Best interval to change 1" pleated filters? MERV 8 ok?

[readytobecool]

Just had a new system installed, and it has a 20 x 25 x 1 filter in it. From what I've read on here so far, it seems that I don't want to go too high of a MERV rating in the 1" filters due to the higher MERV filters restricting air flow, so I was going to go with a mid-level True Blue filter which I think is a MERV 7 or 8.

(1) Does that sound good to go with a mid-level, 7 or 8 MERV pleated filter for my 1"filter, and

(2) What would the recommended interval be to change it out? They say on them that they're good for 90 days, but I imagine that by then they would likely be restricting the airflow pretty good. I was thinking maybe every 1 1/2 months would be better? Or, even every month? Would that be wasteful to change the 3 month filters every month?

[jerryd_2008]

Don't know where you are located but here in NW Arkansas, the collar months between the heating/cooling and cooling heating seasons can be months long. Not much HVAC use then. Why change the filter every month? Check it regularly. My 6 MERV 1 " pleated Lowe's specials almost never seemed really dirty even at 3 months.

Just put in new system and this one has one 5" MERV 11 filter at the furnace.

[RoBoTeq]

1" pleated filters should be replaced once....by a filter that is not doing harm to the HVAC system

[gary_g]

I use NaturalAire Standard pleated filters (MERV 8) made by Flanders. $8 for a 3 pack at HD.

I used to change them monthly, now it's every 3 months, regardless of the season.

Everyone's situation is different.

I have no issues with air flow.

Take care.

[Border411]

I use NaturalAire Standard pleated filters (MERV 8) made by Flanders. $8 for a 3 pack at HD.

I used to change them monthly, now it's every 3 months, regardless of the season.

Everyone's situation is different.

I have no issues with air flow.

Take care.

After a TON of research on this topic on this forums....that is now what I am doing. The filters from HD (NaturalAire MERV 8 "Standard") seem to be working A LOT bettetr, with much better airflow over the Filtret 1250 filters I was using. I am going to see how the first 3 months look on this filter, checking it every couple of weeks, then gauge my filter change interval from there.

[RoBoTeq]

I use NaturalAire Standard pleated filters (MERV 8) made by Flanders. $8 for a 3 pack at HD.

I used to change them monthly, now it's every 3 months, regardless of the season.

Everyone's situation is different.

I have no issues with air flow.

Take care.

Unless you have greatly oversized your return filter rack, I'd be willing to make a wager that you do have an airflow issue.

[AvantGarde]

www.dirtyfilters.com

Nice air flow and good protection for the equipment and their built like a brick you know what.

[RoBoTeq]

After a TON of research on this topic on this forums....that is now what I am doing. The filters from HD (NaturalAire MERV 8 "Standard") seem to be working A LOT bettetr, with much better airflow over the Filtret 1250 filters I was using. I am going to see how the first 3 months look on this filter, checking it every couple of weeks, then gauge my filter change interval from there.

Have you actually had your systems airflow tested? Try this; run your heat with a standard paper framed fiberglass filter (perfectly acceptable for protecting HVAC equipment) and check for the temperature difference between a spot in the return portion of your unit and a point just before the first branch duct take-off. Now do the same test with the pleated filter.

[RoBoTeq]

www.dirtyfilters.com

Nice air flow and good protection for the equipment and their built like a brick you know what.

Wow! These must be super duper pleated filters. This company even claims that their filters make your hvac system more efficient. WHAT A CROCK!

You people who buy these 1" pleated filters miss Billy Mays, don't you?

[arcticbreeze]

I agree with robo 300%. I wish they stopped making those things. In my area 90% of the homes have duct systems designed marginally with the "cheap" filters. Customer pops in a pleated from Home Depot and all of the sudden the system has problems. Unless your duct system was specifically designed for those filters you will probably have reduce air flow, capacity and efficiency. You may not notice the difference yourself but if you have a tech actually measure the external static pressure and compare it to the appropriate fan data chart the numbers will not lie. In the filter world higher efficiency means more restrictive.

[RoBoTeq]

Yepper. An HVAC air filter should be doing one thing; keeping your HVAC system clean. If you want to make the air in your home healtier, have a by-pass type HEPA filter installed and stop using all of that smelly crap that is ruining your health and eating up your HVAC system.

Anything that has an artificial scent is bad for your health and for your HVAC system. Instead of ruining your HVAC system by trying to clean up the air, try not polluting your air in the first place. 99% of the allergins in the average home are not even airbourne. Run your air system while you vacuum and change your cheapo filters regularly or have a by-pass filtration system installed.

[gary_g]

Unless you have greatly oversized your return filter rack, I'd be willing to make a wager that you do have an airflow issue.

I'll take that bet.

Temp measurements after the evap coil on my system are right on spec, after 1 month or 3 months of the same filter.

[gary_g]

..... a standard paper framed fiberglass filter (perfectly acceptable for protecting HVAC equipment)....

No way. Those cheapo blue spun fiberglass filters allow too much dirt to pass through and deposit on the evap coil.

[RoBoTeq]

I'll take that bet.

Temp measurements after the evap coil on my system are right on spec, after 1 month or 3 months of the same filter.

Since I know that you are diligent in your data collecting, I will assume that there is something about your system that is different then most or that this particular filter, one that I have not tested, is different then all of the other 1" pleated filters I have tested.

[RoBoTeq]

No way. Those cheapo blue spun fiberglass filters allow too much dirt to pass through and deposit on the evap coil.

They are all I've used on the old oil furnace with the new heat pump coil in my home for the past four years. As long as they are seated properly and not allowed to get stacked with dirt, they are the best protection for your HVAC system without causing undo harm due to restrictions.

I also like the frameless hogs hair filters, but they can be a pain to keep from collapsing.

Most of the stuff that gets into our HVAC systems get their from bypassing the air filter, not from getting through it.

[readytobecool]

Well, the discussion has been interesting to read, but unforutunately I'm not much closer to knowing what to do. It seems that even the professionals disagree about not only when to change the 1" filter, but whether to use a cheap basic filter or to use a pleated one and if a pleated one, then which of the various MERV ratings, and also whether using a 1" filter is even protecting your system or damaging your system due to restricted air flow. One would think the industry would have narrowed it down by now what the best practice was based on cost and filtering ability.

[RoBoTeq]

Well, the discussion has been interesting to read, but unforutunately I'm not much closer to knowing what to do. It seems that even the professionals disagree about not only when to change the 1" filter, but whether to use a cheap basic filter or to use a pleated one and if a pleated one, then which of the various MERV ratings, and also whether using a 1" filter is even protecting your system or damaging your system due to restricted air flow. One would think the industry would have narrowed it down by now what the best practice was based on cost and filtering ability.

Unfortunately there are no definitive standards for a filters restrictive value. The thing to keep in mind is that an air filter's primary and only intended function is to protect the HVAC equipment.

If manufacturer's of equipment provide better then standard filtration or offer it as an option, you will notice they are always oversized, such as the 2" pleated Merv 11 filters that come on ClimateMaster geothermal units, or of the less restrictive wider variety, such as the Trane Clean Effects.

[Hillside]

As someone has noted, there is no standard time to change the filter. For example, with a very mild summer here in Maryland I have had my a/c on for only two days. I know
that I should not use the "H-word" cheapo thermostat for fear of being stoned by the pros, but this thermostat does have a time function and with this I change my filters, winter and summer, every 500 hours. Since my last change in March I have only 15 hours that the furnace/ac has been running. So time run rather than calendar time is important, unless you run your unit constantly.

[dash]

Unfortunately there are no definitive standards for a filters restrictive value. The thing to keep in mind is that an air filter's primary and only intended function is to protect the HVAC equipment.

If manufacturer's of equipment provide better then standard filtration or offer it as an option, you will notice they are always oversized, such as the 2" pleated Merv 11 filters that come on ClimateMaster geothermal units, or of the less restrictive wider variety, such as the Trane Clean Effects.

Oversized by mfg.,how the make them to fit the furnace or air handler,hardly oversized. Pressure drop on them is much greater then the furnace or air handler filter.

That said,there are relatively low PD 1" merv 6 filters.

Look at the specs on cheap spun-glass filter and worse yet hogs hair,no way do they protect the equipment.Of all the things you claim,this is where you are the most incorrect,filters need to be merv 6 or more to protect the equipment.

Check the specs,there are merv 6 1" pleated filters that the PD is not that bad,likely not at home depot,but they are available.

[RoBoTeq]

Oversized by mfg.,how the make them to fit the furnace or air handler,hardly oversized. Pressure drop on them is much greater then the furnace or air handler filter.

That said,there are relatively low PD 1" merv 6 filters.

Look at the specs on cheap spun-glass filter and worse yet hogs hair,no way do they protect the equipment.Of all the things you claim,this is where you are the most incorrect,filters need to be merv 6 or more to protect the equipment.

Check the specs,there are merv 6 1" pleated filters that the PD is not that bad,likely not at home depot,but they are available.

My many years of direct experience with PM on various systems along with my in house testing of many filters in my training/testing facilities tell me that you are wrong. Do you care to offer any data or are you just here to contradict me as usual?

As for my comment about oversized filters dash, if you actually read and understood what you are reading you would have understood me to have mentioned that the ClimateMaster unit's filter is oversized.....which it is. I cannot help it if you are not informed of such things.