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Post by tom on Dec 2, 2007 15:45:21 GMT -5
I've finally done myself a small laminar flowhood Mainly for orchids TC, all i need is to do some sterile vessels to test its efficiency to produce a sterile area for working yeah! Wish me luck!
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Post by lloyd on Dec 2, 2007 17:48:58 GMT -5
Congratulations. Let's see some pictures. I'm thinking of building one.
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Post by tom on Dec 2, 2007 18:06:19 GMT -5
I'll try to take some tonight
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Post by tom on Dec 2, 2007 18:53:12 GMT -5
I had some plywood lying around and a unused squirrel cage, so i've decided to build a relatively cheap one using those material, despite i would reduce my working space to about 10" x 10", but it should be enough for an hobbyist-scale TC activities. My fan is running at 140 cfm and the filter has been found at Canadian Tires for 50$. Filter: Bionaire ULPA filter no UA0860, blcking 99,999% of particles down to 0,1 microns Fan: Dayton model 4C442 I've not matched the filter with the fan, as recommanded by some LMH instruction/website/book. View as 'closed for transportation or storage' Closed, but placed as for operation Top view/Air intake. A prefilter will be applied here. You can see that all joints have been sealed with caulking. Front view of the bottom. The filter hasn't been placed. The air entrace from the blower can be seen in upper left. ULPA filter seen separatly and partly in place (not pushed all the way since it will be too tight for easy removal and i still need to work inside). The filter is originally designed to work in its 'reverse sense' so it's why you can see a prefilter. It will be remove to avoid the disturbance of the air flow. Some works still need to be done, such as applying plastic wood to patch some screw holes (the plywood have been used before), to make the whole thing as air tight as possible. Spraying some kind of varnish inside is also in my mind, to make the air flow easier and prevent trapping dust inside, but i dont think it would be necessary. The wood material is far from being the best for this type of application, but i had it for free, so it wasn't much a question... I'll expose some sterile culture vessels with media to the LFH for 15-20 min before closing the lid back, to see if any contaminants occurs, hopefully this week-end. If everything is fine, trust me, my appartment will smell bleach all x-mas holidays lol. Lloyd' if you have any further questions, comments, needed specs, just ask it will be a pleasure to help. Hope i've inspired a few ones....
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Post by lloyd on Dec 2, 2007 22:11:22 GMT -5
Tom: Looks like a great job. I thought you couldn't do any electrical work! What kind of prefilter are you going to use for the squirrel cage fan? I guess the dimensions of the HEPA filter determine the size of the work chamber. Is there a relation between the cfm of the squirrel fan and the size of the HEPA filter?
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Post by vraev on Dec 2, 2007 22:58:57 GMT -5
holy! very veyr nice construction there tom. wow! huh! I would be happy to get an aquarium or make a nice enclousure for my neps with fans like that.
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Post by tom on Dec 3, 2007 11:13:25 GMT -5
thanks!
About the wiring, i had the fan lying around, already wired, but as far as i know, it's not much fuss to wire such thing (2 prongs and no others devices to install in between).
there is a relation between static pressure of the filter, filter dimension and fan air flow to achieve the desired airflow in the working area. I found a few graphs and advices on mushrooms growing website/books and orchid TC website. I'll try to find them back tonight.
as for the prefilter, i think a furnace prefilter will be perfect and cheap.
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Post by PingKing on Dec 3, 2007 12:45:22 GMT -5
very nice
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Post by tom on Dec 3, 2007 15:24:57 GMT -5
here's a link on the filter vs fan matching procedure, quite helpful page btw www.fungifun.org/English/Flowhoodunfortunatly, static pressure information wasnt available for the filter i found. HEPA filter can also be bought (and lfh as well) from www.fungiperfecti.comin the air filtration tools section, but the shipping price to Canada is a bit prohibitive. Nevertheless, it's a source I would trust.
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Post by lloyd on Dec 3, 2007 16:30:56 GMT -5
Thanks Tom, you've inspired me to plan one of these. I hope my carpentry skills will be up to your standards. Maybe my wife will help me, she's very good at carpentry and makes her own furniture.
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Post by tom on Dec 3, 2007 18:00:54 GMT -5
my standards? I am as skillful with woods than i am with electrical wiring... ie a total novice, so you shouldn't have much troubles to make a better/fancier LFH than mine
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Post by tom on Dec 15, 2007 8:40:40 GMT -5
So far so good, i got no contamination after 1 week.
;D ;D ;D
The airflo is too strong though, i can definatly feel the air current and the flame of my alcohol burner bent terribly toward me. I'll try wire a dimmer to ajust it (thanks to rick keens comments)
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Post by lloyd on Dec 15, 2007 11:38:45 GMT -5
Congratulations on your sterility success.
I did some checking. Your squirrel cage fan motor is almost certainly brushless. It should say on the motor label if it is brushless or not. If it is brushless then dimmers will not change the speed and are not recommended.
Have you thought of a small variable exhaust hole between the fan and the HEPA filter? That would be an effective and easy way to reduce the air-flow.
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Post by vraev on Dec 15, 2007 21:40:51 GMT -5
very nice Tom. Whats your first plan in tissue culture?? ;D
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Post by tom on Dec 16, 2007 14:11:50 GMT -5
Lloyd: i know we had problem when we tried a dimmer in the past on this one (sparks) but it was a light dimmer, not a fan dimmer... I'll check for the inbformations you mentionned... The air hole in the inner chamber was my second option, some TCers had done this when they had the same problem that i do. Vraev: now that sterility seems OK, i plan to replate my old experiments that i left aside for a year: Darlingtonia, Heliamphora minor, S.purp, Drosophyllum (one tiny sickly looking plant left). Hopefully, they'll grow back nicely and I'll send some to Keehn's carnivores, for a back-up and allowing him to flood Canada with this marvelous plants, as i dont have neither time, nor space to do it lol... After that, we will see... but VFT cultivars would be nice, and i have a 'revenge' to take on Byblis gigantea... and a try on petiolaris-complex sundews would be interesting ... and why not epiphytic utrics.... and...
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