofit it.

Re: Permeable materials in homes act as sponges for harmful chemicals: study

#60

Post by physarum_salad »

coder543 wrote: post #13
crazygringo wrote: post #3

The more we study it, the more we learn how harmful the air inside our homes is. That's why fresh air is key. Crack a window or two open. Buy an air monitor that monitors CO2 (good proxy for overall freshness), VOCs (sometimes these build up much faster than CO2), and PM2.5. If CO2 or VOCs are high, open windows more. If PM2.5 is high and coming from outdoors, turn on an air filter. Yes, this means your heating and c…

Outside air isn’t a panacea. There is often plenty of pollution right outside your window unless you live on an idyllic beachfront property. The humidity level outside is also rarely what you want in your home, whether it is too high or too low. Much better than cracking a window is the use of ERVs (energy recovery ventilators) and air filters on the incoming air. An ERV is a fairly simple device that exchanges air w…

Yes, consider spores from harmful microorganisms that are released during building work or harmful airborne particles from transport vehicles. Its not as simple as: open the window!
Post reply on HN