Replacement Interval for AC Filter

[Geo2008]

I was having a discussion with someone about the subject of how often to replace air filters for a home or office AC and we seemed to disagree.

So, how often do you change your filters?

What is normal?

 

[Bob_VT]

Re: Replacement Interval for AC Filter

I believe it depends on the environment that the unit is used it... ie. dust pet hair, pollen, dander....

It goes the same for the forced hot air filter in the furnace.... some may last a long time and some require monthly maintenance.

 

[tashasdaddy]

Re: Replacement Interval for AC Filter

here the HVAC people say once a month, when you check your smoke alarms.

 

[Turin]

Re: Replacement Interval for AC Filter

We don't have an airco but only a air cleaner it has to be replaced once a year for non smokers.
but in an airco where the filter gets humid I think it should be replaced more often.

The car airco is advised to be replaced once a year at least in Holland when you live some where were the air isnt as humid it has to last way longer.

 

[Pierutrus]

Re: Replacement Interval for AC Filter

Once a month in the desert SW because of the dust.

 

[642mx]

Re: Replacement Interval for AC Filter

My neighbor works for his family owned HVAC company. He always tells me to change them once a month. He even brings me a stack of freebies every few months. I still have trouble making myself change them every month because they don't look dirty at all, but since they are free, I do it anyways.

 

[achris]

Re: Replacement Interval for AC Filter

I have split system refrigerated AC systems (3 in total) and the recommended cleaning of the filters is 6 monthly. No time specified for replacement....

Chris...........

 

[arboldt]

Re: Replacement Interval for AC Filter

For clarificaton, we have a central air conditioning system using the furnace fan and ducting to distribute the cooled and dehumidified air throughout the house. This is the most typical arrangement.

Second, we use an inexpensive pleated furnace filter, *not* the fiberglass ones that are really cheap. The suggestion on these filters is to replace every 3 months.

Third, we usually have the furnace fan running for air circulation, even if there is no heating or cooling function. My wife and I prefer fresh air, so we tend to have our windows open as much as the weather permits during Michigan's 3 1/2 weeks of summer.

We've decided that with these factors, we should replace the filters monthly. That said, it's usually about every other month that we actually think about it and do it. When we do, the filter has a goodly layer of dust on it, seeming to tell us we really should do it more often. Well, we'll try to do better...

 

[TilliamWe]

Re: Replacement Interval for AC Filter

3 months for the pleated 3M filters that I buy. That us what they recommend on the package, and after three months, they look dirty enough to change.

 

[jsfinn]

Re: Replacement Interval for AC Filter

My digital thermostat keeps a timer of how long the fan has been running and tells me when it's time to replace the filter by flashing "FILT". I really have no idea how often it is - probably because it depends how hard the AC or furnace has been working. It seems like it's probably every 3 months or so though. It's defiantly dirty when I replace it.

 

[thefairlaneman]

Re: Replacement Interval for AC Filter

We use the 3m filters also. With one 20x25 filter it seems to be fairly dirty after 3 months. We have 3 long hair cats and a molting( sheads hair like a friggin sheep) akita that is so hot natured she stays in during warm weather.

 

[Navy Jr.]

Re: Replacement Interval for AC Filter

We stopped using the 3M pleated filters per our HVAC guy's suggested. Just use cheapy fiberglass ones. We get better airflow with the cheaper ones, but must change them out more often. Once a month does it, especially in the winter with the furnace going. During those "taint" months (taint summer, taint winter), I can sometimes skip a month before changing.

 

[rwise]

Re: Replacement Interval for AC Filter

I check mine monthly, if its dirty I change it, sometimes thats monthly, sometimes 6 months or more, lots of variables. In the spring or fall I may not run it (heat or cool) at all.

 

[SS MAYFLOAT]

Re: Replacement Interval for AC Filter

A lot depends on the application. The stores I service is once a month, but could be every 3 weeks. Several of the units, I use the pleated ones. They do last a couple of months longer. I get the 250' X 4' rolls and use filter cages. Cost per filter is about 40 cents.

I change the one in my house once a month using a filter cage.

Side note: When changing your filter, try to look in with the unit off to see how dirty the blower fins/vanes are. If they have a coating of dirt, (I've seen many wher you couldn't tell the fins were cupped) this will decrease your efficiency just as bad as a dirty filter. Some units make the blower assembly easy to remove for cleaning.

 

[cmchesse]

Re: Replacement Interval for AC Filter

Monthly, and they are dirty.

We have 2 dogs, 1 child, and no carpet in the house.