How often do you change furnace filter ?

[HTSS_TR]

Manufacture usually recommends changing furnace filter by month, 1 month for low end filter and up to 3 months for high end filter.

I think it's better to change filter based on hours usage than time. If the furnace is running 6-10 hours a day in winter like people in the north, then 1 month is 180-300 hours usage. My furnace is not on until around Thanksgiving or after, and usually running around 30 minutes to 1 hour a day, so it run about 45-90 hours in 3 months.

There was a thin layer of dirt on the filter in spring, I just vacuumed and re-used it for another year.

 

[Quattro Pete]

I change mine every 3 months, but you're right, that is a bit dumb, now that you pointed out. Hours of usage would make more sense. Although, the way the weather is in this area, you go from using AC to using heat in a matter of days. Both AC and heater run through the same filter in my case.

 

[rshaw125]

As needed. When I check it if it's a little dusty/dirty I change it. Usually around 3 times a year.

 

[BigCahuna]

I would think it would depend on your specific house. If you have wall to wall carpet, you might get more dust in your house. If you have pets that shed, or give off dander. Or if someone in the house smokes.,,

 

[DBMaster]

Since I leave my blower fan running continuously I judge when to change by appearance - my visual "restriction gauge." I look for the larger of the two filters to reach a certain level of concavity, indicating restriction. Also, about the same time I'll start seeing the color of the smaller filter darken. I use pretty basic, $4 MERV 7 pleated filters. I have one 20x20x1 and one 12x24x1. The house only came with one return which was not enough so I added a supply plenum and a second return.

 

[SrDriver]

Once a month year around.

I use a filter rated at Merv 8 or higher. Keeps dust down in the house too.

 

[JR]

My house is heated with wood but do burn lpg furnace when out of town. it ussually is clean.

at the cabin we burn a oil furnace. we only kleen it when its plugged
remember a used dirt not plugged filter, filters more then a new one.


ken

 

[rshaw125]

Originally Posted By: DBMaster
Since I leave my blower fan running continuously I judge when to change by appearance - my visual "restriction gauge." I look for the larger of the two filters to reach a certain level of concavity, indicating restriction. Also, about the same time I'll start seeing the color of the smaller filter darken. I use pretty basic, $4 MERV 7 pleated filters. I have one 20x20x1 and one 12x24x1. The house only came with one return which was not enough so I added a supply plenum and a second return.



I would hate to have your electric bill.

 

[oldhp]

Depends on the house and the furnace too. I changed from a 16"x25"x1" to a 16"x25"x5" "thick" filter. Amazing difference in air flow, as I have a hi-flo 90% furnace. 1" filters work, but the higher the Merv rating the more you have to change them. In the spring I was changing every 20 days because filter was loading up. I have allergies which trigger my asthma so I was running a very good rated pollen filter, filters good but plugs up fast.

 

[nitehawk55]

Originally Posted By: rshaw125

Originally Posted By: DBMaster
Since I leave my blower fan running continuously I judge when to change by appearance - my visual "restriction gauge." I look for the larger of the two filters to reach a certain level of concavity, indicating restriction. Also, about the same time I'll start seeing the color of the smaller filter darken. I use pretty basic, $4 MERV 7 pleated filters. I have one 20x20x1 and one 12x24x1. The house only came with one return which was not enough so I added a supply plenum and a second return.


I would hate to have your electric bill.


New HI furnaces with DC motors do not use much .

Mine are 5" filters and I change 2 times a year and vacuum the pleats in between on the incoming side if they look like they are collecting dust . Seems to work pretty well .

 

[Rand]

I have a 95%+ efficient with 1" 16x25

I snagged 2 cases of the filtrete 1000 whatever filters.
Usually change 1-3 months. They cost me 3$ each so its not so bad.
I'm thinking about adding a second return. there is only 1 in the house and its within 5ft of 4 of the vents... bleh.

 

[HTSS_TR]

My furnace has 2 filters in size 10 x 30, the price of 20 x 30 is the same so I cut it to half instead of buying two 10 x 30. I use only 1 20 x 30 instead of 4 10 x 30 in 2 years.

I don't have air conditioning so no filter for it. The weather is mild all summer, I only turn on few table fans about 5-10 days a year.

 

[Rand]

A follow up question? Are you supposed to turn off your AC for the winter? ie pull the fuse-able link? Or do you have to run the crankcase heater all winter?

 

[OtisBlkR1]

every Three months on a assortment of 3M filters (whats on sale) and i go by date. Whenever i remove and replace the filter i write the date on the filter so i know when the three months is up.
I change the whole house water filter every 6 months unless it just gets extremely filthy (happend a couple of times).

 

[hattaresguy]

Fall and spring on all the houses I build and rentals I have. I used good filters they run around $50 each.

 

[barlowc]

3 times a year: October 1, January 1, and April 1. I generally buy my filters at Home Depot and used to use the 3M Filtrete, but last year Home Depot (at least the ones by me) switched to Honeywell-branded filters. They have a Good, Better, Best, Premium range and I use the "Best" ones which are rated FPR 9. I think "FRP" is Home Depot's own rating. Why can't they just follow a standard?

 

[Chris142]

Every 6 weeks or sooner if the air volume goes down before that.

 

[DBMaster]

Originally Posted By: rshaw125
I would hate to have your electric bill.


LOL! You wouldn't, actually. I get to shop my electricity annually. I currently pay 8.5 cents per kWh. In the winter I pay about $50/month (gas heat) and in the summer my highest bill was about $200 (I keep the house at 71 when I'm home.).

The blower motor just doesn't use that much power.

 

[OVERKILL]

Originally Posted By: oldhp
Depends on the house and the furnace too. I changed from a 16"x25"x1" to a 16"x25"x5" "thick" filter. Amazing difference in air flow, as I have a hi-flo 90% furnace. 1" filters work, but the higher the Merv rating the more you have to change them. In the spring I was changing every 20 days because filter was loading up. I have allergies which trigger my asthma so I was running a very good rated pollen filter, filters good but plugs up fast.


I was thinking of doing the same upgrade, as I currently have to change them pretty much monthly in the winter due to the pets and the house being 100 years old and subsequently a bit of a dust factory.

 

[Kestas]

Originally Posted By: Rand
A follow up question? Are you supposed to turn off your AC for the winter? ie pull the fuse-able link? Or do you have to run the crankcase heater all winter?

You don't have to to turn the a/c heater off, but it's a good idea if you want to save electricity. The only caveat is that you have to remember to turn it on before using it in the summer. I sometimes forget. On my unit, there's a box outside where you pull the connector plate and reinstall upside down for winter.