I have been using allergy filters in the home HVAC for years. Several household members and a cat are sensitive to air quality. Last year the filters I used were no longer available. I switched to a 3M Filtrete 2800 Ultrafine Filter. These are pricey. When I was at SAMs I purchased Filtrete Allergen 1200D which I used during the winter. Due to concerns of restriction if too dirty replaced every 2 months. Fast forward to today. In March a Air Scrubber was installed. The technician said run the blower motor 24 hours a day and that was what I have been doing. I thought I will just replace the filter after a month. I had a 2800 filter in a month and replaced it with 1200D. Next day cat was sneezing all day. I noticed a lot more allergies and had a hard time keeping them calmed down. This continued three days. Put old filter in and now cat is fine and I am fine. So I was told to only use the 2800 filters. Looks like current price is $30 each. Do not want to replace them too soon or too late putting stress on the HVAC system. Looking at this air filter gauge at Amazon, but has mixed reviews.
General Aire G99 Media Air Cleaner Filter Gauge
What do you think? Thanks in advance for your guidance!
Air Filter Guage for HVAC?
- Thread starter MONKEYMAN
- Start date
Well, having more information shouldn't hurt!
As a reference point, we use 4" MERV 11 filters from Menards (they're about $25 or $30) for our Carrier gas furnace and A/C.
Since it was installed in 2009, we've run the three-stage fan on low continuously. It will speed up as needed when heating on higher stages or when cooling, but it is running 24/7 (this helps equilibrate temps).
I usually change them twice a year or so, and they still look pretty good (can still easily see light through them at that time).
Several folks are allergy sufferers, and we have a dog that sheds like crazy, but this works pretty well for us. Interior surfaces don't get dusty too quickly, either.
We don't have a restriction gauge, but I have never pulled out a filter that looked too plugged up.
TmanP, was thinking of all the discussions about a filter restriction gauge for cars or trucks and how filters are changed too soon. Was thinking must be some way to monitor the filters I use at the house. Amazon has more technical gauges, but seemed to be a little too technical for my level of understanding.
I just got a flyer from my HVAC company promoting a special deal on an Air Scrubber Plus. I read what I could find on it and cannot really find any documented test results from an outside lab that say the Air Scrubber Plus does what they claim I emailed the company asking for independent test results and they have not responded.
At this point in time I am up in the air as to whether or not I think an Air Scrubber Plus is snake oil.
What size filter does your furnace take, can you use one of those MERV16 Lennox Filters , they're like 4 or 5 inches thick, they're like $100 a piece but I figure they'd probably last a lot longer than those thin 3M ones
The manual for that gauge states to calibrate it, but doesn't give any instructions.
If I were doing this, I would investigate what are the actual restriction numbers you are to be concerned with.
I use Dwyer manometers to monitor my workplace greenhouses. They give actual numbers and are simple/accurate. Here is one article I found using them for furnaces (needs more research): https://spaco.org/HomeEnergy/ChangeFurnaceFilterOnTime.htm
With some digging, you can get one delivered for under $50. https://www.google.com/search?client=firefox-b-1-d&q=manometer+for+furnace+filter
Maybe research digital manometers also: https://www.ebay.com/i/233569446711?chn=ps .....but, are they trust worthy?
Lots of YouTube videos to help you also. https://www.youtube.com/results?search_query=Checking+HVAC+filter+pressure+drop
Originally Posted by Donald
I just got a flyer from my HVAC company promoting a special deal on an Air Scrubber Plus. I read what I could find on it and cannot really find any documented test results from an outside lab that say the Air Scrubber Plus does what they claim I emailed the company asking for independent test results and they have not responded.
At this point in time I am up in the air as to whether or not I think an Air Scrubber Plus is snake oil.
Originally Posted by blufeb95
What size filter does your furnace take, can you use one of those MERV16 Lennox Filters , they're like 4 or 5 inches thick, they're like $100 a piece but I figure they'd probably last a lot longer than those thin 3M ones
You would be shocked how simple they are. A column of liquid and two vinyl air tubes - one to normal atmosphere and one in the furnace plenum. The pressure differential causes the fluid to move up/down.
You might be able to make one, but I am not positive it will work for the filter monitoring. This video shows the principle they work on:
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doitmyself, it reminds me of my childhood. We had a Coke bottle upside down in a container of water. Right before a storm the change in pressure would cause that water to rise. That was the best time to go fishing in the pond 100 yards away.
So change in pressure, fluid moves. Got it. I think long term the one you linked to would be better. It has better reviews.
Originally Posted by doitmyself
The manual for that gauge states to calibrate it, but doesn't give any instructions.
![[Linked Image from images-na.ssl-images-amazon.com]](https://images-na.ssl-images-amazon.com/images/I/61yQ5vuZ4kL._SL1100_.jpg)
Originally Posted by MONKEYMAN
Originally Posted by blufeb95
What size filter does your furnace take, can you use one of those MERV16 Lennox Filters , they're like 4 or 5 inches thick, they're like $100 a piece but I figure they'd probably last a lot longer than those thin 3M ones
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I also did not want to change my Filters to soon and waste money.
I installed this Differential Pressure Gage to monitor filter restriction (only one gage is needed, second is just to confirm).
OP needs to find the MAXIMUM Differential Pressure for 'his' Furnace (should be on label inside furnace)
Not going over the max pressure will be easier on motor.
My Furnace is a maximum of .50 inch of water column.
I now go one year per filter with the gage reading about .40" at that time.
But I also came to the conclusion I need to vacuum/dust the house more often.
Less dust/dirt in house means less dirt on Furnace Filter.
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2020/04/full-79675-44057-100_0309.jpg)
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Originally Posted by MONKEYMAN
Originally Posted by Donald
I just got a flyer from my HVAC company promoting a special deal on an Air Scrubber Plus. I read what I could find on it and cannot really find any documented test results from an outside lab that say the Air Scrubber Plus does what they claim I emailed the company asking for independent test results and they have not responded.
At this point in time I am up in the air as to whether or not I think an Air Scrubber Plus is snake oil.
Scrubbers are basically electrostatic precipitators. They use a voltage charged media to attract and trap particles from a moving air stream. This tech is used on submarines where air is 100% circulated indefinitely. Get a cheap guage and install to monitor. Filters are one of those things that get better at filtering the more they are clogged.
Originally Posted by Kawiguy454
Scrubbers are basically electrostatic precipitators. They use a voltage charged media to attract and trap particles from a moving air stream. This tech is used on submarines where air is 100% circulated indefinitely. Get a cheap guage and install to monitor. Filters are one of those things that get better at filtering the more they are clogged.