Furnace filters

Originally Posted by Lubener
Two different HVAC techs told me to run the cheap fiberglass filters and change them every month because it was more important to have good airflow which the high MERV filters restrict the airflow too much.
An HVAC tech told me exactly the same thing. Use the cheapo fiberglass filters, spray them with Pledge before installation and change every month during AC or forced air usage.
3M Filtrete Filters - Merv 11. Advice I got was if you change them regularly, the 3M Filters work great. If you don't, then the basic filters are a better choice. We change the filter monthly in heavy heating season (like January in Minnesota - hah!), and more like every 3+months in the summer when we only use the A/C occasionally. It's kept our 25+ year old Carrier system working well, so no complaints...
cheapest fiberglass one I can find at Home Depot. Change it out every 6 months, or 9 months if I forget at 6 months. It is usually pretty dusty by that point but it is still passing more air than a brand new pleated filter, at least that is what I tell myself.
Have to decide exactly what you want to accomplish. Fiberglass media stops rocks ,bottles ,kids ,cats and dogs. Most 1" filters have 1 /2" media. Pleated filters have their advantages more surface area, stiffer frame , hold the dirt better and have merv rating, electronic and eletrostatic will catch smaller particals. To get the most out of a filter furnace blower has to run 24/7 and a ceiling fan running helps stir up the air. Think of a vacuum cleaner it only picks up what it sees. Even with changing filters regularly furnace blower wheels and ac coils will get dirty after 5-10 years. My take on duct cleaning is that is the air flow was strong enough the dust wouldn't be there unless mold or critters.
I buy 6 packs of MERV 11 filters on Amazon and my thermostat reminds me via email to change them out every 2 months. Haven't had any furnace issues since we moved in.
My parents just had to replace their furnace after 21 years. I always used the 3m activated charcoal or high efficiency filters. I always used a pre filter for it.
Originally Posted by Corollaman
Just curious what furnace filter you use and when you change it. I've heard more restrictive filters are bad for the furnace. MERV ratings, fiber glass, pleated, electronic, lots to discuss here.
My furnace is 30 years old and I use 1" thick filter with a MERV rating of 7or 8. Spring and Fall use goes four months. If I start them at the beginning of summer AC (June-July-August) or winter heat (December-January-February) hen the blower gets much use, they get yanked after three months.
Originally Posted by Lubener
Two different HVAC techs told me to run the cheap fiberglass filters and change them every month because it was more important to have good airflow which the high MERV filters restrict the airflow too much. A cracked heat exchanger brought up the topic.
I used to use the higher end 3M filters. I've changed my tune, using them all up first, then going with the cheap fiberglass ones and replace them once a month.
Cheapest. Our house is not sealed well, older, windows open, dusty, rugs, why worry about air quality? If you want air quality, get an electronic electrostatic filter.air A clogged filter does not put stress on the system as the filter is in the return. The blower is large, in a leaky plenum, it's not sealed, it doesn't need air to draw to function, it only needs to blow air. A clogged filter is irrelevant to the operation of the furnace, A filter is used to help remove dust from the air.
Merv 11 but that's for a 20x25x4 filter. I only change it once a year in the spring and it looks like it could go longer based on amount of light coming through the pleats.
I use AAF EZ Flow green filters from Wally World, change them out every 3 months.
I'll echo what several have said. Part of my job is managing inventory of parts and supplies for Lennox. Right now, high MERV filters are selling at a ridiculous pace. Also, PCO (photocatalytic oxidation) and HEPA systems are in high demand. My house is set up for 1" filters. I use the MERV 8 pleated filters my company offers because I can get them at great prices, but that's all I've used for years (most stores' 1" pleated cheapies are MERV 7, which is fine). Mine are in ceiling grills so I can see when they get too loaded with dirt. I run my blower fan continuously, which not only extends the life of the motor, but also creates a constant static charge that makes the filters more efficient. I change them about every two months. If you want hospital grade air - which I find comical - a standalone air cleaner might be a better option. I also have used adhesive backed weatherstripping to create a good seal around the filters so that dust infiltration is minimal. A clean evaporator coil is what you want. There are filter sprays that are basically light spray adhesive that you can use with cheap fiberglass filters that I recommend for improving efficiency and it can be purchased at big box home stores. Much like a car air filter you really don't want to change them TOO often. My two cents...
Originally Posted by Donald
If you want high quality filtering you need to install an additional filter in a enclosure. The filters then are about 3" to 4", There are a couple of different brands of what I am suggesting. But it needs to be installed by an HVAC guy.
I think those are considered "air cleaners". We had one installed at our old house with a new furnace. I can't say if it worked or not. The house was 100 years old and the ductwork was probably half that age and we never had them cleaned.... Your basic 3/4" thick filter is only cleaning the air for the furnace so it doesn't bring in a lot of dust, pet hair, etc. It is not for providing cleaner air into the home.