Leesan Microvent holding tank filters

[blackrose]

Does anyone know if it's possible to "desaturate" an activated charcoal filter element once they stop working by leaving them outside on a dry breezy day for example? 

 

Replacements are quite expensive and my 12 year old element doesn't look any different than when it was brand new.

 

 

[PeterF]

This reply is not aimed at the Leesan product specifically but is more generic.

 

Activated carbon filters adsorb the smell chemicals with a weak chemical bond and this bond will not break just by leaving the filter in clean air, it needs to be broken either by heating the filter to drive off or break the chemicals down or by washing the filter. For this service, soaking them in detergent for 20-30 mins may be enough to remove the adsorbed smells or heating up to 150°C. However, if the carbon is impregnated onto a foam carrier that limits how much you could heat it up.

[TheBiscuits]

13 minutes ago, PeterF said:

However, if the carbon is impregnated onto a foam carrier that limits how much you could heat it up.

 

That's not technically correct - you could heat it up to whatever temperature you like.  Whether it would be useable afterwards is a different question!

[Midnight]

As these filters now cost over £40 and last less than 6 months I have asked an engineering friend to make me a same size metal container with removable lid. Using cheap activated charcoal from a aquarium shop it should in theory do the same job. It should be possible to regenerate the charcoal by removing it and heating it up in an oven. I'll report back if it works.

[PCSB]

Technically you can re-activate activated carbon once it has adsorbed all it can. Leaving it outside won't work nor will washing it. to re-activate it, it needs to be heated up to its activation temperature which is 900c if memory serves so not something easily done. It can be re-activated a few times, but each time its effectiveness will diminish, due to the structure, especially the pore size, changing (gets bigger iirc). 

 

Another option would be to fit an inline filter of some description that allows easy change out of AC or resin based filters. You could also include a spun fabric prefilter to remove particualte matter if desired/needed.

[blackrose]

3 hours ago, TheBiscuits said:

 

That's not technically correct - you could heat it up to whatever temperature you like.  Whether it would be useable afterwards is a different question!

 

Perhaps that's exactly what Peter meant, in which case it's not a different question and he was technically correct. 

[blackrose]

53 minutes ago, PCSB said:

Technically you can re-activate activated carbon once it has adsorbed all it can. Leaving it outside won't work nor will washing it. to re-activate it, it needs to be heated up to its activation temperature which is 900c if memory serves so not something easily done. It can be re-activated a few times, but each time its effectiveness will diminish, due to the structure, especially the pore size, changing (gets bigger iirc). 

 

Another option would be to fit an inline filter of some description that allows easy change out of AC or resin based filters. You could also include a spun fabric prefilter to remove particualte matter if desired/needed.

 

Thanks. What I've ended up doing is filling a fine nylon mesh bag with loose activated carbon (available cheaply online) and shoving it into the LeeSan filter housing instead of the element with a round piece of foam underlay on top. The LeeSan element has foam on the top and bottom so maybe I need to put a doughnut shape piece of the foam underlay at the bottom of the housing too.

 

Let's see if it works.

 

Edited August 14, 2021 by blackrose

[Midnight]

On 14/08/2021 at 15:21, blackrose said:

 

Thanks. What I've ended up doing is filling a fine nylon mesh bag with loose activated carbon (available cheaply online) and shoving it into the LeeSan filter housing instead of the element with a round piece of foam underlay on top. The LeeSan element has foam on the top and bottom so maybe I need to put a doughnut shape piece of the foam underlay at the bottom of the housing too.

 

Let's see if it works.

 

 

 

Did it work?
 

[blackrose]

Yes it did. It's just as good as the expensive LeeSan filter and only costs a few quid.

Edited September 21, 2021 by blackrose

[Midnight]

Good news indeed. My 5 month old Microvent is already failing. That's nearly £10 per month!

Thank you for sharing.

Edited September 22, 2021 by Midnight

[blackrose]

4 minutes ago, Midnight said:

Good news indeed. My 5 month old Microvent is already failing. That's nearly £10 per month!

Thank you for sharing.

 

You need a fairly fine mesh nylon bag otherwise you'll get a lot of fine charcoal dust falling through. You can get big bags of charcoal chippings cheaply on ebay.

[Midnight]

Thank you again. I have a fine mesh bag but as we are still cruising I will try to get some activated carbon charcoal at an aquatic store. We will be visiting Chester shortly there seems to be one near the canal.

[PeterF]

On 21/09/2021 at 18:37, blackrose said:

Yes it did. It's just as good as the expensive LeeSan filter and only costs a few quid.

Have you had a pump out with the bagged charcoal yet as that will be a good test for the breathing ability. I am also interested as I also have one of these.

[jonesthenuke]

I refill the filter for our Dometic Vacuflush with activated carbon granules normally used in cooker hood filters. It works fine and costs peanuts in comparison to OEM price.

[blackrose]

19 hours ago, PeterF said:

Have you had a pump out with the bagged charcoal yet as that will be a good test for the breathing ability. I am also interested as I also have one of these.

 

I don't have a pump out toilet (thankfully!)