Furnace Filter Interval
- Thread starter RamFan
- Start date
I just look at mine, and replace when it visually looks loaded up.
This is what I do. Since I have the blower motor running continuously I end up changing the filters about every two months. With the fan set to auto the filters would last about three months.
Years ago I called the folks who make the filtrete filters, and they told me that as long as I can see light through the filter, I can still use it. So I change it when it is so gunked up that I can barely see any light coming through when I hold it up to the light.
Three months for my 4 inch MERV-12 Filters.
They look pretty good at three months but I do it anyways.
Honeywell sends me a report, I'm doing about 300 hours a month of cooling.
Roughly $20 for a new filter at Nordic Pure.
They look pretty good at three months but I do it anyways.
Honeywell sends me a report, I'm doing about 300 hours a month of cooling.
Roughly $20 for a new filter at Nordic Pure.
That's not a terrible indicator, but some the Filtrete filters that are high MERV may be too restrictive even when you can still see light through them. The larger MERV8 filter in my house will start to assume a "dome" shape as it gets loaded up. When it reaches a certain point I change the filters to avoid having them become too restrictive. That's how I arrived at the two month interval for mine.
It depends on the filter. I'm using the cheaper filters now which allow the highest airflow. I change every 2 months or so. When I was using the better filtrete filters, I would go 3-6 months depending on the season.
There are shortages locally of most filters at the Big Box Stores.
There are shortages locally of most filters at the Big Box Stores.
I ran different Merv ratings at my last house. Merv 13 kept the home cleaner and there was definitely less household dust over a long period so that is something to consider.
That is 100% true, but they are more restrictive. As long as the system was designed around a MERV13 or greater filter it should be OK, though. I am in the industry and we sell filters as high as MERV16.
I've had two different HVAC techs tell me that high efficiency filters equal extra repair business for them
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- Jul 16, 2020
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4002 - General Aire 4002 - G99 Air Filter Gage
General Aire 4002 - G99 Air Filter Gage - Since the cleanliness of all homes are not equal, GeneralAire offers an easy-to-use, easy-to-read gage. The air filter media will load, capturing airborne particulates, raising the gage indicator to the red zone, letting you know it's time to change your...
www.supplyhouse.com
It depends not only on the filter but how dusty the building is. Little things like vacuuming more often or using room air cleaners can cut down the buildup rate. Things like spending more people-hours in the building creates more (skin flake) dust.
Areas with more extreme climate changes summer/winter or leaving the blower always running will cause more running hours and clog the filter faster.
The smaller the particle size that's filtered, the faster it'll clog, and the sooner it reaches a threshold where too little air is flowing.
The best answer is check your filter and adjust the change interval accordingly.
Something many people don't consider is that eventually, and sooner the more often you have to replace (or clean) the filter, the fan will need dust cleaned out of it or else it becomes far less effective.
While the fan is out being cleaned is a good time to lube the bearings/bushings if not ball bearings. This can more than triple the life of the motor. Unfortunately most modern motor designs do not have lube ports so (at least) the rear bearing may require disassembly of the motor for access.
Areas with more extreme climate changes summer/winter or leaving the blower always running will cause more running hours and clog the filter faster.
The smaller the particle size that's filtered, the faster it'll clog, and the sooner it reaches a threshold where too little air is flowing.
The best answer is check your filter and adjust the change interval accordingly.
Something many people don't consider is that eventually, and sooner the more often you have to replace (or clean) the filter, the fan will need dust cleaned out of it or else it becomes far less effective.
While the fan is out being cleaned is a good time to lube the bearings/bushings if not ball bearings. This can more than triple the life of the motor. Unfortunately most modern motor designs do not have lube ports so (at least) the rear bearing may require disassembly of the motor for access.
No set time, when it's dirty, it gets changed.
We had a new HVAC system put in about 5 years ago. The technician said to use those cheap fiberglass filters you get at Walmart for ~$1. He said to set the filter reminder on the thermostat for 3 months and change it when it goes off. So it costs about ~$4 per year.
We used to use the heavy duty 3M filter. The tech said those were more of a gimick than anything and also hard on the blower motor with the resistance they provide. I agree with him as I had one that basically warped so bad I had to tear it to get it out.
I use the cheapest paper filter but I've had two different techs recommend fiberglass and say that buying high quality filters was the biggest source of service calls.
Nobody makes a filter for ours. I have to buy a bigger one and cut it to fit. It gets restricted enough to cause a problem about every 4 weeks.
I buy the cheapest, least filtering filters I can find and change them about once a month. This was shortly after my home was built. I bought an expensive 3M HEPA filter and within a couple weeks my air conditioner coil was freezing up. Called a technician and he said my charge was fine but my filter was plugged. I couldn't tell by looking. He recommended the cheapest filters changed once a month. So for less than a buck a filter I have had no further issues. The cat and dog hair and dander is readily visible on the filters now.
Every 3 months, per the HVAC installer. When I bought the new system, I upgraded to an electronic air cleaner, and the media inside of the cage is good for 3 months.
