Home air purifiers effective for improving indoor air quality?

My spouse had frequent dry coughing problem. Even after taking medicines and cough syrups it didn't go away.
After doing some research, I found that it could also be due to large particles in the air.
The cough went away in a few days after I started using air purifier.

It also helped with my daughter's allergy.

Ideally in a city like Delhi you would keep them running all day. But it's impossible to avoid it fully. My filter has a claimed life of 8500 hours which means 1 year of running 24x7. But it has already clogged up in just two winters (so 6 months max) because the pollution here is so much more than they assumed in their testing.

The air quality in Pune has deteriorated ever since the rains stopped, which is evident by the dust levels inside our house. We could get by with dusting once or twice a week in the monsoons, but now, if we leave our windows open for a couple of hours, we can see a light coating of dust on all the furniture. And, we live in a relatively less congested part of the city.
Sometimes I feel I can taste dust.

Air purifiers definitely help. I can feel, and smell the difference.

The only problem is that for them to be effective, they have to run in a closed room. So, for us, that means we can't use them at night, because we like to sleep with the windows open.
But we use them during the day, and they do help.

When we dust the room, the purifier works in turbo mode.
After vacuuming it generally works at the lowest setting. Which leads me to believe that a room vacuumed with a machine with a HEPA filter, with it's doors and windows kept shut, doesn't necessarily need an air purifier, at least in relatively less polluted cities like Pune.

Renegade said:

With the pollution levels rising, cold/cough frequency increasing and lasting for weeks instead of days, are the home air purifiers helpful at alleviating the situation? And will it make any difference if it is used only at night?

@logistopath - please share your opinion as well.

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Thanks a ton for opening this thread as I had exact same question to the T. Purifier and only at night. My younger one has GERD issues and dry cough that aggravates sometimes and dust allergy too. I too am contemplating air purifier and only for night use.
The AC technician when came to clean AC tells me "itna saara dust....aap windows pura din bandh rakha karo". Cannot do that though.

roadrash99 said:

Ideally in a city like Delhi you would keep them running all day. But it's impossible to avoid it fully. My filter has a claimed life of 8500 hours which means 1 year of running 24x7. But it has already clogged up in just two winters (so 6 months max) because the pollution here is so much more than they assumed in their testing.

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Only if your house is sealed shut you can use all day right? My home has all windows open all the time except at night when bedroom windows are closed as AC is on. So can only use at night.

Renegade said:

At least half a day of clean air should be better than no clean air.

There is my another concern, that even if we keep all doors and windows closed, in high rise apartments there is always wind seeping through those crevices. You can stand near the edge of the closed window and feel the outside air come in. Will put a lot more load on the purifier and hope it does not render it ineffective.

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It won't render it ineffective. You'll just have to change the filters more often.
Anyway, something is better than nothing.

I used it at home during Diwali when my mother was coughing and it went away in a matter of minutes. However, on most days, the air purifier switches to green within minutes, so don't see much benefit of using it during the day, especially with having to close all windows.

Use the AC at night anyway, and it again takes a few minutes for the purifier to go green, so doesn't see much use at night as well.

Only during Diwali, had to keep it on for hours with the window slightly ajar and it struggled to go green.

I have an Mi Air Purifier. The filter is cylindrical. My first filter got clogged up pretty soon, like in 3-4 months. Then I read about washable pre-filters present in other company air purifier.

I thought to create one such pre-filter for mine. I took some old worn out (thinned out) cotton vests, cut them in rectangular pattern and then wrapped it around the actual cylindrical filter before putting it inside the Mi Air Purifier.

The white vests become almost grey-black in under a month. I just remove that and wash it every month.

HEPA filters also have a life span so I change that too but not as frequently as I had to do before because of clogging.

Obviously there will be multiple rooms in the house, in this case one has to buy air purifiers for every room isn't it?
Otherwise it's like "something better than nothing" ?

@Renegade Have you drilled down to a purifier of your choice and what is your max budget? My bedroom is around 10 feet x 10 feet types so I will need to buy as per that.

I am using airpurifier 24x7 in my room. It works well and my allergy symptoms have reduced but not gone ( cant do whole house and cant control outside air). I also use a dehumidifier as we have very high humidity often in Mumbai, esp at night or monsoons.

1) Air purifier does not replace vacuum cleaner ( has HEPA too)/dusting/washing curtains/bedsheet etc. Heavier dust still settles down and needs to be cleared every couple of days ( Mumbai ).
2) Vacuum does not replace air purifier, esp if you have respiratory issues. My prefilter catches a lot of dust and lots of small particles we dont even see and they float and are inhaled otherwise. Smaller particles can cause larger health issues i think.
3) Need to keep windows closed for AP to work. Air still leakes in from window gaps, but if it did not we would suffocate. AP works well with windows and door closed inspite of gaps. Ideally, we need air tight windows and filtered intake.
4) I am using since 6months or so and HEPA filter is working well with good airflow. So life might be decent, but we do need to have a prefilter that you clean up ( can vacuum) every 2-4 weeks.
5) Many AP have prefilter built in, mine does. Then no need to add DIY prefilter.

I am using IKEA airpurifier(STARKVIND) bought for 13k. They had a crazy good deal in diwali(5k) but that is gone. Filter cost is reasonable at 1k and has a decent size.

Renegade said:

Thanks for the useful tip. Should be very useful for larger particles and act as a prefilter. Doesn't it impact the air suction and flow though?

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This was my initial worry too but after a single wrap of vest cloth, I didn't find any change in air flow, nothing scientific method to check, just felt by keeping hand. Then I did a second layer and still couldn't feel much difference.

The inner one also gets somewhat dirty but not as much as the outer one, so I left it with two layers. It is not a thick vest cloth as in Jockey, it is more on the thinner side in the likes of LUX Venus. I hope my answer is helpful

Tracer_Bullet said:

I am using airpurifier 24x7 in my room. It works well and my allergy symptoms have reduced but not gone ( cant do whole house and cant control outside air). I also use a dehumidifier as we have very high humidity often in Mumbai, esp at night or monsoons.

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I am in Mumbai too and we have AC on most of the night. We were of the opinion that AC dries the air so we have a humidifier running entire night in bedroom too. Are we doing wrong? Should we sell Humidifier and instead get a dehumidifier and do we get air purifiers with dehumidifiers built in?

raksrules said:

I am in Mumbai too and we have AC on most of the night. We were of the opinion that AC dries the air so we have a humidifier running entire night in bedroom too. Are we doing wrong? Should we sell Humidifier and instead get a dehumidifier and do we get air purifiers with dehumidifiers built in?

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AC should be fine, but in winter will you make room cooler ? It will dehumidify only when temperature is bought down vs outside air. I am not 100% sure, but from what i read in mumbai winters at night, humidity does rise to high levels. So far its true but need to see peak winter. So I started with dehumidifier to do it every day x 12 months and later will need to add AC too, esp for summers.

Not sure why you would need humidifier in mumbai, maybe only in winter mornings? Have to see how low it goes. These days its around 60-70. 60-65+ is high and 40- is low.

You can get a sensor that measures 2.5 and humidity/temp and then decide how you want air to be. I am using Ikea sensor(VINDSTYRKA ) and it works well and cost is reasonable ( 4k or 5k - was 1k in sale).

Tracer_Bullet said:

AC should be fine, but in winter will you make room cooler ? It will dehumidify only when temperature is bought down vs outside air. I am not 100% sure, but from what i read in mumbai winters at night, humidity does rise to high levels. So far its true but need to see peak winter. So I started with dehumidifier to do it every day x 12 months and later will need to add AC too, esp for summers.

Not sure why you would need humidifier in mumbai, maybe only in winter mornings? Have to see how low it goes. These days its around 60-70. 60-65+ is high and 40- is low.

You can get a sensor that measures 2.5 and humidity/temp and then decide how you want air to be. I am using Ikea sensor(VINDSTYRKA ) and it works well and cost is reasonable ( 4k or 5k - was 1k in sale).

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Still confused. Are you saying humidifier is futile in Mumbai irrespective of season?

raksrules said:

Still confused. Are you saying humidifier is futile in Mumbai irrespective of season?

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1) Mumbai is very humid. In monsoon i saw 99% RH and generally i see > 70 during night.
2) Humidifier is used to increase humidity. Ideal humidity is 40-60. 60 is comfortable, a user here reported that he had issues below 60. ( he also uses dehumidifier ). What i want is to keep it around 60, esp at nights. High humidity can lead to mold and dust mite issues. Also leads to corrosion in electronics.
3) Only time humidifier would be useful is when humidity is very low ( say less than 40 relative humidity ) which i think only happens in winter during the day. Not sure on this as this is first winter in which i will monitor this via sensor. Also this might be subjective. So far i have not seen < 40. Only > 65 when dehumidifier is not on and it starts increasing at night.
4) ACs bring down humidity when indoor temp is set below outdoor temp. There is dry mode, not sure about that but from what i read, dehumidifier are most effective at bringing down humidity. It also uses much lower power, but it does increase room temp by 1 or 2 degrees. So peak summer, we need acs too.

Get a sensor, then you will know whats exactly happening in your room at different times and different seasons.

Renegade said:

So would mostly settle down for one which has a companion app

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Just note that the automatic mode in AP ( from what i read ) is generally not good. Sensors are not accurate and AP is not aggressive enough. Ideal average long term PM2.5 is < 5 ( UN recommendation i think ) and generally, auto modes increase fan speed at much higher values.

I just keep it running at speed 3 ( out of 5) in my AP most of the time, noise is low and its pretty effective. Sometimes if my room has too high PM ( windows opened /someone buring /etc), then i ramp it up to 4/5 for 30 mins or so. Even 3 would be effective but would take more time to clear out room.

My unit has some automation and app control too, i just ignore it.

Renegade said:

With the pollution levels rising, cold/cough frequency increasing and lasting for weeks instead of days, are the home air purifiers helpful at alleviating the situation? And will it make any difference if it is used only at night?

Click to expand...

I used to have severe morning allergies (a few months every year) and constantly sneezed for 30 minutes or more, which drained me physically and mentally. I don’t remember having the same experience since I got an air purifier. I keep it on all the time, and the doors are frequently open, letting air in, but it still feels helpful. It’s a simple, no-BS air purifier called Sqair, and it has no app or settings apart from speed. I still have a sneezing marathon for a short time when exposed to dust, but things have felt much better since the air purifier has reduced the dust levels around me. I purchased 2 more units for other rooms and I’m happy with it.