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Ceiling Air Purifier

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Re: Ceiling Air Purifier

#31

Post by itsoktocry »

discreditable wrote: post #10
bombcar wrote: post #5

If you have a whole-home furnace you can often make it run the fan even if cool/heat is off - and install a high power filter and change it regularly and it’ll filter the air reasonably well. The ecobee has a “minimum fan time per hour” setting - it can also help to balance the air temperature.

I've had HVAC techs tell me not to use those thick filters unless your system is designed for it. They make the fan work harder to pull less air. This reduces how much air it can move.

>I've had HVAC techs tell me not to use those thick filters unless your system is designed for it.

Yeah, it will also shorten the lifespan of the motor since it has to work harder.

But is the cleaner air trade-off worth it? I think so.

Re: Ceiling Air Purifier

#32

Post by SOLAR_FIELDS »

havblue wrote: post #29

An ac filter is pretty gray after just a few months. Granted this will take longer to get dirty but I suspect it will look ugly before you know it.

A good reminder to change it at least. If this were a purchasable product, I envision making the filters replaceable and the frame compatible with some standard furnace filter size, so that you can just run to the store and grab new filters when you can visually see the filter needing replacement.

Contrast this with the furnace filter, which needs some other mechanism (often, a schedule) to determine when to change the filter since it's not readily visible on a daily basis.

Re: Ceiling Air Purifier

#34

Post by bombcar »

newsclues wrote: post #17
TedDoesntTalk wrote: post #8

Earlier quoted context omitted.

That’s a great idea. What kind of filter do you use?

Standard furnace filters, pick the level of filtration you desire/can afford.

I've had surprisingly good luck in my area finding brand-new furnace filters at Goodwill for quite cheap. HEPA, too. If you're making your own setup the size doesn't matter as much so that can be a good way to go.

Re: Ceiling Air Purifier

#35

Post by malfist »

itsoktocry wrote: post #31
discreditable wrote: post #10

Earlier quoted context omitted.

I've had HVAC techs tell me not to use those thick filters unless your system is designed for it. They make the fan work harder to pull less air. This reduces how much air it can move.

> I've had HVAC techs tell me not to use those thick filters unless your system is designed for it. Yeah, it will also shorten the lifespan of the motor since it has to work harder. But is the cleaner air trade-off worth it? I think so.

I've always heard this, but I don't know that that's true. The thing that dies first on an HVAC system isn't the motor, it lasts a long damn time, it's the capacitor, or contactor or some other fault not really related to the motor work load.

Plus, your "motor" isn't an engine, it's not variable speed, it only has one "hardness" that it works at. It might push less air with the thicker filter, but it's not going to ramp up and consume more wattage or anything like that.

Re: Ceiling Air Purifier

#36

Post by larrywright »

itsoktocry wrote: post #31
discreditable wrote: post #10

Earlier quoted context omitted.

I've had HVAC techs tell me not to use those thick filters unless your system is designed for it. They make the fan work harder to pull less air. This reduces how much air it can move.

> I've had HVAC techs tell me not to use those thick filters unless your system is designed for it. Yeah, it will also shorten the lifespan of the motor since it has to work harder. But is the cleaner air trade-off worth it? I think so.

It’s a trade off though, because good filters will keep dust out of the HVAC systems innards, which according to the techs I’ve talked to makes a difference in longevity.

Re: Ceiling Air Purifier

#37

Post by jefftk »

TedDoesntTalk wrote: post #8
sha256sum wrote: post #6

Great idea. What's worked for me is simply taking a 20"x20"x1" filter and sliding it into the back cover of a standard $25 Lasko box fan. Cheap, easy option for air filtration in the home.

That’s a great idea. What kind of filter do you use?

If you're doing one filter per box fan, I'd go with a MERV-14: https://www.jefftk.com/p/merv-filters-for-covid

Re: Ceiling Air Purifier

#38

Post by foobarian »

malfist wrote: post #35
itsoktocry wrote: post #31

Earlier quoted context omitted.

> I've had HVAC techs tell me not to use those thick filters unless your system is designed for it. Yeah, it will also shorten the lifespan of the motor since it has to work harder. But is the cleaner air trade-off worth it? I think so.

I've always heard this, but I don't know that that's true. The thing that dies first on an HVAC system isn't the motor, it lasts a long damn time, it's the capacitor, or contactor or some other fault not really related to the motor work load. Plus, your "motor" isn't an engine, it's not variable speed, it only has one "hardness" that it works at. It might push less air with the thicker filter, but it's not going to r…

>Plus, your "motor" isn't an engine, it's not variable speed, it only has one "hardness" that it works at.

This is incorrect - electric motors draw more current when under load. I would suggest researching this or playing with some toy electric motors run from a battery through a current meter.

Re: Ceiling Air Purifier

#39

Post by jefftk »

polskibus wrote: post #15

How do you measure PM 2.5 at home? Whats the best and cost efficient way to do it?

Details: https://www.jefftk.com/p/testing-air-purifiers

I'm using a Temtop M2000 because it was the cheapest option I found with per-minute data export: https://temtopus.com/collections/temtop-co2-monitor/products...

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