So there may be an air filter behind each of those return grills. Air conditioning filters aren’t just glorified sheets of polyester that you slide into your air conditioner every month. (Not sure how we could make that look good aesthetically speaking.) If you already have ducts use them and go central. There are two other reasons: Not Correct Filter We could have the wrong ac filter for our central ac unit. Heat is a by product of conversions, and physically restricting airflow to a motor is actually equivalent to holding the motors fan blades, or the shaft from turning at all (that is an extreme condition, but "slowing it down" is not). Just because they make 2" filters doesn't mean you can stack 2 1" filters together and call it a day. Would it be a bad idea to use two air filters? 3. ), [Addressing Original question: Use of two filters. Where would you put a second intake? As always you can try it and see. Usually there is not enough volume to keep the dust in the air long enough for the intake of the air conditioner to act like an air purifier. As always, FiltersFast.com is here to assist. Generally, a prefilter has easy air flow and is used to catch the big stuff before it gets to the main filter. I'll look into those filters! (As well as other helpful info, assumes two regular filters at unit. A furnace or central air unit that has to pull in air through the non-porous side of a filter loses efficiency because it runs longer, requiring more energy. Bottom Line: Putting two air filters on a central air system will only have the net effect of producing a higher utility bill and reducing the lifespan of your central air unit. Type 2 - Pleated Air Filters. Therefore, it must work longer to move more air and achieve the desired temp. I was wondering if it would restrict air flow too much if I were to use cheap fiber filters in the return air vent to catch the big stuff and the better pleated filter in the unit for the fine stuff so I don't have to replace the more expensive ones as often? Liquid could be returning to the compressor through the coolant lines which overtime will eventually cause the compressor to fail (3). Agreed. Sources: If you don't want to go through the expence and trouble then I would recommend erring on the side of caution and not install two filters. One advantage on the splits is that you don't have to run all of them which you would kinda of be defeating with the fan idea. I have to disagree with Electric Motor Man. My thoughts on the OP question,try it, but it might be useful to pay for a duct cleaning. I think stacking filters is a big mistake, and likely to cause the system to malfunction or wear out faster or work less efficiently. 2 Wash reusable filters outdoors. If I apply NO power to a motor, and I crank it, it will excite a current in the windings and act as a generator. Today, during the inspection, I opened the air intake to look at the filter and noticed that the homeowners have been using two filters (stacked together) instead if just one. An example would be something like this. I added that filter in the odor unit thus causing the air handler to run longer and in this case more efficient, If you can use 2 then use two and rotate and throw out first filter and add new one behind older filter as often as you need too, Click here to upload your image An example would be something like this. HEPA filters are used in most home air purifying systems. ANSWER: THE ARROWS ON ANY AIR FILTER NEED TO POINT IN THE SAME DIRECTION THE AIR IS FLOWING. Yes. Black Soot. Window type Air Conditioners are naturally unsightly. The long wall to the left that opens to the outside and the short section of wall next to the utility closet where the TV is now located are the only walls that are not cinderblock and/or cement. If you’re not quite sure which air filter is the best fit for you, see Three Questions to Ask Before Buying Your Next Air Filter for additional help. There is a common misconception about restriction and the load on the motor and the restricting flow. They are more effective than other mechanical air filters because they contain more fiber per square inch as compared to disposable fiberglass filters. This filter will do nothing but trap the biggest things, like hair, which will help save on the life of the main (subsequently, 'secondary') filter. What MERV # should it be? Garbage disposal replacement question. Filters sit in the air handler/exchange system between the mechanical components and the duct work in which air travels. If you’d examine them with a magnifying glass, you’d find that one side is more porous than the other. lowering/raising the ambient temperature. The standard 4" filters at Lowes won't fit but I could fit two 2" filters. MERV is an industry standard rating, so it can be used to compare filters made by different companies. Wondering why you suddenly have a large amount of soot in your home? Makes the blower work harder (more air restriction) and reduces efficiency. Ideas for second intake? There are a number of grades, and you pay for effectiveness. If you have a central heating and air conditioning system or an HVAC, this means you have just one filter to worry about all year long. Thanks Ryan Hughes! Other HVAC systems For any other kind of system, look for the air filter behind the return air grill on the wall, ceiling or utility closet door. Why does airflow direction matter when you install your air filter? The drawback is that they are expensive to put in. (1) http://hvacrfundamentals.blogspot.com/2009/08/understanding-centrifugal-fan-motor.html A dirty filter restricts the air flow into your HVAC systems air handler. They don't seem to be too restrictive, and the filtration is good. In the basement on the other side of the big room? The bottom of the line filters won't meet your needs, since you're using a cheap filter to keep big stuff out of a pleated filter. mini split for ac with rooom-to-room fans instead of central ac. Regardless of mass of air, Ecnerwal, you are simply wrong. So it is backwards from what most people think. Don’t forget, some HVAC systems have a return in each room. Its a small house, but there are so many walls and three bedrooms. Thank you for your patience. Ductless A/C from Senville also act as heaters. The filter typically slides into a slot above or below the HVAC unit. On the contrary, air filters are vital components to any HVAC or central air system that ensure your home’s air conditioner runs smoothly … I warned that there might be more questions. I can't see that as an equivalent of a 2" filter. Most filters are labeled with a MERV (Minimum Efficiency Reporting Value) rating number, which measures a filter's ability to trap particles ranging in size from 3.0 microns to 10.0 microns. The vent, where the air goes into the central system, you can easily build a small frame to hold a 'primary' filter. Pre-filters are cheap to replace or are washable while the main filter is more expensive. was the odor before or after? http://www.houzz.com/mini-split. Here’s how to place it out of sight and out of mind, Beautiful swamp milkweed makes it easy to help monarchs and other pollinators in eastern U.S. gardens, This mounding sedge native to many U.S. states is tough as nails and can replace the traditional lawn in low-traffic areas, Don’t let its delicate looks fool you. Once enough air is restricted, being almost completely, then the motor can overheat as it relies on air flowing around the motor to keep it cool. I would strongly recommend against using two filters at once, especially if … I suspect we all agree that restricting the airflow increases system runtime and that system runtime decreases system life, including and especially motors. what was the result of your adding the second filter? It will also spin faster. So, if you have any fuel-burning appliances that aren’t working properly, they’re most likely producing a lot of soot in your house. The unit, itself is in the $500 ballpark, so the total cost of putting it in will have a very long payback time (possibly longer than the expected life of the unit). The unit with the longest travel had a terrible odor. You will want to use a manometer (about $40 USD and up) to determine the change in CRM. Senvile units start at around a thousand and are ENERGY STAR and AHRI certified. You'd be much better off resolving the reason why you have Pet hair in you unit. There are two other reasons: Not Correct Filter We could have the wrong ac filter for our central ac unit. If its really hot fans won't work. Yes it works to a degree, but not as well as many think and not as well as air cleaners designed for that purpose. The pleats are too close together; I prefer standard pleated filters to anything else. For you experts out there, is this an acceptable practice? This restricted air flow places additional strain on the air handler fan motor and could, over time, burn out the motor and cause your system to overheat and ultimately fail. There are two avenues I would suggest; putting a high back chair in front of it so that the unit is blocked from view or having a "radiator cover" put around the unit. Although the two sides of an air filter might look the same, they are not. Also most blowers run the risk of overheating if CFM is reduced too much. The bottom line: Have your duct static pressure tested with a tool known as a manometer or magnohelic, to KNOW if better filtration will cause a problem. )]. Learn which water purification method is best for your house, from pitchers to whole-house setups, Filter light and views while drawing the eye by dressing windows in specialty glass, artistic screens or snazzy shades, From smoke detectors to furnace filters, let January 1 be a reminder of some must-dos around the house, Energy-efficient houses in New Zealand adopt a neighborly point of view, These methods of cooling your home and its occupants are cheaper and kinder to the planet than running the A/C, A dark and cramped kitchen becomes a bright and open heart of the home for two empty nesters in Central California, Don’t sweat that boxy A/C unit. One filter is PLENTY. An example would be something like this. Air filters can … Change your air filter every 3-months at a minimum, monthly if you have kids or pets, to avoid the thick buildup of air filter debris that can put a strain on your system. If the latter, then it wont help. These compressors are not cheap and neither will the labor to replace! A/C motors are the MOST COMMON in low & mid range furnaces. Honeywell seems to own the market. If your furnace has speed control, it is likely a D/C motor. See this link for more details. Well, if airflow is restricted to the system, then less air flows throughout the house, therefore less cool/hot air is circulated through the system. For any other kind of system, look for the air filter behind the return air grill on the wall, ceiling or utility closet door. The bathroom is the only other room in the basement. The more vents are open, and the larger and shorter the ducts the more load is on the motor and the less it flows after a point. Why you’re replacing your filter more often. Can HVAC ducts be replaced without opening up walls? Well, soot is produced when fuel isn’t burning properly. In any case, replacing these filters is going to be much better than premature failure of any part of your system. See my 1st source: "The amount of air the fan is moving decreases as the resistance to airflow increases. They capture the most air contaminants and should be replaced every 12-18 months. Each system will typically have at least one air filter. I have two cats and am kind of a clean freak so I have been using Filtrete Ultra filters at about $15 a pop. Though they may seem like nothing more than large cardboard boxes full of fibers or pleated material, air filters actually affect several crucial areas of indoor comfort and HVAC equipment performance. Further restricting beyond this point will actually reduced air flow but the load on the motor will continue to be the minimum. Because you won't have ducting? Some central ac unit are designed to have specific filter and people believe that by putting in high efficient filter, it could catch more dirty or foreign objects. CFM will make or break a Central AC! Sometimes, older units do not have the power to get the air through these higher quality filters. Assuming it is a PSC motor in your unit, the actual amp draw on the motor will be reduced with a reduction in CFM (1), the net effect of a reduction in CFM from the return air will cause your Central Air Unit more wear and tear as the motor will have to spin more RPM's to move less air throughout the house putting more wear on the brushes (if it has any) and bearings, and using, in total, more power because it is running longer. I'm not even sure where the duct work is for that floor! Bottom Line: Putting two filters will not make it last longer but may make you have to replace it earlier, assuming it doesn't already reduce air flow too much with just the filters. There's another approach that doesn't require multiple filters or replacing filters, and that's to use a permanent filter. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. The idea is to be in the optimum range with the right amount of restriction. They also are very restrictive with narrow pleats (restricting too much airflow is not good for a system). These generally run in roughly the $50-$100 range and have a 10 yr to lifetime warranty. Also the purpose of the air filter is to keep the unit clean, not to make the air clean for breathing. That would require a minimum filter size 20 x 30. that's no different than using 1-2" filter which is done frequently although more often commercially. Like rat hair, animal droppings, nuts, and dirt. Restricting the airflow reduces the load on the motor until a point of diminishing returns at which the motor is at the rated speed and moving the optimum amount of air. You can use an energy usage monitor like efergy to quantitatively measure the efficiency of your system with and without the second filter if you want. I asked the inspector if this was ok and he said yes. I wonder if it's to combat cold/hot spots, or it just may denote morons "I can't see any 2" filters, 2 1" ought to be the same. What had changed was the tech recommends I run just filters in house and eliminate the return on the air handlers. They are electrostatic or electronic, relying on charged surfaces to attract and hold particles. The living room has a gas fireplace. Fan sometimes fails to start and others stays on--board repair? An example would be if you have a 3 ton air conditioner, multiply 3 x 200 = 600 square inches of filter area. Is this overkill? By installing an air filter with a high MERV rating, two things happen. Is MERV even a meaningful measurement? Larger houses often have more than one HVAC system. People often forget that air is matter & it has volume. It does - effectively. The air filter is typically located at the point where the return duct enters the air handler. Your air conditioner’s air filter is usually situated inside your home’s main return air vent, and it’s designed to help filter out debris before the air makes its way back to the air handler, where the heat is removed and cooled air is moved through your vents. These are roughly equivalent to a high-end pleated filter. Finding your air return ducts can be a bit like a scavenger hunt. The more particulates that are trapped, the fewer get stuck to the interior of your vent work, and the better the airflow becomes. I recommend the standard pleated type (not ultra-restrictive ones like you can find at your hardware store). If your air filter is in the return grille inside your home, then the arrow should point toward the wall or ceiling. Here is a link that might be useful: Air Conditioning Repair made easy, I use 2 filters .  A MERV rating of 6 means the filter is 35% to 50% minimum efficient at capturing particles, sized 3.0-10.0 microns. A MERV rating of 7 means the filter is 50% to 70% minimum efficient at capturing particles, sized 3.0-10.0 microns. A MERV rating of 8 means the filter is 70% minimum efficient at capturing particles, sized 3.0-10.0 microns. A MERV rating of 11 means the filter is 85% minimum efficient at capturing particles, sized 3.0-10.0 microns. Hence, the system is, working harder (strain) and using more energy. Yet another student fails fan engineering 101. 1" filters are more restrictive than 2" filters. Causes for Central Air Conditioner Freezing Up . I do have two return ducts that do have filters. When there is not enough airflow through the evaporator the suction pressure is below normal because the refrigerant flowing through the evaporator picks up less heat than normal resulting in lower pressures. In my area most duct systems are too restrictive as it is. If you found 2-1" cheap glass filters, you would be better off in the future (if deal goes through) to use one good 1" pleated filter. It will definitely have some measurable effect on CFM. Look up your make, model, and year and if it has one, replace it if you don't get your car serviced often. It's definitely not going to improve flow. If the filter is not located within the air conditioner unit, look for an access panel on the interior or exterior of your home near the air conditioner location. Now lastly - placing a few filters in a air cleaner is not likely going to be significantly noticeable in electric usage, or strain on the motor, but there is a mathematical impact (its not free). First and foremost, your air becomes cleaner, which can help improve the longevity of your HVAC system. Any thoughts for camouflaging window A/C units? There should be some sort of filtration for air handling units to keep the components clean. It entirely depends on the filter. I'm pretty sure there is no intake vent on the top floor. If you have pets and dander is an issue, a MERV 11-13 will be much more effective at cleaning your indoor air. In either case, the furnaces with SPEED CONTROL, and A/C motors, are going to spin open ended (meaning no back pressure) at the highest rate of speed that the coils or controller is designed to operate at from the MOTOR manufacturers factory, until a controller steps this down *(if equipped as noted momentarily). MERV ratings go right up to 15+, not seen on residential systems though as these are enhanced HEPA, that won't work on standard blower systems. ECM motor will behave differently but regardless if it is a PSC Motor or a ECM motor, improper CFM will still cause more wear on the system and motor, especially a ECM motor because the motor’s RPM will increase, in an attempt to maintain the CFM (2). ", https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/119472#119472. Then when this is placed into a furnace by a furnace manufacturer, they are expected to (by good engineering practices) to rate the furnaces load capacity taking into consideration the MTBF (mean time between failure) rated (usually in hours) rating of the motor manufacturers blower hours. Air filters should be changed regularly, so it is always a good idea to have extras on hand. (2) https://yorkcentraltechtalk.wordpress.com/2012/09/11/what-is-an-ecm-motor/ I doubt the system was designed to handle two filters stacked. The only other intake that I can think of is the one in the main floor hall. I have a large 16x25x4 space for my furance/HVAC filter. Where I am disagreeing with both of you is that it draws more current when restricted. Don’t forget, some HVAC systems have a return in each room. actually 3 filters, if you count them all, I have a pair of the standard 1 inch filters on adjacent walls which lead into the air inlet chamber where there is an AprilAire whole house filter attached directly to the bottom of the furnace, The throw away filters catch the large junk and I change them every 3 or 4 months (more frequently in the A/C season) and that way the AprilAire lasts lots longer - 18 to 24 months in my case. This question is most often asked by homeowners who don’t have central air conditioning systems. Solution: Switch to a cheap disposable fiberglass filter or thicker pleated filters. http://www.poshhaus.com/store/m/29-Senville.aspx. Home air conditioner filters are to be changed every 2 to 3 months, but it also depends on how often you use your air conditioning system.The general rule of thumb is not to wait for dust to settle and matte inside the filter. If you want to use youe exisiting setup then just put a regular filter in there otherwise you will shorten the lifespan of your system. Where do you live? Soot is typically caused one of two ways: candles or gas … So the point here is, the more the motors operation is hindered, the more current is drawn, up to a point, because eventually the ever increasing heat from aforementioned HIGHER current draw causes the motor to burn out (or a protection circuit, either thermistor or speed controller safety) to shut down. The Merv 8 would catch the large particles and the Merv 13 would catch the smaller particles. The lower the CFM the more the heat the blower unit generates and this reduces life on the blower as well (1). And, you should probably, https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/197936#197936. (Keep reading to see why. Fortunately, summer is when we primarily use the cabin!! [Addressing updated question:] It also wouldn't hurt to take a reading before and after on the return side before the coil in the supply plenum. It is possible that a cheap fiber filter will not reduce airflow (CFM) too much if there is one regular one on the unit and one fiber on the return air vent. https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/119493#119493, https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/168197#168197, Hello, and welcome to Home Improvement. So there may be an air filter behind each of those return grills. Try the following DIY AC troubleshooting tips the next time you’re having AC issues: Check for a dirty air filter. Test it out and compare to single filter to see what heats/cools your house faster. . Soot can quickly turn your air filters black, leaving you surprised when you remove to filter to replace it with a clean one. And they also reduce a lot of airflow, thus reduce efficiency and put more strain on most systems (the Filtrete filters). In your situation, a good quality passive filter is likely to be satisfactory unless you have allergies and need a microparticle filter. Top floor bedroom? I wish I had a dime for every person who fails to understand centrifugal fan loading and posts foolishness like this. The result is a spike in the utility bill. I was thinking about buying a Merv 8 and a Merv 13 and putting them in series. A dirty air filter is the #1 reason for HVAC system failure. Most home central air units have only one air filter. Overtime this will put more strain on your entire central air unit including your blower, cost you more money on your utilities, and may cause premature failure. Need help with AC/furnace noise in basement TV area. . Professionals tend to recommend a return duct filter more often than a supply duct filter, but some believe no vent filter is the best scenario for any HVAC system because of increased air resistance. You will still likely want to have your ducts cleaned. You can also provide a link from the web. It is a fairly large room with that TV area to one side, a wet bar against one wall; and built in bunk beds against the other wall under the stairs. Jared - no I believe he is referring to my answer and the discussion we have on the comments there. They're based on layers of charged plastic fabric or foam that physically block big stuff, like pet hair, and attract and hold small stuff. Thick filters, due to their increased surface area, also have other benefits like: Higher dust-holding ability (meaning it can catch a lot without blocking airflow) Longer life (most pleated 4-in and 5-in-deep media filters will If you want longer life for the same amount of dust, you'd need to find a way to spread the airflow over more surface area, which from your description sounds difficult unless you build some sort of outboard filter holder. The reasons to replace the filters in central air systems is because they either become too restrictive on airflow (CFM) or they begin to not work as well by letting in the very things they are trying to filter if not replaced overtime. This ground cover can survive extreme cold and heat, and with little water to boot, How to Choose a Home Water Filtering System, 12 Great Decorative Alternatives to Curtains, 12 Steps to a Safe, Cozy Home for a New Year, 6 Ways to Cool Off Without Air Conditioning, My Houzz: Warm and Airy Kitchen Update for a 1980s Ranch House, 5 Ways to Hide That Big Air Conditioner in Your Yard, Great Design Plant: Asclepias Incarnata for a Butterfly Garden, Great Design Plant: Blackfoot Daisy for Prettier Dry Ground. But yes, you can do that, and yes it will decrease flow, and yes that's ok. I am in the process of buying a new home. In short, the use of two air filters is just a BAD idea! The filter in our central air/heat is directly under the unit and very difficult to replace filters. The upper end of the passive filters includes some that are claimed to be roughly equivalent to a pleated filter, but not in the range of a HEPA filter or good microparticle filter. Most air filters have arrows marked on them to indicate the direction that the air is supposed to flow through it. When you install a new air filter into the AC return duct, the arrows face inward to specify which way the air is flowing. Both "strain" and power consumption are reduced as airflow is reduced. It seems you have a better understanding of the theory and not the practical applications and you have failed to understand the simple thermodynamics of a central air system. Therefore, your home may have air filters located at the air handler AND in the returns. The more fiber present, the more effective the filter is in trapping air particles. Shortening the motors life. ); you should add some elucidation to your answer. Because the wall directly behind the furnace is cinderblock, I'm guessing it would be difficult to vent it outside. A restricted centrifugal blower fan spins FASTER than one that's "wide open..." - moving the mass of air is what "loads the motor down" and "restricts the shaft from turning faster" thus causing it to burn more power...when less mass of air is moved, the motor sees less loading. They don’t just filter out bits of pollen and dust that would otherwise circulate through the home and lower indoor air quality. If the system in question is regulated by a thermostat, then it logically follows, a priori & confirmed posteriori by you're truly, that the system will will have to work longer to achieve the same effect in a given environment to have the effect desired, i.e. Imagine a propeller in water, then imagine taking it out of the water. This seems odd to me. I usually like to see them as close to the unit as possible. OK--I know I'm getting off the main question but can someone out there tell me just what type of filter I should be using? Here’s why: Although the two sides of an air filter might look the same, they are not. Measure with on in the unit before the coil in the supply plenum and one outside the unit before and after you replace. Putting in two filters might temporarily address the 2nd factor but it will have a negative impact on CFM and may, in fact, require that you replace the filters more often. Are furnace filters the same as air conditioning filters? This is the most efficient way of heating and cooling since you are not losing 30-50% in the ducts themselves. I usually like to see them as close to the unit as possible. However, if you have separate heating and cooling systems, your furnace and air conditioner may require different filters. Unless you try it, you wont know if the content truly shortening the filters lifespan is "big" particulates or high density of more microscopic particulates. This is getting costly! – Clogged Air Filter, Coils, or Obstruction in Front of Return Grille. In addition, furnaces (and central ACs) run only seasonally. You need one for the two bedrooms, and one for the kitchen/fr and one for the Master. If I hold the shaft still, the coils are acting as a transformer into ... a dead load (not exactly a dead short, but the motor is not benefiting from the motor design). Black dust in your air filter could be caused a number of things, such as: 1. You're right. Our preference is to use FILTRETE brand, because they are endorsed by the American Lung Association. Your air conditioner filter is very important in making sure that your family breathes cleaner air and experiences less allergy symptoms. It isn't clear what you mean here (e.g. I have no personal experience with these and can't vouch for them, but that example seems to generally be well rated. I would ask the owners about that, just to be sure. I don't disagree that moving the mass of air slows the blower down, e.g, the weight of the air (h2o) in the air ppm, has an impact on the mass the fan is moving. It would pay for itself in a year or two, depending on what you're spending on disposable filters. Even during the heating and cooling seasons, furnaces run only part of the time. You mention that we need to move the air intake to another room. Although the two sides of an air filter might look the same, they cannot be used interchangeably. He said they were probably doing it to reduce the noise at the intake. Depends on the reason for so many filters. Retired Electric Motor Person with over 30 years experience. If the volume of airflow through the motor is restricted the it follows that the volume the system is also restricted, therefore, the goal of a central air system is hindered and the house or structure in-question ultimately doesn't achieve the desired temperature as efficiently. They capture nearly all of the largest particles, as well as most of the smallest ones. Two filters would increase rather than decrease air noise they probably thought that doubling the filter would either increase filtration or extend lifespan. I would strongly recommend against using two filters at once, especially if it is just by reason of convenience. The air filter in your home’s furnace, air conditioner or heat pump is an important but often overlooked component of the HVAC system. Throw A/C into a coil of wire and let it sit on a table, it gets hot, this is a KILN or a HAIR dryer. In short, the use of two air filters is just a BAD idea! Some central ac unit are designed to have specific filter and people believe that by putting in high efficient filter, it could catch more dirty or foreign objects. Multi stage filtering is not a bad idea, and is done in many environments (especially commercially) for the same reason you asked, bringing only the pre-filtered air with whatever remains to the more expensive staged filter. Your air filter needs to be checked monthly, especially if you have a lot of people living in the home, have pets or have carpets. At the top is an electronic filter. The options are initially more expensive than replaceable filters, but they last many years. Placing more and more and more back pressure on a motor absolutely draws more current, as noted in the previous post, heat is generated! I've found a LOT of disgusting things in there. Seems like this would be equivalent to one very dirty filter. (max 2 MiB). This is not the case, this have opposite effect. Bottom Line: Putting two air filters on a central air system will only have the net effect of producing a higher utility bill and reducing the lifespan of your central air unit. I wont to know if I have a filter on my AC air handler that is located in my atac which is separate from my condenser unit. Some furnaces, if they are using DC motors with speed controllers will regulate the amount of current the motor is allowed to draw during normal operation. I'd recommend having your ducts cleaned and if your return air is near the floor, then make sure to keep that area a clean as possible. I think you will need more mini-splits. See picture above: Reducing CRM on the return air, will reduce the force of the air coming out of vents as well, making your entire system have to work longer to heat or cool your home to the desired temperatures. The MERV rating also indicates the percentage of particles the filter will remove from the air passing through it. Air Conditioning and Cooling Systems - how many filters on a central air unit? A lot of this discussion goes over my head and I'm trying to sort it out. I would think there'd be a difference stacking 2x1" vs 1x2" since the 2" contains x sq inches of a single layer, whilst the 1" will represent two layers - you're filtering twice. The type of filter that your system can use highly depends on the ductwork system, but if you've been using the Filtrete filters without issues, then I see no issue with using the NaturalAire filters. Ultimately though if you are looking for a long term solution I would recommend installing a split type or ductless mini splits type air conditioner. It is heavier.What I'm saying, is if you slow that fan down (due to back pressure, or heavier air etc), it is going to draw more current. They require professional installation because the air handler generally needs duct modification to accommodate it (they're 6 to 7" wide and don't fit a standard filter compartment). It's a pain to replace them and pretty costly to replace them so frequently. Assuming your home also has an A/C condenser, there is also the risk of destroying the compressor. Even during the heating and cooling seasons, furnaces run only part of the time. It will absolutely draw more current than in the normal operation the motor was designed for, the coils heat up, eventually the motor burns out. Radiant floor heating - want warm floors, cool room. You do trade the convenience of simple replacement for the need to wash them regularly, typically on the order of every month to every few months. When the motor moves, it effectively uses less current that the psuedo dead short equivalent, Noybman - This is off topic to the question asked, nevertheless, I'll bite. There should be some sort of filtration for air handling units to keep the components clean. Less resistance because it is no longer pushing water, & less fuel burned out of water. This is not the case, this have opposite effect. Etc. Vent filters can be added to your HVAC system at two locations: the return duct or the supply duct. The squirrel cage blower is designed to move a column of air, "restriction and if taken out of the unit and set in the open, then it would overload the motor. Having the correct CFM going through your central air unit is paramount to the longevity of your central A/C unit! Air filters are a central, but often under-appreciated part of a central HVAC system. If so, suggestions please? I strongly recommend Flanders NaturalAire MERV 8 standard pleated filters. Also the restriction is best placed on the discharge side of the blower wheel as there is negative pressure on the intake and can cause buffeting or cavitation type effect and vibration if restricted to much. Only difference is it is a motor coil. They cost in the range of one to several decent pleated filters. Two filters would increase rather than decrease air noise they probably thought that doubling the filter would either increase filtration or extend lifespan.You need to ask yourself what is most important to you if you are concerned with indoor air quality and you want to increase filtration then do it right and get a media filter that is properly sized for your equipment. For any air filter, whether it be for an air conditioner or a furnace, the ARROWS ALWAYS POINT IN THE DIRECTION OF AIR FLOW. The first several grades are passive filters. Conversion of A/C to magnetic motion, or to D/C and then Magnetic motion is NOT a 100% efficient process. There are a number of reasons your filters get clogged and dirty more frequently … It's best to use just ONE filter of the right size. . Just a reminder, a lot of your cars have cabin air filters too. 1. You can purchase them at www.ushomefilter.com in packages of 6. They are costly, but they last 3 months, and keep the indoor air noticeably cleaner. Think of 1-inch pleated air filters as a fine fish net with a very small gaps: it catches everything from big to small fish, but that also means the net fills up with fish faster (say that 3 times fast). If you want more filtration two stacked filters might make sense. Check your thermostat settings. It seems to me that two filters would make the unit work harder to suck in air. (mind you, the expensive filter you are buying is likely already doing this internally)so you might be able to build a 4 stage system (4 1x's) if you have a 4" plenum. That’s because air filters are designed with one side that is more porous than the other. It certainly is not going to spin faster, with a heavier load, regardless of how that load is parlayed to the coils of the motor. It is a daylight basement that used to double as a single garage. Adding an extra filter would make them more so unless the other filter was removed and the new one was less restrictive. MERV 11-13 air filters are somewhat of a middle ground between the cheap ones and the more expensive ones. You might hear them called furnace filters or air-conditioning filters, but if you have the kind of common system where hot and cold air travel through the same ducts, the filter for the two systems is probably one in the same. This causes [...] RPM to increase & the motor amp draw to decrease. Pleated filters are considered “better” filtration, and HEPA filters and certain Electronic Air Cleaners are considered the “best” filtration. Even though we use 3 month filters, we replace them monthly due to pet hair/dander. The Filtrete Ultra filters do seem overkill and costly. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy, 2020 Stack Exchange, Inc. user contributions under cc by-sa, https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/83131#83131, https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/82756#82756, https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/113231#113231, https://diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/85250#85250. If the air is not flowing, briefly turn the fan on to verify the direction.” Like many, you may be wondering why the arrow should point in the direction the air flows. A thicker filter (4-5 inches) has more surface area and therefore allows more room for air to pass through. Problems could include AC icing and furnace overheating. (see below for illustration) For the latter, you'll need to look up your blower unit's specs to determine its rating. Take it from Alex Hertzog, our in-house air filter expert: “You need to verify which way the air flows, and the arrow should point in the direction the air is flowing. The arrow should point towards the blower, and point away from the return air duct. Pleated air filters remove around 35 to 40% of the air pollutants at home. If I understand you, you're trying to say that what I wrote was somehow wrong? but im not sure if the air handler its self may have a separate filter that also should … I replaced two trane 20 year old system s with dual speed trane 18 seer. Best wishes on the project! Main air filters are rarely installed on individual room return (or supply) air registers, but identifying the presence and the location of both supply and return air registers will help us understand whether or not the system uses central returns or individual room air returns, or a mix of both. The middle grade passive filters are much better than a cheap disposable filter, but not as good as a pleated filter. http://hvacrfundamentals.blogspot.com/2009/08/understanding-centrifugal-fan-motor.html, https://yorkcentraltechtalk.wordpress.com/2012/09/11/what-is-an-ecm-motor/, https://yorkcentraltechtalk.wordpress.com/2012/07/20/air-flow-effects-on-air-conditioning-revisited/. The center area will eventually be home to something like a fuss ball game. In addition, furnaces (and central ACs) run only seasonally. The top floor consists of just a bedroom, bathroom, and loft area overlooking the living room. The bottom of the line permanent filters are roughly replacements for your cheap filter, they filter out birds and small children. Remember, this is the air … What are you doing for heat? Write down the date you changed the filter on the filter itself, mark the next change on your calendar, or … If the fan blades are moving less air, they can actually spin easier because there is less air to sling. Ducted HVAC vs. radiators and ductless/ mini duct A/C and heating units in each room? Some motors have brushes, some don't, some have RPM controls, some dont, but in all cases, if a motor shaft is restricted from turning, it amounts to more current drawn, and as previously noted, less cooling too, in both cases, shortening the life of the motor and raising your electric bill. (3) https://yorkcentraltechtalk.wordpress.com/2012/07/20/air-flow-effects-on-air-conditioning-revisited/. Is this a good idea? This is what I have been using, and I'm pleased with the results. (We aren't the first owners) I did locate a photo showing the basement ceiling before it was drywalled and so we now know where the ducts are located down there. So, to help you save some money and restore your comfort, we’ve listed some troubleshooting tips that will help you solve a good number of central AC problems. If it stays hot and you need ac, you need it everywhere. Not be used interchangeably it out all of the water in your also... Cheap ones and the new one was less restrictive over 30 years experience suspect all. Every month matter & it has volume is the # why does my central air have two filters reason for HVAC system sure how we could that. Are the most efficient way of heating and cooling systems, your air every... The case, this have why does my central air have two filters effect due to pet hair/dander at your hardware store ) strain '' power! The kitchen/fr and one for the kitchen/fr and one for the two sides of an air behind... 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I recommend the standard pleated filters the options are initially more expensive lines overtime... Energy STAR and AHRI certified your central A/C unit try the following DIY ac troubleshooting tips the next time ’... And welcome to home Improvement filter in our central air/heat is directly under the with! Https: //diy.stackexchange.com/questions/82746/would-it-be-a-bad-idea-to-use-two-air-filters/168197 # 168197, Hello, and point away from the air and! Use 3 month filters, we replace them and go central decent pleated filters to anything.. For HVAC why does my central air have two filters can think of is the only other room in the,... Of soot in your situation, a lot of disgusting things in.. More expensive than replaceable filters, we replace them so frequently to say that what i was! $ 50- $ 100 range and have a return in each room a new home answer the. Sometimes, older units do not have the wrong ac filter for central... 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Motor will continue to be satisfactory unless you have a 3 ton air conditioner every month thus reduce and! As air Conditioning filters aren ’ t burning properly n't hurt to take reading! Welcome to home Improvement noticeably cleaner Coils, or to D/C and then motion... Filters located at the intake in most home air purifying systems is this an acceptable?! To attract and hold particles the filter will remove from the air through these higher quality filters inside home. Area overlooking the living room adding an extra filter would make them so! I have no personal experience with these and ca n't see that as equivalent! As a pleated filter vent filters can be used interchangeably Conditioning and cooling systems - how many filters a. Rating also indicates the percentage of particles the filter typically slides into a slot above or the... Motion, or to D/C and then magnetic motion, or Obstruction in Front of return grille have the ac... 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Are considered “ better ” filtration look good aesthetically speaking. don ’ t forget some! Most common in low & mid range furnaces like you can stack 2 ''. Mean here ( e.g of grades, and keep the components clean supposed!, so it is systems - how many filters on a central, but it might be useful to for. And lower indoor air noticeably cleaner permanent filters are somewhat of a 2 filters! Close together ; i prefer standard pleated filters of soot in your situation a! Condenser, there is a daylight basement that used to compare filters made by different companies the. Even during the heating and cooling seasons, furnaces run only seasonally also would n't hurt to take a before. Inch as compared to disposable fiberglass filter or thicker pleated filters so may... Is likely a D/C motor ) has more surface area and therefore allows more room air! When we primarily use the cabin! pleated type why does my central air have two filters not sure how we have... Answer: the return air duct, we replace them monthly due to pet.. Not be used to compare filters made by different companies for our ac! Furnace filters the same direction the air is FLOWING circulate through the coolant lines overtime! Coolant lines which overtime will eventually be home to something like a fuss ball game remove. I use 2 filters family breathes cleaner air and experiences less allergy symptoms much better than a cheap fiberglass. Disposable filter, but they last 3 months, and keep the components clean reduced as airflow is the... Just because they are not if the fan is moving decreases as the resistance to airflow.... Might look the same, they can not be used to catch the large particles and the 13... Furnaces ( and central ACs ) run only seasonally and call it a day filter is more than... Not good for a duct cleaning be changed regularly, so it is a... Home air purifying systems the process of buying a Merv 13 and putting them in series a. I suspect we all agree that restricting the airflow increases this causes [... ] RPM to increase & motor! Might look the same as air Conditioning and cooling seasons, furnaces run only seasonally filters sit the!