Question: I heard that the use of air filters other than what was initially installed can damage the furnace. I have a Goodman MBR air handler and the Epurair filter system. Can I use any filter that is 24 x 24 x4?

The Epurair filter is a pleated air filter and you can replace it with any other brand of pleated filter of the same dimensions. Any 24 X 24 X 4 pleated filter that will fit into the filter holder will do the job.

If you are concerned about impacting air flow in a negative way, you can check the MERV rating of the filter you are replacing and replace it with a filter that has the same rating.

It is important to point out that this applies to all filters. Brand is not important. What is important is the filter rating. For example, replacement Honeywell furnace filters can be purchased through various filter manufacturers. They are made to the same specifications as the brand name filter.

Something to think about.

Millions of products, are manufactured every day by companies that you would not recognise the names of and often in foreign Countries. The brand name company then puts their logo on the product and sells it as their own.

More Information on this Topic

- Trane furnace filters This article talks about Trane furnace filters but applies to all manufacturers of pleated furnace filters.

- Furnace filter ratings, terms and definitions.

Question: I have a Honeywell electronic furnace filter on my furnace. The power panel failed and the unit is very expensive to replace. However, I can install pleated air filters in place of the original electronic cells. The filter size is 20 X 25 X 4 inches thick. As a temporary measure, I have installed 3-1 inch thick MERV 8 air filters in parallel into the filter opening.  How does the MERV rating change when the filters are placed in parallel? Is what I have done a good solution? If not, what would you recommend that I do?

I would remove two of those 1 inch pleated air filters ASAP. Installing filters in this way has a very negative effect on air flow and reduces equipment efficiency greatly. Take a look at your air handler to see if there is a place to install a 1″ filter. Most air handlers come equipped with this filter rack.

Take a look at the pictures on this page “where is my furnace filter” if you are not sure where to look. If you can’t find a place to install a 1″ filter, you can get a 20 X25 X4 MERV 12 filter at NordicPure for a very reasonable price.

There are some common problems that home owners encounter when performing the common task of installing a new furnace filter or air

conditioner filter. Unfortunately they don’t come with directions.

After you perform this maintenance task the first time you quickly realize that it is not difficult to do. Below are links to some articles that attempt to eliminate some of the most common obstacles often encountered when installing a new air filter for the first time.

Where is my furnace filter?

Where is my furnace filter?
Before you can change or inspect your furnace filter you have to

know where it is located. Every air conditioning and heating system should have one and they can often be difficult to find. They are usually installed in the air handler but not always.

Which way do furnace filters go?

Which way do furnace filters go?
This is an important part of changing your air conditioner filter. You don’t want install your new filter the wrong way. There are usually arrows pointing in the direction of air flow. Ignore these and you can negatively impact system performance and reduce filter life. There are some other indicators to determine which way your replacement filter should go.

How do you install a furnace filter?

How do you install a furnace filter?
Sometimes filters are difficult to remove because you can’t get your fingers into the narrow opening of the air handler to remove them. Try this easy solution to make changing your furnace filter much easier.

Question: I was recently told that I could put (4) 1” inch filters together and use as a replacement for the expensive 4 inch pleated filter in my Aprilaire Spaceguard furnace filter system.

It is never a good idea to stack filters in this way.  It restricts air flow and can cause the air conditioner to ice up, among other things.

Any savings would be quickly lost due to decreased equipment efficiency and possible service calls.

Problems related to restricting air flow.

• Reduced operating efficiency
• Increased operating costs
• Evaporator coil icing up
• Reduced air flow to the home
• Longer run times
• Filters could be sucked into the fan causing damage
• Liquid refrigerant flooding back to the compressor
• Possible equipment failure

If the cost of the filter is a real concern, you could possibly install a 2 inch pleated filter into the Aprilaire Spaceguard furnace filter system.  As long as the outside dimensions are the same as the Aprilaire filter it should work.

When installing the narrower filter make certain that it is installed against the down stream side (toward the air handler) of the Aprilaire unit.  This way, air flow will help to keep the narrower pleated filter in place.  This will only work if the filter is mounted in a vertical position.  If it is mounted horizontally, this will not work and you will have to figure out a way to hold the filter in place.

Nordic Pure Anti-Allergenic Pleated Air Filters Half the price of most leading brands!

Question: I have a Water Furnace and currently use a pleated filter with a MERV 5 rating.  how high can I go before I start restricting the flow too much and damage the system?

A Merv 5 filter is really not very efficient.  If you have a properly sized duct system and you change your air filter regularly I see no reason not to use an air filter with as high as a Merv 12 rating.  as Merv ratings increase so does restriction to air flow, so you always have to be careful.  The reason I mention a properly sized duct system is because if the duct system is undersized it will restrict air flow dramatically and is a common problem in many homes.  A very efficient air filter and an undersized duct system are not a good combination.

There are a couple of signs that may indicate an undersized duct system:

-  The air conditioner coil ices up when the filter becomes dirty.  Most systems will do this if the filter becomes extremely dirty but you should not have this problem if the filter becomes only moderately dirty and you change it regularly.

- Whistling sounds coming from around the air handler access panels can be an indication of an undersized duct system.  This can also indicate poorly fitting access panels.

- If your furnace trips of on the high limit switch, this could indicate an undersized duct system.

There are other things that could cause the problems listed above but they are also signs of restricted air flow.

If you have your equipment serviced regularly ask your contractor if the duct is sized properly.  Opinions vary among contractors regarding filters with high Merv ratings.  Your other option is to try a higher Merv rating and monitor equipment operation closely.