Furnace Filter Pressure Gage

[larryinnewyork]

I have a forced air furnace in the house.
I was trying to learn how long the filter could go before changing.
Most info says 3 Months. Most people look and say "yep, it's dirty"
Neither method is very accurate.

My filter is 1" thick and pleated that I buy at Home Depot.
I use 3 per year.

I started looking into - Differential Pressure Gages and installed one.
It was made by Dwyer and measures 0-2" of water. Series 2002
I'm not trying to take this filter to its max life span.
Just thought it would be nice to watch reading go higher as filter got dirty.


Furnace OFF, gage reads '0'
Furnace ON - gage reads .35
.35 would be the difference between pressure up-stream and down-stream of filter

For now, it will just be used for reference.
I'm curious what the gage will read in 3 Months.

I know if there are variables (air leaks), I won't get accurate info.

Question: Anybody use these at Home or Work ?

 

[redbone3]

I have calibrated a lot of them over the years. Many are used in "Clean" rooms to verify positive pressure inside. I never saw one used for measuring the differential pressure on a furnace filter, but I have seen them used across an orifice to measure flow (liquid and gas). I have seen differential gauges used to measure the pressure across filters used in jet refueling to insure the filter is neither saturated with dirt or blown out. Your use is absolutely valid and will give you an indication of the amount of dirt trapped by the filter.

 

[HTSS_TR]

Originally Posted By: larryinnewyork
I have a forced air furnace in the house.
I was trying to learn how long the filter could go before changing.
Most info says 3 Months. Most people look and say "yep, it's dirty"
Neither method is very accurate.

My filter is 1" thick and pleated that I buy at Home Depot.
I use 3 per year.

I need to look at my filter, it is more than a year old now. I think I probably use it more than 300-500 hours total since Aug 2014, it is used as furnace and A/C filter.

If I remember, I will take a picture of 14-15 months old filter compares with new one.

 

[JHZR2]

A manometer. Very common. It's smart to do condition based maintenance this way!