MERV Ratings and Filter Recommendations?

[nafterclifen]

I need some help in choosing a filter for my house. 4 people and a small (no shed) dog. I'm currently using the cheap Flanders fiberglass filters and have been changing them monthly. Size is 20 x 22.25 x 1 which has been impossible to find in the big box stores.

What filter brand is everyone using? And which MERV rating should I use?

Based upon some quick research, MERV 5-8 seems to be common/popular while MERV 9-12 are much better. I don't mind spending a bit extra for a quality filter but I do NOT want to risk restricting air flow.

 

[Brace1]

I use the Filtrete reds, which are MERV 11. I have heard the purple ones (higher MERV ratings) are a little too restrictive. I buy them either 6 or 12 at a time from here - http://www.fridgefilters.com/water-and-air-filters/l/brand/filtrete/merv/merv-11.html
I don't see your size though...

 

[Jackfre]

Be careful in going to a real high mere rating. It can throw your systems air circulation for a loop by introducing high resistance to air flow.

 

[zmaxmotorsports]

Be careful in going to a real high mere rating. It can throw your systems air circulation for a loop by introducing high resistance to air flow.

I have had good luck with the plain old pleated true blue filters from menards over the years,The rheem brand pleated filters at hd also seem to work good for the price.

 

[Jackfre]

I have had good luck with the plain old pleated true blue filters from menards over the years,The rheem brand pleated filters at hd also seem to work good for the price.

Do you think it worthwhile to go to the Trion Air bear type 5" pleats? I use Trion as an example, as I think they were first with this many years ago. There are many options today. I always thought this an excellent option.

 

[bobinphx]

Getting the right filter is not an easy process, but once found, your HVAC system will last longer, run more efficiently and stay cleaner.

so a couple of concepts.
1. HVAC systems are not air cleaners. Cleaner air is a byproduct of the filters which are designed to keep the evaporator coils clean and efficient.

2. Static pressure is key to keeping your HVAC system alive. All HVAC systems have a manufactures maximum static air pressure ratings. This is referred to as the Total Static pressure (TSP). The maximum TSP for most systems is between .5 and .75 inches of water column. TSP is a measurement of the supply air pressure and return vacuum pressures. Some filters can cause a significant rise in TSP, thus reducing the amount of air that flows through an HVAC system. Reduction in air flow will effect the life of an HVAC system and the efficiency of the system. You can test your TSP with a manometer or magnahelic gauge. You can find both types online.

3. MERV has nothing to do with airflow. MERV stands for Minimum Efficiency Reporting Value and is a way to express the size of the particles that will be stopped from passing through the filter, within certain airflow and pressure ranges.

So to help answer your question about merv ratings and filter recommendations, I can only tell you my experiences. Readers Digest version; 10 years ago, we had a new high seer AC system installed in our 25 year old home. We were promised all sorts of savings, no savings were realized. I started to look into the world of HVAC and found a whole lot of information. We decided to act on the information we found and by changing some flex duct to steel ducts, adding more return ducts, installing better air flowing supply resisters and using what are called Media filters, we finally got the promised energy savings. We also got a much more comfortable home with much less dust!.

so, my recommendation is a drop in 5 inch thick media filter. Drop in filters are designed to utilize the standard 1 inch ceiling or wall filter grills. They have a 1 inch thick lip that then transitions to a 5 inch thick filter. To say these filters are amazing is an understatement. Just by putting in these filters we dropped the TSP in our system from .1 to .5, which was within the manufactures maximum TSP rating. We also cut down the amount of dust in the house by about 50 percent. We previously we had to dust once per week and now we dust every two weeks. We have three dogs and two kids who are all in and out all day long!! The best part is that these filters last us 5 to 6 months!

Here is a link to the ones we use. https://www.filtersfast.com/FiltersFast-FFRAG13-Air-Filter.asp

There are many other sellers online, so please shop around.

 

[zmaxmotorsports]

The majority of homes/buildings Ive been in over the years would benefit from just having the filter checked once a month,If I had a dollar for every furnace Ive seen kicked out on the high limit from a filter that looked like it hadnt been changed in 10 years Id be living on an island someplace warm!
The same thing goes for air conditioners that had A coils froze up like an ice berg.
The biggest/baddest/most efficient/expensive furnace and Ac system in the world can be brought to its knees by something as simple as a $3.00 filter.

 

[brewchief]

The majority of homes/buildings Ive been in over the years would benefit from just having the filter checked once a month,If I had a dollar for every furnace Ive seen kicked out on the high limit from a filter that looked like it hadnt been changed in 10 years Id be living on an island someplace warm!
The same thing goes for air conditioners that had A coils froze up like an ice berg.
The biggest/baddest/most efficient/expensive furnace and Ac system in the world can be brought to its knees by something as simple as a $3.00 filter.

For years we have installed a media filter on almost every furnace we install, it's not to keep the dust out of the house as much as it is to keep the equipment clean, most of our customers get a full year out of a filter(mostly aprilaire but some lennox versions as well) and we can replace it when doing their annual service.

 

[dreasoner]

bobinphx: Did you get your static pressure numbers backward? A a filter with more surface area should drop the external static pressure, not raise it.