Cloth HEPA Bag Tests

In this latest round of tests, I wanted to answer two questions:

1) How much performance do you lose by re-using a cloth HEPA bag and
2) How much performance do you lose by completely filling a cloth HEPA bag.

My test machines of choice (all in mint and/or fully restored condition) were a 1980 Lux 1401-B, a 1987 Kirby Heritage II Legend and a 2012 Hoover Temp Widepath. My cloth HEPA bags of choice were the Perfect for the Lux, the OEM Kirby white cloth for the Heritage and the Crucial white bags for the Hoover.
Airflow measuring devices were the ubiquitous Baird airflow meter and a GM8901 anemometer.

Results:

The Hoover Tempo Widepath experienced a 3 CFM loss when re-using a bag and a 15 CFM loss when the bag was full. These measurements were taken at the body, not the hose end.

The Kirby Heritage II Legend experienced a 10 CFM loss when re-using a bag and a 17 CFM loss when the bag was ž full. As it took me several months to accumulate enough dirt for this test, I was unable to completely fill the Kirbys bag. These measurements were taken at the body, not the hose end.

The Electrolux Olympia One experienced a 7 CFM loss at the hose end when the bag was full. I did not attempt to re-use the Perfect bag this time around.

Comments:

I found out that turning a cloth HEPA bag inside out and blowing all the dust and debris out was a very messy undertaking and I wouldnt normally recommend it. But with airflow losses in the 3-6% (3-10 CFM) range, I have enough proof that the pores in high quality cloth bags arent permanently cloggedat least with my house dirt, which includes some dog hair.

I definitely was surprised that ž to completely full bags still only lost 7-14% (8-17 CFM). The mighty Lux 1401-B still had 79 CFM at the hose end (thats just about what new Rainbows start with). Even though the eject mechanism still works in the 36-year-old beast, a full HEPA cloth bag wouldnt trigger it, but a full 4-ply paper bag will.

Enjoy!

Bill

Photos... < > Photo 1 of 5 View Full Size


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Post# 345831 2/29/2016 at 19:31 (2,971 days old) by wyaple (Pickerington, OH)
Checkrate/Likes 2 In this latest round of tests, I wanted to answer two questions: 1) How much performance do you lose by re-using a cloth HEPA bag and 2) How much performance do you lose by completely filling a cloth HEPA bag. My test machines of choice (all in mint and/or fully restored condition) were a 1980 Lux 1401-B, a 1987 Kirby Heritage II Legend and a 2012 Hoover Temp Widepath. My cloth HEPA bags of choice were the Perfect for the Lux, the OEM Kirby white cloth for the Heritage and the Crucial white bags for the Hoover. Airflow measuring devices were the ubiquitous Baird airflow meter and a GM8901 anemometer. Results: The Hoover Tempo Widepath experienced a 3 CFM loss when re-using a bag and a 15 CFM loss when the bag was full. These measurements were taken at the body, not the hose end. The Kirby Heritage II Legend experienced a 10 CFM loss when re-using a bag and a 17 CFM loss when the bag was ž full. As it took me several months to accumulate enough dirt for this test, I was unable to completely fill the Kirbys bag. These measurements were taken at the body, not the hose end. The Electrolux Olympia One experienced a 7 CFM loss at the hose end when the bag was full. I did not attempt to re-use the Perfect bag this time around. Comments: I found out that turning a cloth HEPA bag inside out and blowing all the dust and debris out was a very messy undertaking and I wouldnt normally recommend it. But with airflow losses in the 3-6% (3-10 CFM) range, I have enough proof that the pores in high quality cloth bags arent permanently cloggedat least with my house dirt, which includes some dog hair. I definitely was surprised that ž to completely full bags still only lost 7-14% (8-17 CFM). The mighty Lux 1401-B still had 79 CFM at the hose end (thats just about what new Rainbows start with). Even though the eject mechanism still works in the 36-year-old beast, a full HEPA cloth bag wouldnt trigger it, but a full 4-ply paper bag will. Enjoy! Bill Photos... < > Photo 1 of 5 View Full Size

Post# 345914 , Reply# 1 3/1/2016 at 08:51 (2,970 days old) by suckolux (Yuba City, CA)
Checkrate/Likes I have the cloth hepa on the legend 2, it does't seem as noticeable when it fill, just keeps working fine! On my Silverado, the difference from their 4 ply to the cloth was night and day! 2 weeks with the paper, I could hear the air flow drop off,it just never seems to happen now, unless its Miele full. I set it on #1 and it will trigger a pop open, but when full. It makes using the machine so much nicer, and the bags last so long, not even sure its more money. Dust smell gone also!

Post# 345917 , Reply# 2 3/1/2016 at 08:55 (2,970 days old) by suckolux (Yuba City, CA)
Checkrate/Likes Thank you for the info Bill! I was only going on sound/ feel before. That Silverado goes to the grave with me! The quasi grandson used it to blow out his computer, and he said oh my god, this thing is a beast! He wants the Legend when I can't push it anymore.

Post# 354479 , Reply# 3 6/24/2016 at 15:18 (2,855 days old) by n0oxy (Saint Louis Missouri, United States)
Checkrate/Likes *reusing bags* Some backpack vacuums can take bags that are open, allowing you to dump them and reuse them a few times. I probably wouldn't do this because of the mess, that's the main reason why I don't like bagless vacuums. I do use the open bags in my backpacks when I can because an open bag probably allows more air flow.

Post# 354481 , Reply# 4 6/24/2016 at 15:24 (2,855 days old) by sebo_fan (Scotland, UK, member AKA ukvacfan, & Nar2)
Checkrate/Likes Good tests. I have reused a SEBO Felix dust bag after brushing it clean and find it will work again. However, the bag can also be washed, dried and installed again.