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Post by WillyCKH on Aug 23, 2017 13:31:21 GMT -5
Hello everyone! I'd like to share my newly built Laminar Flow Hood with you. It is a small unit, about one cubic feet of working volume. The airflow is powered by a bathroom fan, which is pretty loud but gets the job done. The designed parts are printed with my 3D printer, PLA material. A HEPA filter is used for filtering the air, the effectiveness of the filter will be tested with an optical dust sensor later. The light is optional, I'm using a Cold Cathode Light Tube to make it more sci-fi like. Overall, I'm very happy with the build and hopefully the effectiveness will be verified to be great. Hope to start doing some TC works in there soon! What do you think? Cheers, Willy The buildNice and cozy: The Box and the Fan: The rear view: 3D modelDi-metric View: Front view: Rear view: Top view:
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Post by lloyd on Aug 23, 2017 15:19:30 GMT -5
Always good to see some quality DIY.
Comments:
The fan intake seems to have a dark space at the bottom. I hope there is no space for air to bypass the filter.
I would put a pre-filter up-wind from the HEPA filter before the first use. This will preserve the HEPA and decrease contamination at a small cost to the air pressure feeding the HEPA filter. This pre-filter should be regularly cleaned or changed.
The filter area is small compared to the hood cross-section. This will lead to non-linear flow off-center and dead volume at the back peripheral to the filter.
I hope you compared the static pressures required by the filters to that which your fan can provide. You should have room for error.
You should have a dust cover when it is not in use.
Measure the air flow at the hood exit, it should be 100 100 ft/min.
Before trying TC, take containers with sterile medium. Leave the hood on for 30 minutes. Take the lids off in the center of the hood. Leave the containers for 30 minutes. Put the lids back. Put the containers in a clean Ziploc bag for 2 weeks at room temperature. If there's no growth, you've succeeded.
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Post by WillyCKH on Aug 23, 2017 16:17:03 GMT -5
Hi Lloyd, That is the sealing foam (in color black) that comes with the filter, it is not a dark space. There is no air leak as far as I can find It is a good idea to have a pre-filter. I'll try to look for one! Thanks for the testing method, I'll be doing that! Cheers, Willy PS: How long should I wait after pressure cooking the medium to verify that it is sterile?
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Post by lloyd on Aug 23, 2017 16:38:20 GMT -5
As soon as it cools to room temperature. Don't forget the air-flow test.
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Post by WillyCKH on Aug 23, 2017 16:43:10 GMT -5
How should I measure the air flow? What is fps stands for?
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Post by WillyCKH on Aug 23, 2017 19:36:16 GMT -5
Updates: I made a filter cover as Lloyd suggested Doubled up the filter, since they are pretty cheap (~$5), I can afford to replace them up from time to time. Plus it is very easy to replace the filter(s) too.
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Post by lloyd on Aug 23, 2017 19:59:19 GMT -5
I may have confused you. The HEPA filter should not be covered in any way on the operator side. There should be a prefilter on the air intake end. I would not use a HEPA filter for the prefilter. It would not increase the utility of the first HEPA filter and it would provide a significant resistance to airflow which would interfere with proper and sufficient laminar flow. If the HEPA filters are cheap (are you sure it has proper specifications?) and easy to install, then you might leave out the prefilter (which are cheap and easily available). Here's my LFH: www3.sympatico.ca/lloyd.gordon3/home_made_laminar_flow_hood.htmThis is the website (excellent) I used to help build my LFH: www.fungifun.org/English/FlowhoodI read somewhere that 100 foot per minute is just enough to make an alcohol lamp flame go almost horizontal. I bought a cheap and accurate airflow meter which I use now.
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Post by WillyCKH on Aug 23, 2017 20:47:53 GMT -5
I tried it with a lighter, the flame goes horizontal, so I guess the air flow is enough There is a 10% improvement in the dust sensor reading after stacking the two filters together, so I might leave it for now. I love your build, Lloyd, your LFH was my inspiration to build mine. Willy
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Post by lloyd on Aug 23, 2017 23:18:37 GMT -5
I'm inspired that I inspired you 😁
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Post by WillyCKH on Aug 28, 2017 14:09:01 GMT -5
Open medium test is still on-going to verify the effectiveness of the LFH... While waiting impatiently, I have placed two Byblis liniflora seeds (planted 5 days ago) in one container, and today there is one germinated! Sorry for the crappy picture, PP container is hard to see through. I think glass jars are the best but they take up a lot of space.
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Post by WillyCKH on Aug 29, 2017 11:22:57 GMT -5
It's Alive and growing!
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Post by Samskwatch on Aug 29, 2017 12:06:53 GMT -5
Well done Willy!!
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Post by WillyCKH on Aug 30, 2017 21:22:33 GMT -5
My culture is growing, no fluffies! Though only 1 out of the 2 Byblis liniflora seeds is growing, I'm happy.
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Post by WillyCKH on Sept 1, 2017 11:58:30 GMT -5
10 days old! I think it's safe to call this culture the first success
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Post by vraev on Sept 1, 2017 13:04:55 GMT -5
Great job WIlly. Thats awesome.
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