Great video. I purchased this filter in April and was wondering if it would actually last a year. And especially good to know the airflow numbers were still good after 1 year.
Gotta love citizen science! Fun experiment. However, there were a lot of variables unaccounted for. 1- a dirty filter will clean the air more thoroughly but at the expense of airflow. So the air the furnace is moving will be cleaner with the old filter but there will be less cfm. Whether this will lead to overall cleaner air is one of those sometimes, maybe , it depends situations. 2- your airflow measurements you mention in the comments here was actually air velocity not air flow. So when you say the velocity increased from 314fpm to 374fpm, that’s not the airflow. You need to multiply those numbers by the duct area to get air flow. So it may have been a sizable increase in airflow or not so much but we can’t tell from what you reported. 3- your house is very leaky. Mine is 0.5ACH - yes much tighter than normal, but a small change in wind or outdoor PM and you could dramatically change your infiltration rate which could have skewed your numbers quite a bit either before or after. Especially with your furnace running on low speed it might only be cleaning 400cfm. But with that leaky house the outdoor infiltration might have changed by a significant amount during your test depending on the wind. An extra 50 cfm of air at the us epa aqi of 114 is about 40micrograms of pm 2.5 per m3 - means you can add a lot of pm 2.5 at the same time that you are slowly trying to remove it. Hard to prove the filter change made a difference. aqicn.org/calculator 4-those vane-type anemometers are typically unreliable and difficult to compare. Hopefully you left the anemometer in place without touching it if you want to compare readings before and after. 5- another variable is possibly your furnace fresh air intake connecting the outdoors to the return air plenum. If your furnace moved more air, it will suck in more air from outdoors. This air gets filtered and starts to try and pressurize the house which reduces the unintentional air infiltration of dirty unfiltered air. However your house is leaky so this might not apply. I’m not sure we are closer to knowing if or why the new filter made the air in your house any cleaner. But, what would be interesting is to have measured the total static pressure across the furnace before and after the filter change to see if the pressure stayed within the specs listed inside the furnace door. That’s probably a better indicator to indicate when to change the filter. Dwyer sells a static pressure probe kit and magnahelic gauges just for this purpose. These are not intended to be critical comments about your experiment. Just my ramblings off the cuff after watching your video. Glad to see you taking action against pm 2.5! Merry Christmas!
Dave - have you tried vacuum over the old filter to remove some debris (maybe blow some air through the filter in reverse) - be interesting to see the impact on results...
Oh, I take that back the airflow was 314ft/min now it is 374ft/min after the filter change, so the new filter did allow for more airflow! Sorry about the confusion.
OK it has been one year and I just replaced another filter, I measured the airflow before and after, it was exactly the same this time. The filter looked much cleaner this year.
A subtle change of direction but great to see you back Dave!
Man I'm glad you're good.
haven't sen a video from you in quite a while but still subbed from the T3i days.
Great video. I purchased this filter in April and was wondering if it would actually last a year. And especially good to know the airflow numbers were still good after 1 year.
Gotta love citizen science! Fun experiment. However, there were a lot of variables unaccounted for.
1- a dirty filter will clean the air more thoroughly but at the expense of airflow. So the air the furnace is moving will be cleaner with the old filter but there will be less cfm. Whether this will lead to overall cleaner air is one of those sometimes, maybe , it depends situations.
2- your airflow measurements you mention in the comments here was actually air velocity not air flow. So when you say the velocity increased from 314fpm to 374fpm, that’s not the airflow. You need to multiply those numbers by the duct area to get air flow. So it may have been a sizable increase in airflow or not so much but we can’t tell from what you reported.
3- your house is very leaky. Mine is 0.5ACH - yes much tighter than normal, but a small change in wind or outdoor PM and you could dramatically change your infiltration rate which could have skewed your numbers quite a bit either before or after. Especially with your furnace running on low speed it might only be cleaning 400cfm. But with that leaky house the outdoor infiltration might have changed by a significant amount during your test depending on the wind. An extra 50 cfm of air at the us epa aqi of 114 is about 40micrograms of pm 2.5 per m3 - means you can add a lot of pm 2.5 at the same time that you are slowly trying to remove it. Hard to prove the filter change made a difference. aqicn.org/calculator
4-those vane-type anemometers are typically unreliable and difficult to compare. Hopefully you left the anemometer in place without touching it if you want to compare readings before and after.
5- another variable is possibly your furnace fresh air intake connecting the outdoors to the return air plenum. If your furnace moved more air, it will suck in more air from outdoors. This air gets filtered and starts to try and pressurize the house which reduces the unintentional air infiltration of dirty unfiltered air. However your house is leaky so this might not apply.
I’m not sure we are closer to knowing if or why the new filter made the air in your house any cleaner. But, what would be interesting is to have measured the total static pressure across the furnace before and after the filter change to see if the pressure stayed within the specs listed inside the furnace door. That’s probably a better indicator to indicate when to change the filter. Dwyer sells a static pressure probe kit and magnahelic gauges just for this purpose.
These are not intended to be critical comments about your experiment. Just my ramblings off the cuff after watching your video. Glad to see you taking action against pm 2.5!
Merry Christmas!
Dave - have you tried vacuum over the old filter to remove some debris (maybe blow some air through the filter in reverse) - be interesting to see the impact on results...
I was thinking the same thing, that would be a fun test to try.
Dave Dugdale 2nd RUclips Channel You stopped doing your other channel Doug?
@@DrunkDelilahBrewery No, but I will be changing direction soon.
Dave Dugdale great - we miss your videos !!!
Another post here in the same direction: Dave, please continue to post (content), all your content has been and will continue, admired !!
You have an air leak. The fiberglass, bugs and excessive dust are all red flags. Did you ever get this figured out? I work on these full time.
It has been a year and I just replaced the filter again, this time it was much cleaner without the bugs and excessive dust. Not sure why.
I missed it. Did the air flow improve
Yes, the PM2.5 levels dropped, I thought I said that at the end of the video.
But the airflow remained the same if that is what you asked.
Oh, I take that back the airflow was 314ft/min now it is 374ft/min after the filter change, so the new filter did allow for more airflow! Sorry about the confusion.
OK it has been one year and I just replaced another filter, I measured the airflow before and after, it was exactly the same this time. The filter looked much cleaner this year.
I came for your curved vs. flat screen review, now I remember another of my "To Do" list items. Thanks for nothing. ;)