Sunday, May 30, 2010

Ventilation is Working!

After weeks of work, the new studio is almost up and running! The walls have all been finished and painted, things are arranged, and the ventilation is working.

Here's a summary of the ventilation:


Directly to the right of the bench, not visible in this picture, is a large window where makeup air is currently coming from. Eventually we plan to add ducting from under the bench and directed to the sides between the table and the hood. The weather here is very nice and temp in the studio is generally between 50 and 80F year round, but could get cooler in winter or warmer in summer, especially once the kiln and torch get fired up. So directing most of the makeup directly to the bench should help maintain temperature.


From the hood above the bench, there's a 9" hole in the top, with the vent connected to it. Originally we were hoping at this point to go straight up into the attic above, but it turns out the roof doesn't have a very steep slope, so along an outside wall such as this there is not very much room between the floor of the attic and roof.


So instead of going up into the attic, the vent runs along the ceiling across the studio (from the hood at the right of the picture, towards the left).















Then the vent goes through the studio wall and into Shane's portion of the workshop, where the blower for the ventilation is located.











The blower is located inside the box in this photo. Air comes in from the right of the picture, where the wall to the studio is at, and exits on the left of the box. The blower is currently set on med-high speed, which corresponds to about 1700CFM with static pressure around .6 (its pretty high static pressure due to the length of the run and number of bends). Since the opening on the hood is about 6.6'x3.3', this should be plenty of air movement.


Directly below the blower box, and not visible in this picture, is the incoming air from a swamp cooler.

Ducting will eventually be arranged so that the cooled air can be directed either into Shane's half of the shop, or into the glass studio. Because the swamp cooler sits right behind this wall, we cannot have the exhaust from the hood exit here!





After exiting the box, air continues along the venting through the rest of the workshop (again from right to left).















And finally exits the workshop! Total length of the duct run is 25'. This puts the exhaust vent over 12' from the swamp cooler intake and over 20' from the window and bench where the main make up air comes in.



















Finally, here is an initial smoke test of the ventilation system. For this test, we set off 2 smoke "grenades" on the bench, let the hood and bench area fill up with smoke, then turned on the blower. The video starts just after the smoke has maxed out, and the blower is turned on about 2 seconds into the video, so you can get an idea of how quickly it is sucked out.


Torch problems!

What is going wrong here? This GTT Lynx has the propane set to 5psi and the oxygen concentrator at 10psi. The volume control on the concentrator is set to around 9 lpm. However, the flame is slightly reducing, and as the oxygen concentrator goes through its cycle, the flame grows longer candles and is even more reducing. Turning up the oxygen knob on the torch results in more noise and hissing, but no improvement in the flame.