Furnace Filters on Steroids
Commercial/Industrial HVAC filters, aka Bag Filters, are widely
available, and are no more expensive to purchase than a 20x20x4" filter (BTW Honeywell makes 4" filters to fit standard return air grilles). These filters come in 4 standard frame sizes, 12x24, 20x20, 20x24, and 24x24. They need ALOT of room behind the filter face as the media is 10 to 37 inches deep. The filter media is 0.15 to 0.25 inches thick. Look at your pleated filter, how thick is the material in the pleats?? Thin!! Much thinner than this. Filter media is then 10 to 120 square feet in size!!! a typical residential pleated furnace filter 20x24 in size has about 6 sq ft of filter in it. They come in a variety of filter ratings from a number of different manufacturers. I have seen Purolator on several web sites. Merv ratings climb from 7 to 15. MERV15 on the Purolator models as is the case with all fitlers with this rating will capture 95% of the 1 micron and larger particles in the air, and the Purolator Defiant and Serva-Pak models will capture 80% of the 0.3 micron particles. This is almost HEPA ratings (99.97% of 0.3micron particles and up), but at a MUCH lower costs. A HEPA filter sized to treat your whole HVAC will cost you roughly $2800 to purchase and install. The filter costs about $300 when you replace it. You need the assistance of an HVAC pro to make an adapter for this in your return air plenum, and to select a model that will not place undue burden on your HVAC fan. This last point is very important as HVAC fans are not really designed to pull air thru a filter any more dense than MERV 11, and most of them work MUCH better if they have a MERV 7 or less filter in them. This is an important point, as the filter fitted by the manufacturer is there SOLELY to protect the EQUIPMENT, not to protect YOU! You can find models of the 95% filter bag that have initial pressure drops roughly the same as a Filtrete UltraAllergan. Unlike the Filtrete which may need to be changed every 2-3months, this filter will not need to be changed any more often than once or twice a year!! $40 once or twice a year vs $19 or so at least 4 perhaps 6 times a year AND you capture ENORMOUSLY more dirt, dust, pollen, mold. Your house stays MUCH cleaner. HEPA will do a better job at filtering, but it costs way more to acquire and install and the annual filter replacement is MUCH more expensive too. |
Furnace Filters on Steroids
powder coat pocke filters are the same sort of filter, they are cheaper
about 32$ for the 20x20 filter. Hepa filters put a huge strain on a blower as the pores are so small, never do this one without an experts advice on capacity. Empressess #124457 The best Games a href=http://www.gamestotal.com/Multiplayer Online Games/a a href=http://www.gamestotal.com/Strategy Games/abra href=http://uc.gamestotal.com/Unification Wars/a - a href=http://uc.gamestotal.com/Massive Multiplayer Online Games/abra href=http://gc.gamestotal.com/Galactic Conquest/a - a href=http://gc.gamestotal.com/Strategy Games/abra href=http://www.stephenyong.com/runescape.htmRunescape/abra href=http://www.stephenyong.com/kingsofchaos.htmKings of chaos/abr Robert Gammon wrote: Commercial/Industrial HVAC filters, aka Bag Filters, are widely available, and are no more expensive to purchase than a 20x20x4" filter (BTW Honeywell makes 4" filters to fit standard return air grilles). These filters come in 4 standard frame sizes, 12x24, 20x20, 20x24, and 24x24. They need ALOT of room behind the filter face as the media is 10 to 37 inches deep. The filter media is 0.15 to 0.25 inches thick. Look at your pleated filter, how thick is the material in the pleats?? Thin!! Much thinner than this. Filter media is then 10 to 120 square feet in size!!! a typical residential pleated furnace filter 20x24 in size has about 6 sq ft of filter in it. They come in a variety of filter ratings from a number of different manufacturers. I have seen Purolator on several web sites. Merv ratings climb from 7 to 15. MERV15 on the Purolator models as is the case with all fitlers with this rating will capture 95% of the 1 micron and larger particles in the air, and the Purolator Defiant and Serva-Pak models will capture 80% of the 0.3 micron particles. This is almost HEPA ratings (99.97% of 0.3micron particles and up), but at a MUCH lower costs. A HEPA filter sized to treat your whole HVAC will cost you roughly $2800 to purchase and install. The filter costs about $300 when you replace it. You need the assistance of an HVAC pro to make an adapter for this in your return air plenum, and to select a model that will not place undue burden on your HVAC fan. This last point is very important as HVAC fans are not really designed to pull air thru a filter any more dense than MERV 11, and most of them work MUCH better if they have a MERV 7 or less filter in them. This is an important point, as the filter fitted by the manufacturer is there SOLELY to protect the EQUIPMENT, not to protect YOU! You can find models of the 95% filter bag that have initial pressure drops roughly the same as a Filtrete UltraAllergan. Unlike the Filtrete which may need to be changed every 2-3months, this filter will not need to be changed any more often than once or twice a year!! $40 once or twice a year vs $19 or so at least 4 perhaps 6 times a year AND you capture ENORMOUSLY more dirt, dust, pollen, mold. Your house stays MUCH cleaner. HEPA will do a better job at filtering, but it costs way more to acquire and install and the annual filter replacement is MUCH more expensive too. |
Furnace Filters on Steroids
powder coat pocket filters are the same sort of filter, they are
cheaper about 32$ for the 20x20 filter. Hepa filters put a huge strain on a blower as the pores are so small, never do this one without an experts advice on capacity. Empressess #124457 The best Games a href=http://www.gamestotal.com/Multiplayer Online Games/a a href=http://www.gamestotal.com/Strategy Games/abra href=http://uc.gamestotal.com/Unification Wars/a - a href=http://uc.gamestotal.com/Massive Multiplayer Online Games/abra href=http://gc.gamestotal.com/Galactic Conquest/a - a href=http://gc.gamestotal.com/Strategy Games/abra href=http://www.stephenyong.com/runescape.htmRunescape/abra href=http://www.stephenyong.com/kingsofchaos.htmKings of chaos/abr Robert Gammon wrote: Commercial/Industrial HVAC filters, aka Bag Filters, are widely available, and are no more expensive to purchase than a 20x20x4" filter (BTW Honeywell makes 4" filters to fit standard return air grilles). These filters come in 4 standard frame sizes, 12x24, 20x20, 20x24, and 24x24. They need ALOT of room behind the filter face as the media is 10 to 37 inches deep. The filter media is 0.15 to 0.25 inches thick. Look at your pleated filter, how thick is the material in the pleats?? Thin!! Much thinner than this. Filter media is then 10 to 120 square feet in size!!! a typical residential pleated furnace filter 20x24 in size has about 6 sq ft of filter in it. They come in a variety of filter ratings from a number of different manufacturers. I have seen Purolator on several web sites. Merv ratings climb from 7 to 15. MERV15 on the Purolator models as is the case with all fitlers with this rating will capture 95% of the 1 micron and larger particles in the air, and the Purolator Defiant and Serva-Pak models will capture 80% of the 0.3 micron particles. This is almost HEPA ratings (99.97% of 0.3micron particles and up), but at a MUCH lower costs. A HEPA filter sized to treat your whole HVAC will cost you roughly $2800 to purchase and install. The filter costs about $300 when you replace it. You need the assistance of an HVAC pro to make an adapter for this in your return air plenum, and to select a model that will not place undue burden on your HVAC fan. This last point is very important as HVAC fans are not really designed to pull air thru a filter any more dense than MERV 11, and most of them work MUCH better if they have a MERV 7 or less filter in them. This is an important point, as the filter fitted by the manufacturer is there SOLELY to protect the EQUIPMENT, not to protect YOU! You can find models of the 95% filter bag that have initial pressure drops roughly the same as a Filtrete UltraAllergan. Unlike the Filtrete which may need to be changed every 2-3months, this filter will not need to be changed any more often than once or twice a year!! $40 once or twice a year vs $19 or so at least 4 perhaps 6 times a year AND you capture ENORMOUSLY more dirt, dust, pollen, mold. Your house stays MUCH cleaner. HEPA will do a better job at filtering, but it costs way more to acquire and install and the annual filter replacement is MUCH more expensive too. |
Furnace Filters on Steroids
|
Furnace Filters on Steroids
Hepa filters put a huge strain on a blower as the pores are so small, never do this one without an experts advice on capacity. If the filter is, say, 3" thick and had many, many pleats then the extra area can compensate for the extra resistance of the HEPA filter medium. To me, that's the way to go. Rather than a high maintenance electrostatic filter which, typically, requires 6" of space in the direction of flow, get a pleated HEPA filter that fits in the same space. |
Furnace Filters on Steroids
John Gilmer wrote:
Hepa filters put a huge strain on a blower as the pores are so small, never do this one without an experts advice on capacity. If the filter is, say, 3" thick and had many, many pleats then the extra area can compensate for the extra resistance of the HEPA filter medium. To me, that's the way to go. Rather than a high maintenance electrostatic filter which, typically, requires 6" of space in the direction of flow, get a pleated HEPA filter that fits in the same space. The issue with HEPA filters that the poster complained about is that in order to get the 99.97% entrapment of 0.3 micron particles and larger takes large amount of fan power. Furnace fans cannot do this by themselves. To move 1500 CFM (typical flow number for 4 ton AC units) through a typical HEPA filter requires almost 1HP of fan power. Air handler fans are woefully inadequate to this task as a typical air handler fan only has a tiny budget left for filter resistance.i.e. MERV7 OVERLOADS THE FAN!!! www.pureairsystems.com sells whole house HEPA filters that do not load the air handler fan as they have an internal fan that blows at the same CFM rating of the air handler . The only advantage that a 4" or 6"pleated filter has over a 1"or 2" pleated filter is a longer lifetime before they start to really bog down the air handler fan. One of these days people will start to realize that the furnace filter is there to protect the equipment, not the occupants. When you want to protect the occupants, the HP rating of the air handler fan must increase to compensate, OR we add a fan on the other side of the filter (as the pureairsystems folks have done) to PUSH air thru the filter, reducing the load on the air handler. Some manufacturers of heat pumps are starting to recognize the issue and now offer motor upgrades on some models that doubles the HP rating and gives the fan the power needed for MERV 11 and MERV 12 filters to be used. |
Furnace Filters on Steroids
Hepa filters put a huge strain on a blower as the pores are so small, never do this one without an experts advice on capacity. If the filter is, say, 3" thick and had many, many pleats then the extra area can compensate for the extra resistance of the HEPA filter medium. To me, that's the way to go. Rather than a high maintenance electrostatic filter which, typically, requires 6" of space in the direction of flow, get a pleated HEPA filter that fits in the same space. The issue with HEPA filters that the poster complained about is that in order to get the 99.97% entrapment of 0.3 micron particles and larger takes large amount of fan power. Furnace fans cannot do this by themselves. To move 1500 CFM (typical flow number for 4 ton AC units) through a typical HEPA filter requires almost 1HP of fan power. Air handler fans are woefully inadequate to this task as a typical air handler fan only has a tiny budget left for filter resistance.i.e. MERV7 OVERLOADS THE FAN!!! Shouldn't you be able counteract this by increasing the area of the filter? |
Furnace Filters on Steroids
Robert Gammon wrote:
The HEPA filter I was discussing puts a ZERO pressure drop on your HVAC system as the one I described has its OWN 1HP ECM2 fan inside... A hideous waste of energy. Use a 2 watt Envirosept filter instead. Nick |
Furnace Filters on Steroids
Robert Gammon writes:
You need the assistance of an HVAC pro ... You need help with your amathophobia. |
Furnace Filters on Steroids
Goedjn wrote:
Hepa filters put a huge strain on a blower as the pores are so small, never do this one without an experts advice on capacity. If the filter is, say, 3" thick and had many, many pleats then the extra area can compensate for the extra resistance of the HEPA filter medium. To me, that's the way to go. Rather than a high maintenance electrostatic filter which, typically, requires 6" of space in the direction of flow, get a pleated HEPA filter that fits in the same space. The issue with HEPA filters that the poster complained about is that in order to get the 99.97% entrapment of 0.3 micron particles and larger takes large amount of fan power. Furnace fans cannot do this by themselves. To move 1500 CFM (typical flow number for 4 ton AC units) through a typical HEPA filter requires almost 1HP of fan power. Air handler fans are woefully inadequate to this task as a typical air handler fan only has a tiny budget left for filter resistance.i.e. MERV7 OVERLOADS THE FAN!!! Shouldn't you be able counteract this by increasing the area of the filter? To some degree, yes. That is why pleated filters get so much attention, as they increase the surface area of the filter dramatically. Have you noticed that the 1" UltraAllergen filters from 3M have DRAMATICALLY increased the number of pleats? You can increase the size of the filter say by going from 20x20 to 20x25, more filter area. Change filter media to get higher levels of filtration (MERV goes up), or change nothing and the load on the air handler fan drops. You can increase the number of pleats in the filter, again more filter area. Change filter media to get higher levels of filtration (MERV increases), or do nothing and the load on the fan drops. You can increase the total depth of the pleats, going from 1"to 4",again lots more filter area. Change filter media to get higher levels of filtration (MERV increases), or do nothing and load on the fan drops. With each of these steps, we increase the total filter area. If the media stays constant, say MERV7, then the total dust holding capacity of the filter increases, we don't have to change it as often. But if the filter media changes, and we get a higher MERV value, the life of the filter drops, as it traps more dust faster. To get HEPA level filtration at the flow rates needed to handle your WHOLE house, i.e. 1200CFM or 2000CFM, the depth of the filter increases to 12 inches or more, filter size increases to 24x24 or more, filter media area increases to 185sq ft or more, and the type of media changes. In most big HEPA filters, the air flows thru 12 inches of filter media. In our household MERV 7 pleated media, the filter depth for airflow is under 0.1 inch (thickness of the material in the pleat). To push air thru 120 times thicker media, thru media that has higher density, requires lots of fan power. Goto www.airguard.com and look at the cut sheets (drawings) of the HEPA filters they make. This style is quite common for the 600CFM and larger HEPA filters. Hospitals and laboratories use these by the truck load. No, they don't cost $20, its more like $220 and up. |
Furnace Filters on Steroids
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Furnace Filters on Steroids
Richard J Kinch wrote:
Robert Gammon writes: You need the assistance of an HVAC pro ... You need help with your amathophobia. Phobic. Hah My BODY tells me when it is time to change the furnace filter. It not fear,its chest congestion I am not aware of how long it has been since I changed the furnace filter, until I start having fluid build in my lungs, I have a persistent lump of mucus in my throat that will not clear. I cough from time to time, and I may sneeze a bit. When these symptoms become recognizable, I go look at the date on the furnace filter and say "WOW, has it been really THAT long?? Look at that thick layer of dust." This is usually 2-3 months with most pleated filters, but seasonal pollens and molds can accelerate the filter change cycle. |
Furnace Filters on Steroids
Shouldn't you be able counteract this by increasing the area of the filter? To some degree, yes. That is why pleated filters get so much attention, as they increase the surface area of the filter dramatically. Have you noticed that the 1" UltraAllergen filters from 3M have DRAMATICALLY increased the number of pleats? You can increase the size of the filter say by going from 20x20 to 20x25, more filter area. Change filter media to get higher levels of filtration (MERV goes up), or change nothing and the load on the air handler fan drops. You can increase the number of pleats in the filter, again more filter area. Change filter media to get higher levels of filtration (MERV increases), or do nothing and the load on the fan drops. You can increase the total depth of the pleats, going from 1"to 4",again lots more filter area. Change filter media to get higher levels of filtration (MERV increases), or do nothing and load on the fan drops. With each of these steps, we increase the total filter area. If the media stays constant, say MERV7, then the total dust holding capacity of the filter increases, we don't have to change it as often. But if the filter media changes, and we get a higher MERV value, the life of the filter drops, as it traps more dust faster. To get HEPA level filtration at the flow rates needed to handle your WHOLE house, i.e. 1200CFM or 2000CFM, the depth of the filter increases to 12 inches or more, filter size increases to 24x24 or more, filter media area increases to 185sq ft or more, and the type of media changes. In most big HEPA filters, the air flows thru 12 inches of filter media. Frankly, that looks like a "reasonable" installation: a 2'x2'x1' filter box with, maybe, a cheap "pre-filter" before it to pick up the big stuff. No electrical power needed. With a 12" depth very little air would bypass the filter. This system would greatly out perform these electronic filters and the maintenance requirement would be "in the noise" to the point where it's reasonable to let the HVAC guy do it as part of his yearly checkup. In our household MERV 7 pleated media, the filter depth for airflow is under 0.1 inch (thickness of the material in the pleat). To push air thru 120 times thicker media, thru media that has higher density, requires lots of fan power. Your point is well understood and I appreciate your hard numbers. ASSuming you can get replacement filters it seems to me that for a new installation where you can spare the space for the filter cell (essentially double the air path length of a electrostatic filter) you will have "as good as you can get" air filtering. As if someone doesn't need "good as you can get" he can have DAMN GOOD with a 3 or 6" thick filter. Still to be consider is whether it's useful to get some odor control with ozone followed by charcoal. Goto www.airguard.com and look at the cut sheets (drawings) of the HEPA filters they make. This style is quite common for the 600CFM and larger HEPA filters. Hospitals and laboratories use these by the truck load. No, they don't cost $20, its more like $220 and up. |
Furnace Filters on Steroids
Robert Gammon wrote:
My BODY tells me when it is time to change the furnace filter. It not fear,its chest congestion I am not aware of how long it has been since I changed the furnace filter, until I start having fluid build in my lungs, I have a persistent lump of mucus in my throat that will not clear. I cough from time to time, and I may sneeze a bit. When these symptoms become recognizable, I go look at the date on the furnace filter and say "WOW, has it been really THAT long?? Look at that thick layer of dust." This is usually 2-3 months with most pleated filters, but seasonal pollens and molds can accelerate the filter change cycle. How strange. Most bodies would say "Hey, it's too cold in here!!!" as the filter clogs and furnace airflow slows, even though clogged filters filters better. Nick |
Furnace Filters on Steroids
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Furnace Filters on Steroids
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Furnace Filters on Steroids
z wrote:
wrote: Robert Gammon wrote: The HEPA filter I was discussing puts a ZERO pressure drop on your HVAC system as the one I described has its OWN 1HP ECM2 fan inside... A hideous waste of energy. Use a 2 watt Envirosept filter instead. Nick I put a K&N filter in and find I get much better performance. (joke). Almost anything works better than Envirosept. HVAC service says HATE these things as SO much stuff gets onto the AC evaporator coil. Several web sites have commented on this. |
Furnace Filters on Steroids
Robert Gammon wrote:
Almost anything works better than Envirosept. HVAC service says HATE these things as SO much stuff gets onto the AC evaporator coil... Maybe they didn't plug them in. A lot of HVAC techs are stupid. Nick |
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