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#41
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Furnace filters
On Mon, 11 Feb 2019 16:35:25 -0500, Tekkie®
wrote: Clare Snyder posted for all of us... On Wed, 6 Feb 2019 14:02:53 -0500, Tekkie® wrote: Frank posted for all of us... On 2/4/2019 7:23 PM, Ed Pawlowski wrote: For the first time in 53 years of owning homes, my new house has a furnace and uses filters.* It takes a 1" filter. I see prices can vary considerably but is a MERV 8 and MERV 8 regardless of the brand?* Should I use MERV 8 or MERV 11?* We have no pets. I see filters with MERV 11 rating from $9.95 ($7.45ea by a dozen) to $14.50. Any real difference if they have the same rating? Discount filters seems cheapest. I use air filters and had never heard the term MERV so looked up your question: https://airexpertsnj.com/knowledge/e...erv-11-filters Prompted me to look at the filters I'm using and now see that they are MERV 11. Don't know about price difference but sometimes filter may collapse somewhat and more expensive filter might be sturdier. I am no filter expert but IIRC if the MERV number is increased then possibly the blower motor can overload. Research the info on your system to determine the suitability. Restricting airflow does NOT overload a blower motor. Restricted filters restrict the amount of air moved REDUCING load on the blower motor. Youknew that and forgot - right "tekkie"? If I am wrong then teach me. I have always been willing to listen. Plug your vacuum hose and listen to the pitch of the motor. It speeds up. Power is consumed by moving air. Block the filter and you move less air, therefore using less power. It's not like a positive displacement pump like a compressoe - where you WOULD be correct. One problem with blocked air filters and plugged vacuums (without a bypass motor) is overheating because less air moves across the motor to cool it. It overheats not from overloading but undercooling. I hope that "clare"ifies things for you. Don't take my word for it. look at https://www.cagi.org/news/HowInletCo...pressors. pdf look at the intake pressure section on page 3 - just after figure 2. |
#42
Posted to alt.home.repair
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Furnace filters
Clare Snyder writes:
On Mon, 11 Feb 2019 16:35:25 -0500, Tekkie® wrote: Clare Snyder posted for all of us... On Wed, 6 Feb 2019 14:02:53 -0500, Tekkie® wrote: Frank posted for all of us... On 2/4/2019 7:23 PM, Ed Pawlowski wrote: For the first time in 53 years of owning homes, my new house has a furnace and uses filters.* It takes a 1" filter. I see prices can vary considerably but is a MERV 8 and MERV 8 regardless of the brand?* Should I use MERV 8 or MERV 11?* We have no pets. I see filters with MERV 11 rating from $9.95 ($7.45ea by a dozen) to $14.50. Any real difference if they have the same rating? Discount filters seems cheapest. I use air filters and had never heard the term MERV so looked up your question: https://airexpertsnj.com/knowledge/e...erv-11-filters Prompted me to look at the filters I'm using and now see that they are MERV 11. Don't know about price difference but sometimes filter may collapse somewhat and more expensive filter might be sturdier. I am no filter expert but IIRC if the MERV number is increased then possibly the blower motor can overload. Research the info on your system to determine the suitability. Restricting airflow does NOT overload a blower motor. Restricted filters restrict the amount of air moved REDUCING load on the blower motor. Youknew that and forgot - right "tekkie"? If I am wrong then teach me. I have always been willing to listen. Plug your vacuum hose and listen to the pitch of the motor. It speeds up. Power is consumed by moving air. Block the filter and you move less air, therefore using less power. It's not like a positive displacement pump like a compressoe - where you WOULD be correct. One problem with blocked air filters and plugged vacuums (without a bypass motor) is overheating because less air moves across the motor to cool it. It overheats not from overloading but undercooling. I hope that "clare"ifies things for you. Don't take my word for it. look at https://www.cagi.org/news/HowInletCo...pressors. pdf look at the intake pressure section on page 3 - just after figure 2. I thought we were discussing furnace filters. What does an air compressor have to do with it? The facts are that the air handler in the furnace needs to work _harder_ when the filter gets dirty. Working _harder_ requires more current. |
#43
Posted to alt.home.repair
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Furnace filters
On Tuesday, February 12, 2019 at 9:14:49 AM UTC-5, Scott Lurndal wrote:
Clare Snyder writes: On Mon, 11 Feb 2019 16:35:25 -0500, Tekkie® wrote: Clare Snyder posted for all of us... On Wed, 6 Feb 2019 14:02:53 -0500, Tekkie® wrote: Frank posted for all of us... On 2/4/2019 7:23 PM, Ed Pawlowski wrote: For the first time in 53 years of owning homes, my new house has a furnace and uses filters.Â* It takes a 1" filter. I see prices can vary considerably but is a MERV 8 and MERV 8 regardless of the brand?Â* Should I use MERV 8 or MERV 11?Â* We have no pets. I see filters with MERV 11 rating from $9.95 ($7.45ea by a dozen) to $14.50. Any real difference if they have the same rating? Discount filters seems cheapest. I use air filters and had never heard the term MERV so looked up your question: https://airexpertsnj.com/knowledge/e...erv-11-filters Prompted me to look at the filters I'm using and now see that they are MERV 11. Don't know about price difference but sometimes filter may collapse somewhat and more expensive filter might be sturdier. I am no filter expert but IIRC if the MERV number is increased then possibly the blower motor can overload. Research the info on your system to determine the suitability. Restricting airflow does NOT overload a blower motor. Restricted filters restrict the amount of air moved REDUCING load on the blower motor. Youknew that and forgot - right "tekkie"? If I am wrong then teach me. I have always been willing to listen. Plug your vacuum hose and listen to the pitch of the motor. It speeds up. Power is consumed by moving air. Block the filter and you move less air, therefore using less power. It's not like a positive displacement pump like a compressoe - where you WOULD be correct. One problem with blocked air filters and plugged vacuums (without a bypass motor) is overheating because less air moves across the motor to cool it. It overheats not from overloading but undercooling. I hope that "clare"ifies things for you. Don't take my word for it. look at https://www.cagi.org/news/HowInletCo...pressors. pdf look at the intake pressure section on page 3 - just after figure 2. I thought we were discussing furnace filters. What does an air compressor have to do with it? The facts are that the air handler in the furnace needs to work _harder_ when the filter gets dirty. Working _harder_ requires more current. It would seem to me there are two competing factors. Clare says that a fan with a dirty filter moves less air, so that means less current. That certainly would be true, all things being equal. You raise a good point though, that it's not necessarily just about how much air is moved, but the force required to pull what air it's moving. If I'm lifting 30 1 lb balls a minute off the floor, it takes X power. If I'm lifting only 20 1 lb balls a minute, it takes a third less power, 0.66X. But if I'm lifting 20 1 lb balls and they are being held back now with a small spring, representing a dirty filter, then the power used will be more than .66X. I think in the real world, for an ordinary blower motor, with a restricted filter it does wind up using less power with a clogged filter. Ultimately if you clog if enough, the blower winds up cavitating and the power drops even more. The new ECM, variable speed blowers though, I think behave differently and may use more power with a clogged filter. |
#44
Posted to alt.home.repair
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Furnace filters
"trader_4" wrote in message ... On Tuesday, February 12, 2019 at 9:14:49 AM UTC-5, Scott Lurndal wrote: Clare Snyder writes: On Mon, 11 Feb 2019 16:35:25 -0500, Tekkie® wrote: Clare Snyder posted for all of us... On Wed, 6 Feb 2019 14:02:53 -0500, Tekkie® wrote: Frank posted for all of us... On 2/4/2019 7:23 PM, Ed Pawlowski wrote: For the first time in 53 years of owning homes, my new house has a furnace and uses filters. It takes a 1" filter. I see prices can vary considerably but is a MERV 8 and MERV 8 regardless of the brand? Should I use MERV 8 or MERV 11? We have no pets. I see filters with MERV 11 rating from $9.95 ($7.45ea by a dozen) to $14.50. Any real difference if they have the same rating? Discount filters seems cheapest. I use air filters and had never heard the term MERV so looked up your question: https://airexpertsnj.com/knowledge/e...erv-11-filters Prompted me to look at the filters I'm using and now see that they are MERV 11. Don't know about price difference but sometimes filter may collapse somewhat and more expensive filter might be sturdier. I am no filter expert but IIRC if the MERV number is increased then possibly the blower motor can overload. Research the info on your system to determine the suitability. Restricting airflow does NOT overload a blower motor. Restricted filters restrict the amount of air moved REDUCING load on the blower motor. Youknew that and forgot - right "tekkie"? If I am wrong then teach me. I have always been willing to listen. Plug your vacuum hose and listen to the pitch of the motor. It speeds up. Power is consumed by moving air. Block the filter and you move less air, therefore using less power. It's not like a positive displacement pump like a compressoe - where you WOULD be correct. One problem with blocked air filters and plugged vacuums (without a bypass motor) is overheating because less air moves across the motor to cool it. It overheats not from overloading but undercooling. I hope that "clare"ifies things for you. Don't take my word for it. look at https://www.cagi.org/news/HowInletCo...pressors. pdf look at the intake pressure section on page 3 - just after figure 2. I thought we were discussing furnace filters. What does an air compressor have to do with it? The facts are that the air handler in the furnace needs to work _harder_ when the filter gets dirty. Working _harder_ requires more current. It would seem to me there are two competing factors. Clare says that a fan with a dirty filter moves less air, so that means less current. That certainly would be true, all things being equal. You raise a good point though, that it's not necessarily just about how much air is moved, but the force required to pull what air it's moving. If I'm lifting 30 1 lb balls a minute off the floor, it takes X power. If I'm lifting only 20 1 lb balls a minute, it takes a third less power, 0.66X. But if I'm lifting 20 1 lb balls and they are being held back now with a small spring, representing a dirty filter, then the power used will be more than .66X. I think in the real world, for an ordinary blower motor, with a restricted filter it does wind up using less power with a clogged filter. Thats mad and trivial to prove by measuring the power the blower is taking with a clogged filter and with the new filter. Ultimately if you clog if enough, the blower winds up cavitating and the power drops even more. Blowers dont get that clogged. The new ECM, variable speed blowers though, I think behave differently and may use more power with a clogged filter. Even madder. |
#45
Posted to alt.home.repair
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Furnace filters
Clare Snyder posted for all of us...
On Mon, 11 Feb 2019 16:35:25 -0500, Tekkie® wrote: Clare Snyder posted for all of us... On Wed, 6 Feb 2019 14:02:53 -0500, Tekkie® wrote: Frank posted for all of us... On 2/4/2019 7:23 PM, Ed Pawlowski wrote: For the first time in 53 years of owning homes, my new house has a furnace and uses filters.* It takes a 1" filter. I see prices can vary considerably but is a MERV 8 and MERV 8 regardless of the brand?* Should I use MERV 8 or MERV 11?* We have no pets. I see filters with MERV 11 rating from $9.95 ($7.45ea by a dozen) to $14.50. Any real difference if they have the same rating? Discount filters seems cheapest. I use air filters and had never heard the term MERV so looked up your question: https://airexpertsnj.com/knowledge/e...erv-11-filters Prompted me to look at the filters I'm using and now see that they are MERV 11. Don't know about price difference but sometimes filter may collapse somewhat and more expensive filter might be sturdier. I am no filter expert but IIRC if the MERV number is increased then possibly the blower motor can overload. Research the info on your system to determine the suitability. Restricting airflow does NOT overload a blower motor. Restricted filters restrict the amount of air moved REDUCING load on the blower motor. Youknew that and forgot - right "tekkie"? If I am wrong then teach me. I have always been willing to listen. Plug your vacuum hose and listen to the pitch of the motor. It speeds up. Power is consumed by moving air. Block the filter and you move less air, therefore using less power. It's not like a positive displacement pump like a compressoe - where you WOULD be correct. One problem with blocked air filters and plugged vacuums (without a bypass motor) is overheating because less air moves across the motor to cool it. It overheats not from overloading but undercooling. I hope that "clare"ifies things for you. Don't take my word for it. look at https://www.cagi.org/news/HowInletCo...pressors. pdf look at the intake pressure section on page 3 - just after figure 2. Okay, I looked at HVAC TALK and they measured the amp draw which was less with a dirty filter. They mentioned two types of motors. I stand corrected. I was thinking? that the motor would not be running at rated cooling and tend to overheat over time and crap out. -- Tekkie |
#47
Posted to alt.home.repair
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Furnace filters
On Tue, 12 Feb 2019 14:23:06 -0500, Tekkie®
wrote: Clare Snyder posted for all of us... On Mon, 11 Feb 2019 16:35:25 -0500, Tekkie® wrote: Clare Snyder posted for all of us... On Wed, 6 Feb 2019 14:02:53 -0500, Tekkie® wrote: Frank posted for all of us... On 2/4/2019 7:23 PM, Ed Pawlowski wrote: For the first time in 53 years of owning homes, my new house has a furnace and uses filters.* It takes a 1" filter. I see prices can vary considerably but is a MERV 8 and MERV 8 regardless of the brand?* Should I use MERV 8 or MERV 11?* We have no pets. I see filters with MERV 11 rating from $9.95 ($7.45ea by a dozen) to $14.50. Any real difference if they have the same rating? Discount filters seems cheapest. I use air filters and had never heard the term MERV so looked up your question: https://airexpertsnj.com/knowledge/e...erv-11-filters Prompted me to look at the filters I'm using and now see that they are MERV 11. Don't know about price difference but sometimes filter may collapse somewhat and more expensive filter might be sturdier. I am no filter expert but IIRC if the MERV number is increased then possibly the blower motor can overload. Research the info on your system to determine the suitability. Restricting airflow does NOT overload a blower motor. Restricted filters restrict the amount of air moved REDUCING load on the blower motor. Youknew that and forgot - right "tekkie"? If I am wrong then teach me. I have always been willing to listen. Plug your vacuum hose and listen to the pitch of the motor. It speeds up. Power is consumed by moving air. Block the filter and you move less air, therefore using less power. It's not like a positive displacement pump like a compressoe - where you WOULD be correct. One problem with blocked air filters and plugged vacuums (without a bypass motor) is overheating because less air moves across the motor to cool it. It overheats not from overloading but undercooling. I hope that "clare"ifies things for you. Don't take my word for it. look at https://www.cagi.org/news/HowInletCo...pressors. pdf look at the intake pressure section on page 3 - just after figure 2. Okay, I looked at HVAC TALK and they measured the amp draw which was less with a dirty filter. They mentioned two types of motors. I stand corrected. I was thinking? that the motor would not be running at rated cooling and tend to overheat over time and crap out. That is true of cheap vacuums which are cooled by the exhaust air going through the motor, which is why tangential bypass motors are used in high quality vacuums. A tangential bypass motor actually cools BETTER when the airflow is restricted,(because the cooling fan is running faster and moving more air) while a flow through motor WILL overheat and burn out with a blocked hose or full bag. |
#48
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Furnace filters
It depends on the design of the impeller blades.
Most vacuum cleaners speed up when the airflow is blocked. But if the blades are of a different design, it could be the other way round. If you are a real geek, get a couple of probe thermometers. Stick one in the intake plenum and one in the output plenum and even amhigh temp one in the flue. Mark down what the normal temps are and if anything changes you know something needs fixed. Works for AC too. M |
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