Home Made Laminar Flow Hood
With special thanks to my friends at the Ontario Carnivorous Plant Society and this website.
I tried to minimize cost, weight, bulkiness and noise and maximize the size and ease of use of the working area. For the frame I used cheap spruce from Home Depot. The plenum is made of 1/8" fiberboard also from Home Depot. I wish I had thought of corrugated or foam filled plastic board. It would have been much easier to work with. The plexiglass ($20) is from Plastic World in Toronto, 1/16" which they cut for you to size. The fan is a Tjernlund M6 with a matching speed control set to a minimum of 60V (both about $150 with shipping). The HEPA filter is from Home Depot ($75 on sale) 99.97% @ 0.3 micron and it came with 2 pre-filters. I had the screws, glue, caulking, foam weather stripping and odds and ends at home already. I'd guess I spent about $250 altogether. The fan was the most expensive part but I wanted to get a good quality one to keep the noise and vibration down. I tested for 100 CFM with a alcohol flame so it was almost at a right angle but not blown out which was with the speed control almost at minimum. The noise wasn't too bad at all. I tested medium exposed to the air flow for 5, 10, 15 & 20 minutes and incubated it for 2 weeks at 25C with no growth so it seems to work. It took me months of work to make it but I'm proud of " the big box" as it is known in our household.
Speed Control and power cord
Back view and pre-filter that came with the HEPA
Front with some velcro'ed plastic to keep the dust down
Side view with plexiglass
Top view with the HEPA