Stained laminar flow HEPA filter question
 

Hi to all!

Maybe some kind soul can help me out: ive recently bought a used laminar flow hood. Everything looks great, except the HEPA seems to have a huge humidity stain (i don´t know if thats the right word... it has a big sort of brown stain)...

as the vendor told me, its been sitting in a garage for like 15 years... everything works great and it was a real bargain, im just wondering if i should change the hepa for a brand new one or the stain will not be a problem...

i can post a photo too... please help! it will be greatly appreciated! excuse my english :P

best regards

I would have changed the filter! 15 years is a long time and a lot of thing could have grown on the "clean" side of the filter.
I would not trust it but why not try it. You will see if it is bad very fast as alot of things will start growing in your "sterile" medium.

a water stain on a HEPA filter in an environment meant for sterile work can't be good. I would change the filter and try to clean out the duct work as much as possible. 15 yrs is a long time to be sitting around.
Nick

actually, ive looked closer and its a reddish stain... i think ill take the whole thing out of the hood and take a better look... it may have been a spill of chemicals. the person who sold it to me said it used to be part of a home laboratory... its a really nasty red stain

thx magnus! i might just have to try and see what happens... cirillonb: maybe its not water! i know it would be nasty to have some kind of mold or fungus growing on your HEPA lol (is that possible?)... maybe someone spilled some red chem over it hummm

by duct u mean the space around the blower at the back? luckily the blower looks great! i will scrub the whole thing :)

i was just asking cause HEPAs cost quite a bit in my country!

thx a lot for the help!