DIY laminar flow hood filtration question

[grunttruck]

hello everyone, i am building a laminar flow hood for plant tissue culturing and have a question regarding flow and filters. my issue is i want a decent size of work space, that isn't all cramped up. as it stands, a 12"x24" hepa or merv 17 rated filter is pretty expensive, but two 12"x14" filters are not. my question is, would the laminar flow be disrupted by splicing two filters together? assuming i find a pair of filters that have a thin enough trim/border that would make the seam marginal at best, that is, if this makes sense. thoughts?

 

[russ_watters]

Are you going to use a perforated plate to generate the flow pattern? If so, the seam between the filters won't matter.

 

[grunttruck]

Are you going to use a perforated plate to generate the flow pattern? If so, the seam between the filters won't mat

cheers for the reply.. the plan i was following didn't mention any perforated plates, but i suppose i could include them. would egg crate work? or even putting the hepa filters before a furnace prefilter of the same combined size?

 

[russ_watters]

Furnace pre-filter would work OK, but, how big is this seam? It may not be a big problem. And do you have a drawing of the hood?

 

[grunttruck]

Furnace pre-filter would work OK, but, how big is this seam? It may not be a big problem. And do you have a drawing of the hood?

i'm reckoning the seam will be about 1/4" max

here's a couple pictures from the plans. the first is the filter box without the filter and fan housing, the second includes those. this plan is for a 2'x4' filter, but i will be scaling it down