The fan uses less power because it HAS less power which also makes it more quiet. Without measuring the air flow per anything (power/noise/...) it is impossible to judge how good this idea is. The provided link has a warning: "Please note this booster fan cannot be used standalone in high static pressure applications". And the filter, being H13 probably needs some 240Pa to work. I'd say for most axial compressors that is too much, especially when they operate below their max RPM which further decreases their maximum pressure, often below 100Pa. So in summary it might kinda work but probably not better than other solutions. In general it is lacking numbers.
I don't think the reasoning for why this won't work is too solid, again without numbers all of that is speculation. Not sure where you're getting 240Pa needed for a filter to work. AFAIK filters, even hepa filters, don't require any specific/minimum amount of "pressure" to work since the pressure would just be a function of airflow and surface area. Even if airflow is low, the filter would still be "working" just not at a very high rate. Different filters even at the same Merv rating can have different levels of restriction based on their design(number of pleats, overall surface area, filter material and thickness, etc). So as long as the air the fan is pulling is all coming through the filter, then all of the output air is going to be filtered.
@@justinfoster1040 Exactly. It is not airtight, but if very little air passes through the filter the project can be cosidered a fail. To effectively clean the air of a room you just NEED a lot of volume. And even if that doesn't bother you, let's remember: The Idea was using a fan with more volume instead of one with less volume and more pressure. If after assembly the volume of the high volume fan is lower than of the low volume one - what's the point? I built my unit with a high pressure fan and can only tell you that it is NEEDED for my F7/H14 combination. If you use only F7 you can probably go with any fan.
@@rainerzufall689 Yeah, but theres just no way of knowing how much air is passing through the filter, vs going around it. But it looks like the sides of the filter are softer rubber so I would imagine theres a half decent seal. This would probably be effective for a small room, not a large living room. Well yeah I guess if you have multiple filters stacked, and one of them being an incredibly restrictive H14 you're going to need a very powerful fan. But if you had a either a single less restrictive Merv 14 or maybe 16 filter, you could probably get away with a smaller/quieter fan. Typically past MERV 13 and especially past merv 16 the increase in restrictiveness vs the increase in filtering effectiveness isn't worth it unless you have a specific need for that like in a hospital. If you could get 2 cycles of air through a merv 16, for the same "cost"/difficulty of 1 cycle through a H14 you would come out probably better, not to mention the potential for system leaks with the incredibly restrictive H14. Not saying thats the actual relationship there though but you get my point. Alternatively, creating a box or something else to pull air through 2-4 MERV 16 or higher filters would allow for whatever filtering efficiency but with proportionally less restriction depending on how many filters you are able to use.
@@justinfoster1040 Well either way you need to make sure no air is going around the filter. That would simply be inefficient. When I start my fan, the low pressure inside the box pulls the filter together and into their "seat", so it seals pretty good. So almost all the air leaving the box went through the filters. I could measure the diameter and the speed of the air to calculate the volume. But let's not confuse a "powerful" fan with a "high pressure" fan. You can absolutele have a low power, high pressure fan. In my opinion the relevant thing to measure is volume of air filtered per kWh spent. That defines the concept. If you then need more absolute volume you just need to build bigger.
I made a previous post to recommend that you not use this set up because it causes the motor to slow up and than makes the motor overheat when using a HEPA filter. Also, the info regarding the booster fan states that it cannot be used in stand alone high static pressure applications; which is what this setup is with the HEPA filter. I could not find a round non-HEPA filter so I returned the products in this setup. I purchased a Levoit Core 300 air purifier listed for $99.99. The filter is smaller than the one used in this setup, but the motor is the appropriate size to pull the air through the HEPA filter without it heating up. I like this idea and that is why I tried it, but the motor sizing is not appropriate for the HEPA filter which could be a potential fire hazard.
I like that design and I already have a duct fan to spare. If you wanted too you could cover the filter with some type of mesh. Flexible plastic, metal, or porous fabric.
Awesome idea! Does it still work? Can you a do a test? With it on max setting, hold a piece of printer paper by the corner above it and measure how far above the fan the paper will stay horizontal from the air blowing up under it. Then we can get an idea of how much air it outputs compared to our purifier. And for suction, cover half the filter with a bag or paper, and then hold the paper from the top so it's hanging down parallel to the filter, and slowly move it towards the filter and measure how far before it begins to suck towards the filter, and how far before it sucks right onto the filter.
I thought that this was a great idea and I purchased these products. I found that the blower motor slows down and overheats because it is not strong enough to pull the air through the HEPA filter. I fear that the overheating will start the motor on fire; for this reason I do not recommend using this set-up with a HEPA filter. I will look for a filter that is not a HEPA filter or return the products.
Pretty girl. Going to use the same setup but with carbon filters on top and bottom. You could use a hepa on intake side and carbon on the exhaust to remove odors and very fine particles.
Great idea Emily. I would like to build something similar. Since the fan isn't really attached or sealed against the filter, do you think all of the air drawn by the fan is travelling through the filter? Or is it possible that you're getting air drawn in from around the filter / fan seal ?
With the modulator you can choose how high you turn it up. On lowest settings it’s not’s not detectable, at the highest settings it can get loud, basically as loud as any regular fan
The fan uses less power because it HAS less power which also makes it more quiet. Without measuring the air flow per anything (power/noise/...) it is impossible to judge how good this idea is. The provided link has a warning: "Please note this booster fan cannot be used standalone in high static pressure applications". And the filter, being H13 probably needs some 240Pa to work. I'd say for most axial compressors that is too much, especially when they operate below their max RPM which further decreases their maximum pressure, often below 100Pa.
So in summary it might kinda work but probably not better than other solutions. In general it is lacking numbers.
I don't think the reasoning for why this won't work is too solid, again without numbers all of that is speculation. Not sure where you're getting 240Pa needed for a filter to work. AFAIK filters, even hepa filters, don't require any specific/minimum amount of "pressure" to work since the pressure would just be a function of airflow and surface area. Even if airflow is low, the filter would still be "working" just not at a very high rate. Different filters even at the same Merv rating can have different levels of restriction based on their design(number of pleats, overall surface area, filter material and thickness, etc). So as long as the air the fan is pulling is all coming through the filter, then all of the output air is going to be filtered.
@@justinfoster1040 Exactly. It is not airtight, but if very little air passes through the filter the project can be cosidered a fail. To effectively clean the air of a room you just NEED a lot of volume. And even if that doesn't bother you, let's remember: The Idea was using a fan with more volume instead of one with less volume and more pressure. If after assembly the volume of the high volume fan is lower than of the low volume one - what's the point?
I built my unit with a high pressure fan and can only tell you that it is NEEDED for my F7/H14 combination. If you use only F7 you can probably go with any fan.
@@rainerzufall689 Yeah, but theres just no way of knowing how much air is passing through the filter, vs going around it. But it looks like the sides of the filter are softer rubber so I would imagine theres a half decent seal. This would probably be effective for a small room, not a large living room.
Well yeah I guess if you have multiple filters stacked, and one of them being an incredibly restrictive H14 you're going to need a very powerful fan. But if you had a either a single less restrictive Merv 14 or maybe 16 filter, you could probably get away with a smaller/quieter fan. Typically past MERV 13 and especially past merv 16 the increase in restrictiveness vs the increase in filtering effectiveness isn't worth it unless you have a specific need for that like in a hospital. If you could get 2 cycles of air through a merv 16, for the same "cost"/difficulty of 1 cycle through a H14 you would come out probably better, not to mention the potential for system leaks with the incredibly restrictive H14. Not saying thats the actual relationship there though but you get my point.
Alternatively, creating a box or something else to pull air through 2-4 MERV 16 or higher filters would allow for whatever filtering efficiency but with proportionally less restriction depending on how many filters you are able to use.
@@justinfoster1040 Well either way you need to make sure no air is going around the filter. That would simply be inefficient. When I start my fan, the low pressure inside the box pulls the filter together and into their "seat", so it seals pretty good. So almost all the air leaving the box went through the filters. I could measure the diameter and the speed of the air to calculate the volume. But let's not confuse a "powerful" fan with a "high pressure" fan. You can absolutele have a low power, high pressure fan. In my opinion the relevant thing to measure is volume of air filtered per kWh spent. That defines the concept. If you then need more absolute volume you just need to build bigger.
I made a previous post to recommend that you not use this set up because it causes the motor to slow up and than makes the motor overheat when using a HEPA filter. Also, the info regarding the booster fan states that it cannot be used in stand alone high static pressure applications; which is what this setup is with the HEPA filter. I could not find a round non-HEPA filter so I returned the products in this setup. I purchased a Levoit Core 300 air purifier listed for $99.99. The filter is smaller than the one used in this setup, but the motor is the appropriate size to pull the air through the HEPA filter without it heating up. I like this idea and that is why I tried it, but the motor sizing is not appropriate for the HEPA filter which could be a potential fire hazard.
I like that design and I already have a duct fan to spare. If you wanted too you could cover the filter with some type of mesh. Flexible plastic, metal, or porous fabric.
Awesome idea! Does it still work? Can you a do a test? With it on max setting, hold a piece of printer paper by the corner above it and measure how far above the fan the paper will stay horizontal from the air blowing up under it. Then we can get an idea of how much air it outputs compared to our purifier.
And for suction, cover half the filter with a bag or paper, and then hold the paper from the top so it's hanging down parallel to the filter, and slowly move it towards the filter and measure how far before it begins to suck towards the filter, and how far before it sucks right onto the filter.
I thought that this was a great idea and I purchased these products. I found that the blower motor slows down and overheats because it is not strong enough to pull the air through the HEPA filter. I fear that the overheating will start the motor on fire; for this reason I do not recommend using this set-up with a HEPA filter. I will look for a filter that is not a HEPA filter or return the products.
have you tried the Fan blowing into the filter instead of pulling it through?
Pretty girl. Going to use the same setup but with carbon filters on top and bottom. You could use a hepa on intake side and carbon on the exhaust to remove odors and very fine particles.
ive been looking for something like this! thank you for posting and providing links
Awesome
Thanks Emily I have asthma and am very sensitive
Great idea Emily. I would like to build something similar. Since the fan isn't really attached or sealed against the filter, do you think all of the air drawn by the fan is travelling through the filter? Or is it possible that you're getting air drawn in from around the filter / fan seal ?
How loud are duct fans?
With the modulator you can choose how high you turn it up. On lowest settings it’s not’s not detectable, at the highest settings it can get loud, basically as loud as any regular fan
With an ac infinity fan you can get it pretty quiet. Those metal fans are less efficient and louder.