Plasma Exhaust Hood/Ventilation systems

[DRM812]

Anyone use an exhaust hood over their table?

I am looking for ideas about different types of exhaust/ventilation systems. Even homemade systems.

Right now I use an industrial fan and some smaller fans to move the smoke from cutting out my garage doors. This is fine during the Spring/Summer and a portion of the fall but during the winter months in upstate NY, I want a better solution.

I have a window directly in back of my table which I was thinking I could pipe the exhaust out of. My CNC Plasma table is equipped with a water table but it is still pretty smokey.

I should mention I am on a budget...I know some of these systems can get pretty pricey.

[ScottRa]

You could try your local HVAC dealer. I pulled the fan out of an older heat pump unit when the folks were replacing theirs. They were just going to scrap it. I’ve seen these used in shops and garages as cooling fans as they move quite a bit of air and the squirrel cage design is fairly quiet and compact The one I have happens to be 220v which I would venture is common with heat pumps because of the backup/defrost heating elements use that. It doesn’t draw much current wise, and you would have 220 for your plasma and compressor.

Scott

[adbuch]

I use a side exhaust system along with a water tray. It works very well - winter and summer.
David

https://photos.google.com/share/AF1QipN ... NHQVd3V3JB

[THEHENRYCOMPANYLLC]

@ADBUCH what do you do for make up air ? Especially during with winter. I've been doing my homework for months on and off and the cold weather has caught up with me. It's time I make a decision. I have a water table set up and have a simple fan with 4" duct exhausting outside. I'm dealing with negative air pressure and also already seeing heat loss. I installed a 6" backwards dryer vent to pull in fresh air from outside about 30" off the floor at back of my table. I feel the fresh air coming in when the fan kicks on. But I'm pulling out more air then the fresh air supply I'm bringing in. Also, kudos on your build. Incedible work. I believe I'm going to follow your lead in regards to side draft.

[THEHENRYCOMPANYLLC]

@ADBUCH what do you do for make up air ? Especially during with winter. I've been doing my homework for months on and off and the cold weather has caught up with me. It's time I make a decision. I have a water table set up and have a simple fan with 4" duct exhausting outside. I'm dealing with negative air pressure and also already seeing heat loss. I installed a 6" backwards dryer vent to pull in fresh air from outside about 30" off the floor at back of my table. I feel the fresh air coming in when the fan kicks on. But I'm pulling out more air then the fresh air supply I'm bringing in. Also, kudos on your build. Incedible work. I believe I'm going to follow your lead in regards to side draft.
Top

[adbuch]

@ADBUCH what do you do for make up air ? Especially during with winter. I've been doing my homework for months on and off and the cold weather has caught up with me. It's time I make a decision. I have a water table set up and have a simple fan with 4" duct exhausting outside. I'm dealing with negative air pressure and also already seeing heat loss. I installed a 6" backwards dryer vent to pull in fresh air from outside about 30" off the floor at back of my table. I feel the fresh air coming in when the fan kicks on. But I'm pulling out more air then the fresh air supply I'm bringing in. Also, kudos on your build. Incedible work. I believe I'm going to follow your lead in regards to side draft.
Top

Thanks!! I appreciate your kind words.

I don't worry about make up air. I live in Arizona where the winters are mild, but we can still see low 30's some evenings. My machine shop is well insulated, and I run a 6 ton heat/cool system in the machine shop as needed. This consists of 2 Gree 3 ton mini splits, one at each end of the machine shop. I only run the exhaust system when actually cutting. If needed, I pull makeup air from the main shop into the machine shop. My machine shop is about 1000 sq. ft. The entire shop (including the machine shop) is about 5000 sq. ft. So you could say I've got plenty of indoor air volume to draw from if needed.

The exhaust fan I use for my draft system is fairly small compared to what would be needed for a downdraft system using exhaust fan only with no water tray. Also I keep the table covered except for the area the actual cutting is taking place, providing for better "suction" for the draft system to pull any remaining smoke out of the building. My draft system uses 4" ducting pulling from both sides of the table across the surface of the water.

I based my system on the one built by Keith Fenner, which you can see at his youtube videos.


Here is my setup for comparison. Let me know if you have any specific questions about my build and I will try to answer them.

David
https://photos.app.goo.gl/h8LHufi6frttfGNQA

dhc2 water tray draft system build.jpg

[THEHENRYCOMPANYLLC]

A true engineer. I'd trade weather with you in a second !!!! I'll update you on what I come up with. Thanks for response.

[adbuch]

A true engineer. I'd trade weather with you in a second !!!! I'll update you on what I come up with. Thanks for response.