Merv 11 pleated air filter teardown

Talk more about the gauge. Is that a standalone item that you've placed behind the filter (temporarily, permanently?) or is it part of the installed system? My HVAC system doesn't have a gauge but it seems like a nice addition.

It is a magnahelic gauge that IBM used to check filters in disk drives when they were 14" platters in a box the size of a double wide sub zero fridge. I mounted it above the filter housing looking at the vacuum in the A frame enclosure.

Very few home units will have a guage similar to that. Just a recommendation to change the filter every month or some other time limit.

Where I worked there were many air handlers that were big enough to walk in. They would have filters on a large roll that every so often would be moved down a foot ot two. There were also some filters in boxs that were about 2 feet square. Each unit would take about a dozen of the filters. All very expensive. They either had gauges similar to those or some had a clear tube that was slanted with small pipes going to a point before and after the filter.

The gauges were checked once a week and when they reached a certain point they were changed.

Years ago I saw a recommendation to just the inexpensive filters and change them once a month. I have done that for years or buy the ones that say they are good for 2 or 3 months. After about 10 years a man checked the inside coils and they were very clean. This is for a heat pump so it runs all year heating and cooling.

If you were really interested you could make a slack tube manometer from clear plastic tube and water with a drop of food coloring in it but you will have a harder time discerning a delta of 2/10th to

In the early years of our calibration equipment we had a block of plexaglass that was about 2 inches thick, a bout 2 feet long and tall. a hole about 1/4 inch in diameter was in it for most of the length and a colored fluid in part of it. The hole was on a gentle slope and calibration marks were along the length of the tube. That slant made it much easier to see small incriments of water pressure.

That would work.

I certainly wouldn't pay $75 for a gauge to do this but I had it sitting in the garage. OTOH those filters are $35 a pop so monitoring them is worth doing. You also need a pre filter of some kind if you want them to last very long in a house with pets. The filter on that louvered door catches most of the big stuff and I can just wash that one off with the hose. That gets done several times a year.

Thanks.

On Sun, 22 Aug 2021 00:38:03 -0400, snipped-for-privacy@aol.com posted for all of us to digest...

My dentist has installed some in his negative pressure rooms. He has two rooms set up with ducting, HEPA filters and had glass windows modified for the fans. They work because all the safarcus was sucked up into them. I told him he should have a smiley face in the ducting or tastes great - less filling.

On Sun, 22 Aug 2021 13:21:51 -0400, snipped-for-privacy@aol.com posted for all of us to digest...

Do you hose yourself down before or after the filter? I presume this is done prior to getting the wifes car. ;-)

Everything is after I finish working. A shower outside and then in the pool.