Old Air Purifiers With Almost No Flow

[gathermewool]

The wife and I have pretty bad allergies, so we maintain at least one air purifier on in our bedroom and another in the living room, behind the TV.

Both seem to have very little flow rate after many years in service (5-10, I believe,) which did not change after new filters that were identical to OEM were installed. With the filter removed the flow rate is what I remember it being, with a filter installed, back when we first got it. I say this, because I used to use one at my place and the other at hers to keep me cool (and for white noise) in the hot summers, and recall each doing the job reasonably well, even if not positioned directly in front of me.

The one in our bedroom has been retired due to extremely poor performance, and replaced with an expensive 5-stage HEPA purifier, which usually runs on "turbo" or "high", the two highest settings, 24/7. The airflow is high and, based on the pre-screen looking like the dryer screen, surmise that it's doing its job.

The one behind the TV is still in operation, because purifiers are expensive, but:

I want to ask if they can be refurbished or if their motors are junk and of limited lifespan (i.e., is these something I can crack open and clean/lube are are they throwaway items?) It's >5 years old, as was the one that was replaced from the bedroom. I don't have them in front of me, but they're both Holmes brand.

This is the purifier I bought for the bedroom (on-sale, for around $450, IIRC.): FILTER

 

[JamesBond]

I clean and oil the bearings/bushings on my cheap window and table fans every 6 mos. The only wear item in these little fan motors seems to be the bearings, if you keep them cleaned and lubed, they last a long time.

 

[gathermewool]

Do you use 3-in-1 or something thicker?

Has your method ever restored performance to an older, neglected fan motor?

One point to make: the blower on these is downstream of the filter, obviously, which means there really shouldn't be much buildup. Taking a peek behind the filter in each shows nothing but clean plastic, without any trace of dust, except at the point where the filter meets the housing.

The one HEPA filter (that was previously used in the BR) airflow is so low that it will be tossed anyway, so it won't bother me if it's destroyed in the process of refurb'ing.

 

[Ramblejam]

Originally Posted By: gathermewool
Do you use 3-in-1 or something thicker?


3-IN-ONE Motor Oil. This is different than the regular version that you're familiar with.

 

[gathermewool]

Originally Posted By: Ramblejam
Originally Posted By: gathermewool
Do you use 3-in-1 or something thicker?


3-IN-ONE Motor Oil. This is different than the regular version that you're familiar with.

That's exactly the stuff I have, and what I bought for my Furnace motor and blower.

 

[JamesBond]

Yes, I use the 3 in1 electric motor oil, but have recently bought a Laco zoom spout oiler from amazon and whatever oil is in there is thinner than the 3 in 1 and seems to make the fan spin faster. Other oils that I have tried seem to gum up in a few months.

Your motor is probably free of dust and hair but could probably use a cleaning and oiling none the less.

And yes this does restore performance to old fans. Table fans that would not spin without a push to the blades to get them going and would stop immediately upon turning off the switch, now work like new with regular maintenance. I first tried this on a fan that I thought was ready for the trash, and it came back to life.

 

[gathermewool]

Originally Posted By: JamesBond
Yes, I use the 3 in1 electric motor oil, but have recently bought a Laco zoom spout oiler from amazon and whatever oil is in there is thinner than the 3 in 1 and seems to make the fan spin faster. Other oils that I have tried seem to gum up in a few months.

Your motor is probably free of dust and hair but could probably use a cleaning and oiling none the less.

And yes this does restore performance to old fans. Table fans that would not spin without a push to the blades to get them going and would stop immediately upon turning off the switch, now work like new with regular maintenance. I first tried this on a fan that I thought was ready for the trash, and it came back to life.


That's very encouraging, thank you. I'll tear the retired filter apart tonight, if the little one gives me a few moments of peace.

 

[gathermewool]

I pulled apart the Holmes HAP633 and found just a small dust bunny on the outside of the motor vents ports. The rotor spun freely, but there was a little resistance, so I lubricated each end and spun it by hand to work the 3-in-1 in.

Well, After reassembling and letting it run for 10 minutes I've noticed no change at all. I may remove the filter (leaving only the pre-filter) and use it to push cool air from the kitchen into the living room. It seems to push a decent amount of air without the filter, but isn't even worth running with a filter, based on how much flow noise it makes with nothing really to show for it...

//

I was wrong about the other purifier, the HAP9412B, however. I thought I remembered cleaning it not too long ago, but with the new baby and other obligations, I think it was more like 3-4 months ago. Anyway, the pre-filter was caked in dust! I shop-vac'd that and the paper filter suction side and when I put it all back together, the flow rate was much improved.

It's still not even close to what I remember -- I used to use it to keep me cool and remember it putting out enough to do so way back when -- but it's good enough to stay in service. It's not really big enough to cover the living room, let alone the entire downstairs, so I'll be looking for a much larger unit, like the one in our bedroom, to buy when I see one on sale. I may even ask Amazon if they'll cut me a deal on a second one.

 

[sleddriver]

Since you commented on bad allergies, do you have central air conditioning and heating? Is your house "leaky"? Is there a lot of dust about?

 

[sleddriver]

Originally Posted By: gathermewool
I pulled apart the Holmes HAP633 and found just a small dust bunny on the outside of the motor vents ports. The rotor spun freely, but there was a little resistance, so I lubricated each end and spun it by hand to work the 3-in-1 in.

Well, After reassembling and letting it run for 10 minutes I've noticed no change at all.

Odds are you are dealing with a sintered bushing motor, not one with bearings. These have an oil reservoir in the form of a cotton pad. Over time & use, the pads dry out and the cotton will break down. The bushing may also "clog" not allowing the shaft to be oiled.

I know this because I resurrected an old Vornado floor fan that would not start without a flick of the finger. It also ran hot. The solution was to disassemble the motor, grind the rivets off the bushing cup, soak the bushing in something to clean it, replace the cotton, then reinstall the bushing cup and slowly fill it with oil. You need to saturate it thoroughly. I'd leave it for 30 min., then add more, leave it, then add more, etc. Before reassembling, I polished up the ends of the motor shaft.

It still works fine to this day...and doesn't overheat.

 

[JamesBond]

Originally Posted By: sleddriver

Odds are you are dealing with a sintered bushing motor, not one with bearings. These have an oil reservoir in the form of a cotton pad. Over time & use, the pads dry out and the cotton will break down. The bushing may also "clog" not allowing the shaft to be oiled.

I know this because I resurrected an old Vornado floor fan that would not start without a flick of the finger. It also ran hot. The solution was to disassemble the motor, grind the rivets off the bushing cup, soak the bushing in something to clean it, replace the cotton, then reinstall the bushing cup and slowly fill it with oil. You need to saturate it thoroughly. I'd leave it for 30 min., then add more, leave it, then add more, etc. Before reassembling, I polished up the ends of the motor shaft.

It still works fine to this day...and doesn't overheat.


Yes this is what I do. The covers to the oil pads have holes so I've never removed them, just fill the area with oil and let it sit for a few hours then wipe up any extra.

 

[gathermewool]

Originally Posted By: sleddriver
Since you commented on bad allergies, do you have central air conditioning and heating? Is your house "leaky"? Is there a lot of dust about?


We have window A/C units and central heat.

We paid $99 to have our local utility send guys out to make our condo more efficient. They did a before test, installed some door sweeps and then performed an after. I don't have the numbers in front of me, but the numbers still ended up being only barely SAT, according to them. Our windows are 5 years old, but do seal pretty well. It's the doors that are the issue.

Downstairs accumulates a moderate amount of dust, but nothing crazy. Upstairs has been great since we've been running the ridiculously expensive (for me, anyway) HEPA filter. Dust still accumulates, but we rarely have to dust now.

 

[gathermewool]

Originally Posted By: sleddriver
Originally Posted By: gathermewool
I pulled apart the Holmes HAP633 and found just a small dust bunny on the outside of the motor vents ports. The rotor spun freely, but there was a little resistance, so I lubricated each end and spun it by hand to work the 3-in-1 in.

Well, After reassembling and letting it run for 10 minutes I've noticed no change at all.

Odds are you are dealing with a sintered bushing motor, not one with bearings. These have an oil reservoir in the form of a cotton pad. Over time & use, the pads dry out and the cotton will break down. The bushing may also "clog" not allowing the shaft to be oiled.

I know this because I resurrected an old Vornado floor fan that would not start without a flick of the finger. It also ran hot. The solution was to disassemble the motor, grind the rivets off the bushing cup, soak the bushing in something to clean it, replace the cotton, then reinstall the bushing cup and slowly fill it with oil. You need to saturate it thoroughly. I'd leave it for 30 min., then add more, leave it, then add more, etc. Before reassembling, I polished up the ends of the motor shaft.

It still works fine to this day...and doesn't overheat.


I'll do this next. Our OOOOOOOOLD furnace has similar bearings in the electric motor. I pulled it apart, cleaned it and relubricated. It was doing ok, so I didn't notice any change. The blower quieted down a lot, though.

 

[sleddriver]

Originally Posted By: gathermewool
Originally Posted By: sleddriver
Since you commented on bad allergies, do you have central air conditioning and heating? Is your house "leaky"? Is there a lot of dust about?


We have window A/C units and central heat.

We paid $99 to have our local utility send guys out to make our condo more efficient. They did a before test, installed some door sweeps and then performed an after. I don't have the numbers in front of me, but the numbers still ended up being only barely SAT, according to them. Our windows are 5 years old, but do seal pretty well. It's the doors that are the issue.

Downstairs accumulates a moderate amount of dust, but nothing crazy. Upstairs has been great since we've been running the ridiculously expensive (for me, anyway) HEPA filter. Dust still accumulates, but we rarely have to dust now.

Sounds like what they did, did not do you that much good. Did they do a blower-door test? If you have the interest, I'd suggest getting some caulk, expanding foam and a flashlight. First start in the bath. Anywhere a pipe goes through a wall, foam/caulk the joint. Do the same in the kitchen. You will have a basement I'm guessing? Whenever you see a water pipe or electrical wire or conduit or sewer line go up into the wall or outdoors, foam/caulk the joint.

Your heating system needs to be sealed as well. The goal is to insure it's ONLY pulling in indoor air. NO outdoor air, no air between the studs, through the walls, etc. Only INDOOR air.

Over the years, I've taken increasing measures to seal up all air leaks in my now 33yr old house. I have A/C and the air intake box was pulling air between the stud walls and bottom plates (it is an upflow unit in a closet). During the "Winter" I crawled up on the attic and sealed up all holes and firdowns that allowed cold air to sink into wall cavities, etc. Made a LARGE difference.

Go for the big leaks first, then the smaller ones. Fine Homebuilding's website has some great articles on sealing houses in your neck o' the woods.

Every exterior door needs tight seals. You can gently pry off the interior door trim and see if you can see light from outside. Any gaps should be stuffed with fiberglass insulation OR sealed with foam specifically labeled for use with doors & windows only!

Since you have window A/C, they need to be sealed up tight as well.

This will lower the dust level, which will extend the life of your $$$$ HEPA filters, and ease your allergy-angst.

 

[gathermewool]

Originally Posted By: sleddriver
Originally Posted By: gathermewool
Originally Posted By: sleddriver
Since you commented on bad allergies, do you have central air conditioning and heating? Is your house "leaky"? Is there a lot of dust about?


We have window A/C units and central heat.

We paid $99 to have our local utility send guys out to make our condo more efficient. They did a before test, installed some door sweeps and then performed an after. I don't have the numbers in front of me, but the numbers still ended up being only barely SAT, according to them. Our windows are 5 years old, but do seal pretty well. It's the doors that are the issue.

Downstairs accumulates a moderate amount of dust, but nothing crazy. Upstairs has been great since we've been running the ridiculously expensive (for me, anyway) HEPA filter. Dust still accumulates, but we rarely have to dust now.

Sounds like what they did, did not do you that much good. Did they do a blower-door test? If you have the interest, I'd suggest getting some caulk, expanding foam and a flashlight. First start in the bath. Anywhere a pipe goes through a wall, foam/caulk the joint. Do the same in the kitchen. You will have a basement I'm guessing? Whenever you see a water pipe or electrical wire or conduit or sewer line go up into the wall or outdoors, foam/caulk the joint.

Your heating system needs to be sealed as well. The goal is to insure it's ONLY pulling in indoor air. NO outdoor air, no air between the studs, through the walls, etc. Only INDOOR air.

Over the years, I've taken increasing measures to seal up all air leaks in my now 33yr old house. I have A/C and the air intake box was pulling air between the stud walls and bottom plates (it is an upflow unit in a closet). During the "Winter" I crawled up on the attic and sealed up all holes and firdowns that allowed cold air to sink into wall cavities, etc. Made a LARGE difference.

Go for the big leaks first, then the smaller ones. Fine Homebuilding's website has some great articles on sealing houses in your neck o' the woods.

Every exterior door needs tight seals. You can gently pry off the interior door trim and see if you can see light from outside. Any gaps should be stuffed with fiberglass insulation OR sealed with foam specifically labeled for use with doors & windows only!

Since you have window A/C, they need to be sealed up tight as well.

This will lower the dust level, which will extend the life of your $$$$ HEPA filters, and ease your allergy-angst.


Material cost-wise (door seals, foam, box of LED/CFL light bulbs) I made out pretty well, but they did a very hasty job. Most of what you said was taken care of, but the foam they applied wasn't done very thoroughly. I'll follow your recommendations and track down as many leaks as possible.

I've found a few beetles that climbed through gaps in our window A/C units, and I know that there are other leaks that I should take care of (our front door is bad, really bad.)

Thanks again!

 

[sleddriver]

If your front door is that bad, that's the first place to start. If it's a the bottom, every time a gust of wind blows towards the door, it'll puff dust, dirt, etc. through the crack, into your house!

From experience, I've learned it takes patience & time to seal a house correctly. The lightbulbs and other things are quick, easy & cheap for the utility. They check that box and move on.

Good luck.

 

[gathermewool]

Originally Posted By: sleddriver
If your front door is that bad, that's the first place to start. If it's a the bottom, every time a gust of wind blows towards the door, it'll puff dust, dirt, etc. through the crack, into your house!

From experience, I've learned it takes patience & time to seal a house correctly. The lightbulbs and other things are quick, easy & cheap for the utility. They check that box and move on.

Good luck.


In the winter, while the rest of the place is warm, you can literally feel the outside cold suck the heat right out of you the closer you get to the front door. They put new sweeps on it, which helped the 'after' air flow results, but that doesn't fix the gaps all around and the cracks in the door itself.

The frame around the door looks terrible and the storm door glass is literally being held on by two tabs (out of 10.) It works well enough and our bills are pretty cheap due to the size of the condo, but our allergy issues might be the motivation needed to get going on some needed sprucing up and repairs around here.

Since the vast majority of the forced hot air ducts are run within the walls, how would you suggest I take care of that? The furnace is from the 60s, and while it seems to run just fine, could probably use an update to something more efficient. It seems that upgrading the furnace, but leaving the same inefficient ducting would be counter-productive.

Thanks for you help.